Stability and outcome of persistent infant crying

STABILITY AND OUTCOME INFANT CRYING

OF PERSISTENT

Ian St. James-Roberts Susan Conroy Catherine

Wilsher

Thomas Coram Research Unit London University

Six week old

Institute of Education

infants who

fussed and cried for 3 or more hrs per day (persistent criers), evening criers, and

moderate criers were assessed using researcher and maternal measures of infant, maternal and family characteristics at 6 weeks, 5 months and 15 months of infant age. Convergent evidence of stable individual differences in negadve behavior was found between 6 weeks - 5 months and 5 - 15 months of age. Objectively hard-to-soothe

infants, particularly, were distinguished

on a range of researcher and mater-

nal measures. Between 6 weeks and 15 months, infant negative behavior was not a stable characteristic, although mothers continued to rate the same infants as fussy/difficult.

In multiple

regression

analyses,

infant negative behavior at 6 weeks did not predict maternal or researcher measures of infant negativity, temperament, behavior problems or cognition at 15 months. Maternal and family variables mediated the development of infant negative behavior.

infant crying Infant colic negative behavior maternal sensitivity social support behavior problems temperament emotional development social development sleeping problems diaries

INTRODUCTION When a baby cries repeatedly for prolonged periods, parents are understandably concerned about the reasons for the crying and whether their baby will “grow out of it.” Questions

l

about the cause and stability of individual differences in “negative behavior”* have also fascinated researchers. Reviewing the results, Fish, Stifter, and Belsky (1991) concluded that most studies have found, at most, low stability in negative behavior during infancy. As they

Ian St. James-Roberts, Thomas Coram Research Unit, 27/28 Woburn Square, London WC1 H OAA, U.K.; e-mail:

[email protected]. INFANT

BEHAVIOR

& DEVELOPMENT

21 f3), 1998,

Copyright 0 1998 Ablex Publishing Corporation

pp. 41 l-435

ISSN 0163-6383 All rights of reproduction

in any form reserved.

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INFANT

noted, such low stabilities are noteworthy evidence of instability. In contrast to the general community research reviewed by Fish et al. (1991), two recent studies found evidence of long-term problems in children who had colic in the first 3 months of infancy. Although this term is poorly defined, colic studies share a concern with infants who cry extraordinary amounts. The most widely used definition of colicWessel, Cobb, Jackson, Harris, and Detwiler’s (1954) “Rule of Threes”-+lefines colic as “paroxysms of irritability, fussing or crying lasting for a total of more than 3 hrs/day and occurring on more than 3 days in any I week” (p .425-426). Forsyth and Canny (1991) found that infants reported to have colic and feeding problems in the early months were particularly likely to have behavior problems and perceived vulnerabilities at 31/2 years of age. Similarly, Rautova, Lehtonen, Helenius, and Silanpaa (1995) found a higher rate of temper tantrums and sleeping problems in infants previously selected as colic cases than in control infants at 3 years of age. This apparent discrepancy between the findings of community and colic studies provides an opportunity for research into the factors which distinguish stable from unstable negativity. There are at least two different ways of interpreting the findings. Firstly, both early persistent crying and stable infant negative behavior may be due to the temperamental characteristics of particular infants. Stability of individual characteristics over age is generally agreed to be a defining characteristic of temperament (Goldsmith et al., 1987). Specifically, evidence that infants retain their rank in negative behavior in spite of the changes in mean scores which occur with age can be taken as support for a temperament explanation of negativity (McCall, 1986). Thomas, Chess, and Birch (1968) originated the idea that negative infant behavior is due to “difficult temperament’, identified in approximately 10% of children. Carey (1984) and Lester, Boukydis, Garcia-Coll, and Hole

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(1990) proposed that colic is an early reflection of such a stable, underlying, disposition. It is plausible that colic studies’ selection of infants who cry a lot may result in groups of infants who are particularly temperamentally difficult. However, this temperament explanation cannot account for two of the main features of early infant crying found in both colic and community studies: evening clustering and a crying “peak” at around 6 weeks of age, followed by a substantial decline (Barr, 1990; Brazelton, 1962; St. James-Roberts & Halil, 1991). A second possibility is that stable infant negativity is due to parents’ responses to otherwise transitory infant disturbances. This developmental explanation draws a distinction between factors which initially give rise to infant negativity and those which maintain it in the longer term. It shifts the focus of research towards an understanding of the reasons why some infants remain stable in negativity, while others do not (Fish et al., 1991). Consistent with the developmental view, Illingworth (1955; 1985) argued that colic is a early gastrointestinal condition discrete involving digestive disorder and associated pain. Subsequent studies have provided evidence that crying in the first 3 months is associated with food sensitivity in a small minority of infants (Forsyth, 1989; Lothe & Lindberg, 1989). However, others have failed to find evidence of a digestive disorder in most infants who cry persistently at this age (Miller & Barr, 199 l), or have argued that any digestive disturbance is a secondary consequence of neurological factors (Lester et al., 1990). That colic is a self-limiting condition has, however, remained a central tenet of colic research (Illingworth, 1985; Lester et al., 1990; Rubin & Predergast, 1984) and the stable problems found in Forsyth and Canny’s (1991) and Rautova et al.‘s (1994) studies are somewhat at odds with this tradition. processes, Focussing on neurological Emde, Gainsbauer, and Harmon (1974) first drew attention to the coincidence between “unexplained fussiness” in the first 3 months

Outcome

of Persistent

infant Crying

and advances in neurological functioning and social-behavioral abilities, such as social smiling, which occur at this age. They argued that a neurobehavioral reorganization or “shift” took place at this point in development, moving the infant from a largely reflexive to an increasingly social and cognitive organism as learning and communicative abilities emerged. Prechtl(l984) provided an evolutionary explanation for a neurodevelopmental reorganization in the early postnatal months. Fisichelli, Fisichelli, Karelitz, and Cooper (I 974) showed that infants increase their ability to inhibit crying after about 12 weeks of age and Gekoski, Rovee-Collier, and Carulli-Rabinowitz (1983) found that infants begin to anticipate caregiver response before it occurs at about the same age. Gustafson and Green (1991) documented the increasing coordination of cry sounds with visual regards and gestures which occurs from 3 to 12 months of age. In keeping with Emde et al’s (1974) theorizing, several large scale studies of crying in western and non-western communities have provided evidence of a “peak” in infant crying in the first 3 months, suggesting that it is indeed an infant “universal” (Barr, Konner, Bakeman, & Adamson, 199 1; Brazelton, 1962; Hunziker & Barr, 1986; St. James-Roberts, Bowyer, Varghese, & Sawdon, 1994; St. James-Roberts & Hal& 1991). In Denmark and England, 20- 25% of infants have been found to meet the Wessel et al criteria for amount of fussing and crying at around 6 weeks of age (Alvarez & St. James-Roberts, 1996; St. James-Roberts, Conroy, & Wilsher, 1995; St. James-Roberts & Halil, 1991). It seems unlikely that such a high proportion of infants would have a clinical condition. Indeed, there is evidence that the peak prevalence of clinical contact for “excessive” infant crying coincides with this infant crying peak (Alvarez & St. James-Roberts, 1996; St. James-Roberts & Halil, 1991), suggesting that most cases who come to clinical attention are at the extreme tip of the normal distribution for crying at this age. Accordingly, cry researchers have sought to explain prolonged crying at this

413

early age in terms of the neurodevelopmental reorganization posited by Emde et al. (Barr, 1990; Lester, 1985; St. James-Roberts, 1989). Currently, neither the gastrointestinal nor neurodevelopmental viewpoints provides a fully explicated, tried, and tested explanation for persistent crying in young infants. In contrast to temperament formulations, these explanations presume the factors responsible for early crying to be transitory, so that early crying should not necessarily predict later negative behavior. The outcome of early crying is expected to vary, depending on developmental and other factors. In particular, parental responses to the crying and subsequent parentinfant interactions seem likely to be important in distinguishing stable from unstable negativity. This is supported by Fish et al. (1991) and Belsky, Rovine, and Taylor (1984) who found insensitive mothering to be associated with a relative increase in negative behavior over age. Van den Boom (1994) showed that an intervention which increased maternal responsiveness led an initially irritable group of newborns to be more effective at self-soothing than control infants at 9 months of age. The parents included in the colic outcome studies of Forsyth and Canny (1991) and Rautova et al. (1994) showed a range of social and psychosocial adversities and it may be that such parents lack the resources to make the adjustments needed for good outcomes. This study’s goal was to provide evidence relevant to these theoretical formulations and the underlying question of the reasons for infant crying and negative behavior at successive ages. A limitation of the two colic outcome studies cited above is that infant crying was measured by parent reports of perceived crying problems, rather than direct measures of infant crying and other behavior. Taubman (1988) found only moderate agreement between measures of infant crying duration and parent-reported crying problems and Wolke, Meyer, Ohrt, and Riegel (1995) proposed that perceived problems may be more stable than actual infant behavior. To overcome this limitation, validated behavior diaries

414

and standard researcher measures, as well as maternal questionnaires, were used here to measure crying and negative behavior. To avoid bias through self-selection, a large community sample was screened and groups of infants selected according to the amounts the infants cried at 5-6 weeks of age. This age was chosen because it is the peak age for infant crying and parental contact with health professionals because of the crying. There were two aims. The first was to confirm whether infants selected using Wessel et al.‘s (1954) criteria for amount of fussing and crying were stable in negative behavior when re-assessed at 5 months and 15 months of age. The second aim was to assess the relative contribution of infant and parental variables in predicting infant negative behavior, temperament, behavior problems and cognitive development at 15 months of age. Five months was chosen as the first follow-up age because colic is generally considered to be over by this age. Fifteen months was targeted for the outcome measures because of evidence that infant temperament is stable by this age (Braungart, Plomin, DeFries, & Fulker, 1992; Cherny, Fulker, Corley, Plomin, & DeFries, 1994).

ME7-HOD

Participants The participants were selected in two stages. Initially, 597 mothers were approached in the postnatal wards of a large maternity hospital serving the general community in London, UK. Except that multiple births and infants admitted to intensive care were excluded, the mothers were approached unselectively and invited to participate in a study of individual differences in infant crying by completing diaries and questionnaires and allowing home assessments by researchers. 551 (93%) gave informed consent to participate in the study. Secondly, 530 of the mothers (89% of those originally approached) were successfully interviewed when their babies were 4-5

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weeks of age using a telephone version of the Crying Patterns Questionnaire (CPQ; St. James-Roberts & Halil, 1991). The CPQ is a survey instrument which asks mothers to report the amount (minutes or hours) of fussing and crying which have usually occurred (i.e., on most days) in the morning (6 a.m.noon), afternoon (noon-6 p.m.), evening (6 p.m.-midnight) and night (midnight-6 a.m.) during the previous week. Wolke, Gray, and Meyer (1994) and St. James-Roberts, Hurry, Bowyer, and Barr (1995) found satisfactory agreement between the CPQ and diary measures of crying. Here, the CPQ was used to screen and select three groups of infants according to their reported crying amount and pattern: 1.

2.

3.

Persistent Criers (n = 67), who met Wessel et al.‘s (1954) criteria by fuss\crying for 3 or more hrs per day most days in the last week.“Persistent criers” is the preferred term because of the ambiguities associated with the word “colic.” Evening Criers (n = 38), who usually fuss\cried for an hr or more in the evenings; 30 min or less in all other periods of the day and less then 3 hrs in total. Moderate Criers (n = 55) who fuss\cried for 30 min or less in each period of the day.

All eligible persistent and evening criers were asked to participate in the follow-up assessments at home. Moderate criers were asked on a first-comer basis, so far as the researchers’ schedule for visits that week allowed. A further 22 mothers of persistent criers (25% of the 89 asked) declined to allow the follow-up assessments, as did 18 (32%) of the 56 mothers of evening criers asked and 14 (20%) of the 69 mothers of moderate criers asked. The chief reason given was the inconvenience of the visits, which were scheduled to coincide with the time of maximum crying, typically the evening. Mothers and babies who dropped out did not differ from the participat-

Outcome

ofPersistentInfantCrying

ing cases in age, ethnicity, this baby’s sex, obstetric history or amount of crying on the CPQ. However, they were more likely to have one or more previous children than those who took part (Pearson Chi-Square = 8.46, Idf, p = .004) and, presumably, this added to the inconvenience of the home visits. The CPQ, demographic and other particulars of the three selected groups and the community sample are examined in St. JamesRoberts et al. (1995). There were no differences in demographic characteristics, infant sex or parity between the three selected groups. However, compared to UK mothers in general, those who participated in the home assessments were slightly older, of a higher social class and less likely to be Asian or African-Caribbean, while the assessed infants were more likely to be firstborns.

Procedures Assessments At Birth

of Obstetric Complications

Each infant’s medical records were scored for evidence of medical sub-optimalities during pregnancy and the perinatal period, using a standard scoring procedure. Details of the scoring and findings for the relationships between these variables and infant crying at 6 weeks and 5 months of age will be reported in a future paper. In brief, obstetric sub-optimality accounted for a small proportion, at most, of the variance in infant crying at these ages. For example, using multiple regression analysis, composites of obstetric variables predicted 14% and 9%, respectively, of the variance in 6 week diary and Infant Characteristics Questionnaire measures of negative behavior. Assessments At Six Weeks of Age At 5-6 weeks of infant age, the selected groups were followed up at home by separate researchers from those who recruited and screened them. In addition to 24 hr audiore-

415

cordings of infant vocalization, measures were obtained:

the following

Maternal diaries of infant and parental behavior completed prospectively over 3 days. Following Hunziker and Barr’s (1986) original, these diaries consisted of four, 6 hr “time-ruler” charts, corresponding to the morning (6 a.m.-noon), afternoon (noon-6 p.m.), evening (6 p.m.-midnight) and night (midnight-6 a.m.). Each time ruler had a printed scale, allowing behaviors to be shaded in more or less as they occurred, with a resolution time of 5 min. Infant behaviors were shaded in on the top section of the ruler, and caregiver activities on the bottom section, against the same time-scale. Mothers were asked to shade in four main categories of infant behavior: feeding, sleeping, awake-content and distress. For each distress period, they distinguished fussing, crying or colic behavior, taking account of definitions printed on the diary: l

l

l

Fussing: “baby is unsettled and irritable and may be vocalizing but not continuously crying.” Crying: “periods of prolonged distressed vocalization.” Colic: “bouts of intense, unsoothable crying and other behavior, perhaps due to stomach or bowel pain.”

Caregiver activities were categorized as holding, playing/talking, soothing, and routine infant care. Two activities occurring simultaneously (e.g. holding + soothing) could both be recorded. As well as written instructions, the diaries contained an example page to illustrate what a completed diary might look like. Researchers explained and began the diaries with the mothers during the home visits and a telephone number was provided for queries. The diaries were kept for 3 successive days where possible. In practice, 82 % of the 160 mothers kept them for at least 1 day, 72% for 2 days and 56% for 3 days, while 18%, evenly divided between the three groups, failed to

INFANT

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complete a diary. The diaries’ validity in measuring infant fuss/crying has been demonstrated in previous studies (Barr, Kramer, Boisjoly, McVey-White, & Pless, 1988; St. James-Roberts, Hurry, & Bowyer, 1993). Following these studies, the available diaries for each infant were aggregated to produce a single, average 24 hr record for each infant. Measures of fussing, crying and colic behavior were then totalled to provide a single figure for the number of minutes of negative behavior in 24 hrs. Twenty-four hour audiorecordings made concurrent with the 6 week diaries from the present participants confirm the validity of the diary figures for the durations of negative behavior and group differences reported here (St. James-Roberts, Conroy, & Wilsher, 1996). Similarly, researcher observations made in the home confirm the diary differences in maternal behavior (St. James-Roberts, Conroy, & Wilsher in press).

Standardized

researcher

observations

Each home visit by the researchers lasted approximately 4 hrs and was designed to coincide with the period of the day when the infant usually cried the most. Except for standard measures of infant consolability described below, the researchers made non-participant observations of infant and maternal behavior throughout the visit, using a standard observation protocol similar to those employed in previous research (Fish & Crockenberg, 1981; Isabella, Ward & Belsky, 1985; St. James-Roberts & Wolke, 1988). During each 30 s, the researcher recorded any of a predefined set of infant and maternal behaviors which occurred. Infant behaviors included state (awake, fussing, crying, drowsy, sleeping) plus limb and body movements; while the maternal behaviors included looking at, talking to, physical stimulation (pats, strokes, massages, rocks), affectionate vocal/facial expressions, play, use of pacifier, diaper change, other routine care, holding, walking/carrying, use of devices such as pram or swing not involving body contact, and being out of sight or hearing. The behavof maternal

and infant behavior.

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iors were concretely defined in a written manual and the two observers were trained in the method during a two month pilot period, until inter-observer reliability of better than 90% was established for all the observed behaviors. The observers were blinded regarding each infant’s group and each observed equal numbers of persistent, evening, and moderate criers and their mothers. Validity is supported by the finding that the observations successfully distinguished the behavior of persistent criers and their mothers from those of other infants and mothers at 6 weeks and 5 months of age (St. James-Roberts et al., in press). On finishing her observations, each researcher also completed four 5-point rating scales to provide global judgements of each mother’s sensitivity and displayed affection during infant fuss/crying periods, and during settled periods, throughout the observation. Similar rating scale measures have proved to be effective and reliable indices of maternal characteristics in previous research (Ainsworth, Bell, & Stayton, 1974; Crockenburg & McClusky, 1986; Fish et al., 199 1; Isabella, 1993) and Schaefer (1989) has pointed out that they often yield higher cross-time stabilities and predictions of infant behavior than observation measures. Based on Ainsworth et al. (1974) and Fish et al.‘s (1991) criteria, written definitions and instructions tying the judgements closely to observable behaviors were used to anchor the ratings, while the observers were also trained in Murray, FioriCowley, Hooper, and Cooper’s (1996) methods for assessing maternal sensitivity, as described below. The global ratings were made blinded to each mother and child’s group. High sensitivity, defined by attentive, contingently responsive behavior was given a score of 5, while a low score was given where mothers were unresponsive and/or intrusively responsive to their babies’ signals. Similarly, frequent maternal verbal or facial expressions of positive affect, together with low rates of negative affect, were rated as 5; and low positive affect/ high negative affect as 1. Validity is supported by evidence that the ratings corre-

Outcome

ofPersistentInfantCrying

lated significantly with the observations and distinguished the behavior of mothers of persistent criers” from other mothers at 6 weeks of age (St. James-Roberts et al., in press).

Infant consolability measures. Standard measures of each infant’s consolability were made during each instance of fussing or crying which occurred during the home visit. Consolability scores were based on a graded set of soothing procedures, similar to those included in the Neonatal Behavioral Assessment Scale (Brazelton, 1986), which the researcher employed where a mother’s attempts to soothe an infant continued to be unsuccessful after 15 min. In such cases, the researcher intervened with the mother’s permission. initially talking to the infant only and then gradually increasing the number of soothing stimuli used until the infant was successfully consoled, or could not be consoled at all. Each infant received a score on a scale from 0 (never inconsolable by the mother) to 7 (could not be consoled by mother or researcher).The stimuli and scoring are described in more detail in St. James-Roberts et al. (1995).

Maternal questionnaire measures. Lastly, each mother completed validated questionnaire measures of perceived infant temperament and of her psychological state and approach to parenting. These were: (i) the Infant Characteristics Questionnaire (ICQ; Bates, Freeland, & Lounsbury, 1979), a widely used measure of perceived infant temperament (eg, Lester, Boukydis, Garcia-Coll, Hole, & Peucker, 1992); (ii) Crockenberg and Smith’s ( 1982) IO-item scale of maternal responsiveness and attitudes towards “spoiling” and leaving a baby to cry (also used by Fish et al., 199 1; Stifter & Braungart, 1992); (iii) the Schedule-Demand Inventory (Power, Gersenhorn, & Stafford, 1990) a measure of maternal flexibility versus scheduling of infant feeds, playing times, naps and night-time sleeping; (iv) the Edinburgh Depression Scale, a 10 item measure of maternal depression suitable for

417

the postnatal period and with established clinical norms (Cox, Holden, & Sagovsky, 1987).

Assessments At Five Months

of Age

At 5 months of age, a second home visit lasting approximately 21/2 hrs took place, usually in the morning or afternoon. The 6 week diaries and questionnaires were repeated and two questionnaire measures were added. The Dyadic Adjustment Scale is a commonly used measure of a mother’s satisfaction with and adjustment to her relationship with her partner and family life (see Spanier & Thompson, 1982 for a review). The Parenting Daily Hassles scale measures the mother’s perception of the number and degree of minor daily stresses associated with everyday childcare and family life (Cmic & Greenberg, 1990). As well as these maternal measures, three objective measures were made: the observation used at 6 weeks was repeated, GarciaCoil, Halpem, Vohr, Seifer, & Oh’s (1992) Behavioral Assessment of Infant Temperament (BAIT) was carried out, and Murray et al.‘s (1996) procedure for measuring maternal sensitivity and intrusiveness was completed. The BAIT is a standard researcher assessment of an infant’s responses to a preset sequence of 16 visual, auditory, and tactile stimuli. Although developed for the laboratory, the procedure was here carried out in the infants’ homes. It takes approximately 15 min, during which the experimenter presents each stimulus for 30 s. The stimuli are designed to increase in intensity, progressing from the examiner’s face and voice through inanimate toys to include masks, a jack in the box, and an “overwhelming toy” (a moving toy robot with flashing lights and sounds). The infant’s behavior is videorecorded and subsequently scored using a written protocol to provide measures of six summary dimensions: sociability, soothability, irritability, approach, inhibition and neutral. Garcia-Co11 et al. (1992) and Walk, Zeanah, Garcia-Coll, and Carr (1992) provided evidence of the BAIT’s internal and interobserver reliability and discriminant and con-

418

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current validity. To confirm reliability here, 13 infants from the present participants were scored independently by two researchers. Correlations between the two scorers’ summary scores for the six dimensions ranged from .90 for neutral to .99 for inhibition. For the Murray et al. (1996) procedure, the mother was asked to play with her baby for 5 min, as she normally would. No other instructions were given. The 5 min of interaction were videotaped for later analysis. Except that the mothers were not given toys (although some chose to use their own) this method is similar to those employed in Fish et al.‘s (1991) and Stifter and Braungart’s (1992) American studies. The play situation is designed to be more or less standardized and mildly stressful, so that a mother’s resources in interacting with her baby are assessed. The videotapes were later coded by two observers trained to reliability by Murray’s group. The two measures to be reported-of maternal sensitivity and intrusiveness-were summary scores based on 5point rating scales, with each scale point anchored by a written definition. High sensitivity ratings were given to mothers who exhibited positive affect, little or no anger, irritation or frustration towards their babies, responded rapidly, were undemanding and showed sensitivity to their babies’ signals. Low sensitivity ratings were given for cold, critical, unresponsive, demanding or insensitive maternal behavior. High intrusiveness ratings were given for frequent intrusive behaviors and/or speech; low intrusiveness ratings for few intrusive interruptions, interactions and/or speech. The ratings were made blinded and the observers did not rate mothers they had observed. Inter-rater agreement, assessed for 16 of the study infants, showed correlations of .96 for the sensitivity and .90 for the intrusiveness scores. Murray et al. (1996) have shown that the sensitivity and intrusiveness scores from this procedure differentiate depressed from control mothers.

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15 Month Assessments At 15 months, a final home visit took place, lasting approximately 90 min. The 5-month diaries and questionnaires were repeated and other outcome measures were added. To allow for development, the diary was modified so that fussing and/ or crying were recorded as a single variable, while mothers were asked to record instances of temper, frustration or irritability as a second variable. A ‘structured interview with each mother was used to obtain demographic information and to screen for infant health and feeding problems and the use of non-parental childcare. Two additional questionnaires were included. The Behaviour Screening Questionnaire (BSQ) is a brief, widely used screening interview for infant behavior problems employed in a previous crying outcome study (Richman, Stevenson, & Graham, 1982; Forsyth & Canny, 1991). Because of the ages of the subjects, three items concerned with toilet training and concentration were omitted (see Hewitt, 1990). The Negative Life Events scale, adapted from Brugha, Bebbington, Tennant, and Hurry (1985) is a 17 item questionnaire which measures significant family disruptions, such as serious illness, deaths, separations, unemployment and relocations, over the preceding year. It was included because of the importance of such social stresses for children’s development and behavior problems (Goodyear, 1990). Lastly, each infant was assessed by the researcher on the Bayley Scales of Infant Development and Infant Behavior Record (IBR), which scores an infant’s behavioral responses to the Bayley test procedures (Bayley, 1969). The Bayley assessments were made by researchers trained to reliability using video and live assessments, following the Bayley (1969) manual. Because the IBR assesses infant behavior under standard, mildly challenging circumstances it has been used as a measure of temperament in previous studies. (Braungart et al., 1992; Matheny, 1980). The factor-analyzed scales constructed by Matheny

Outcome

of Persistent infant

419

Crying

TABLE 1 Mean

(SD) Figures for Maternal

Measures

of Infant

Three Groups

Negative

Behavior

at Each Age in the

of Infants ANOVA

Moderate

Diary 24 hour min of negative behavior 6 weeks 5 months 15 months ICQ Fussy/Difficult Score 6 weeks 5 months 15 months SSQ Score 15 months Sample SIZW

Criers

Criers

Duncan f

P

MR test

116

(84)

167

(75)

221

16.3

.OOOl

36 29

(27) (22)

65 36

(46) (23)

102 34

(70) (26)

16.6

.OOOl

MiEcP M
16.8 15.2 27 2.7

(5) (4) (6) (2)

21.9 19.5 31 3

(4) (6) (6) (2)

25.3 21.6 33 4.1

(6) (6) (8) (3)

37 15 7.3 4.3

.OOOl .OOOl ,001 ,015

M
Duly b wwks: Moder.ate Cwrs. N = 45;

N = 10; t’&,tenl

Persistent

Criers

Measure

Crrrs:

Evening

Evrn~ng Crcrs.

N = 33; Persisfwf (rice:

(105)

N = 54, 5 month,

Modrrate (r~tn

N = 17, Evrnmg

Criers: N = 48: 15 months. Moderalr Crws: N = 34, Evewing Criers. N = 28; Pwa~wnt Crcrs. N = 34; ICC>0 week\, Mod-

~rdtcl Cnrrs. N = 45; Evening Cr~en: N = 33; PAstrnt N = 54; 15 months: Moderate Crirrx

Crwrs: N = 59; 5 month,. Modwnle (-riers: N = 38; Evenmg Crirrs. N = .$I; I’rru~tent (.riw,

N = 37; Evening Crws: N = 28. Persistent Crws:

(1980) and replicated by Braungart (1992) were used to score the IBR.

et

al.

RESULTS The analyses are divided into four stages. The basic issue of stability in infant negative behavior is examined using maternal measures in stage one, and using researcher together with maternal measures in stage two. Thirdly, multiple regression analyses are used to identify the infant and maternal characteristics associated with good and poor outcomes at 15 months of age. Lastly, change-score analyses are used to assess whether maternal characteristics are associated with relative improvement, or worsening, of infant negativity between 6 weeks and 15 months of age.

Stability in Maternal Measures In fan t Negative Behavior

of

The mean (SD) number of minutes of negative behavior recorded in the diaries and the ICQ fussy/difficult scores for the three groups at each age are summarized in Table 1. At 6 weeks and 5 months, diary negative behavior

N = 38; BSQ: Modpratr Cricrr, N = 47; Ewnmg (~rwr~. N =

is a composite, predominantly of fussing and crying together with small amounts of colic behavior; while at 15 months it is a composite of fuss/crying and temper/frustration/irritability behavior. To ensure that the results were not distorted by cornpositing the behaviors, all the correlational and odds ratio analyses were duplicated using individual behaviors and where these predicted better than the composites this is indicated. Table I also gives the BSQ findings for the three groups at 15 months. For the infants as a whole, Table 2 provides correlational figures for the stability of individual differences at successive ages. For the diaries, the correlations are supplemented by odds ratio figures in the text. The odds ratios give the likelihood that an individual who is in the top 25% in diary-measured negative behavior at one age will remain in that quartile at a subsequent age, relative to the likelihood that an infant not in the high negativity group at age one will enter that group. For example, an odds ratio of 2 signifies that high negativity group infants at one age are twice as likely to be in that group at a subsequent age, compared to other infants in the study. Because not all mothers completed diaries or questionnaires, while there was some

420

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Vol. 21, No. 3, 1998

TABLE 2 Correlation

Figures for the Stability Infant

of Individual

Negative

Behavior

Differences

DIARY M&3St/K~

6 weeks

DIARY 6 weeks

..s4*** .I 7

5 months 15 months

in Maternal

Measures

of

Over Age ICY

5 month5

15 month<

38* * *

6 week,

.5 months

J 5 months

-

ICQ 6 weeks

.47***

.41***

.O.i

-

Ti months 15 months SSQ 15 months

.31** .1)7

.4t3*** .:30**

.l 0

.61*** .40***

.5.5***

.I 2

.2?J**

.2.5*

.I?9**

.I .3

attrition

over

age.

the

participant

sizes

3h* * *

are

given for each analysis. The diaries show the expected reductions in mean amounts of negative behavior over age, with especially marked reductions between 6 weeks and 5 months. The increase in ICQ mean scores at 15 months reflects the use of more items to measure fussy/difficult behavior at this age (Bates et al., 1979). As well as these developmental changes in average levels of negativity, the findings show clear and stable group and individual differences in negative behavior from 6 weeks to 5 months of age. Using odds ratios, infants in the top 25% for diary measures of negativity at 6 weeks were five times as likely as other infants to be in this group at 5 months of age. As might be expected. the diary and ICQ measures correlate substantially within this age-range. For instance, 6 week diary negative behavior correlates .47 @ i: .OOl) and .3 1 @ = ,001) with the 6 week and 5 month ICQ fussy/difficult scores, respectively. By 15 months, the diaries no longer showed a difference in negativity between persistent criers at 6 weeks and other infants. Similarly, the correlation between 6 week and 15 month negativity was insignificant and infants in the highest quartile in negative behavior at 6 weeks were not especially likely to be in that quartile at 15 months. Infants in the top quar-

.49***

tile for diary fussing at 6 weeks were twice as likely to be in the extreme negativity group at 15 months, suggesting that fussiness at this age, although not strongly so, is more predictive than crying. Even so, the 6 week diary measures did not predict 15 month negativity well. In contrast, the 5 month diaries predicted 15 month negativity reliably and moderately strongly. Using odds ratios, infants in the top quartile in diary negative behavior at 5 months were three times as likely to be in the top negativity group at 15 months of age. Compared to the diary, the ICQ fussy/difficult scores distinguished between the groups and individual infants in a more stable way. As Table I shows, persistent criers at 6 weeks were distinguished as fussy/difficult on the ICQ at 15 months as well as on the BSQ behavior problems score. Similarly, the ICQmeasured individual differences in fussy/ difficult behavior were stable across all three ages, although the correlation of 0.4 between 6 week and 15 month scores was moderate. The 6 week ICQ fussy/difficult score did not predict the 15 month diary measures. Although not shown in the Tables, fussy/difficult infants were also distinguished by their ICQ predictability, adaptability and persistence subscores. Persistent criers were significantly more unpredictable at 6 weeks (y = .04) and 5 months (p = .04) and more unadaptable

Outcome

of Persistent

421

infant Crying

ment conditions will also demonstrate the generality of the infant characteristics, that is, that they are not confined to mother-infant interactions. For the infants as a whole, correlation matrices were used to examine the relationships between researcher measures, and between researcher and maternal measures, of infant negativity within and between ages. These revealed a modest number of significant and theoretically coherent correspondences within the first 5 months. For example, observed negativity at 6 weeks correlated 0.30 (p < ,001) with the 6 week diary measure, 0.22 (p = .Ol) with the 6 week ICQ score and 0.28 (p = .OOl) with observed negativity at 5 months. At 5 months, observed fussing (but not crying) correlated 0.19 (p = .04) with the 5 month diary measure of negativity, 0.20 with the 5 month ICQ fussy/difficult score (p = .02 ) and 0.23 (p = ,006) with the BAIT soothability score. However, only one correlation, between the 5 month ICQ fussy/difficult and BAIT soothability score (0.42, p < .OOl) exceeded the 0.4 level. Although supporting the validity of maternal reports of infant negativity and its stability in the first 5 months, the degree of convergence is modest, suggesting

.0009) and persistent @ = .04) at 15 months. Correlations between ICQ subscores, although significant, were generally smaller than the correlations between the fussy/difficult scores at successive ages in Table 1. Of the ICQ subscores, the fussy/difficult score consistently showed the strongest relationships with other negativity measures. In sum, these findings based on maternal observations show that negative behavior is a stable infant characteristic between 6 weeks and 5 months, and between 5 and 15 months of age. There is little stability in negativity between 6 weeks and 15 months on diary measures, but moderate stability in the ICQ rating measures of fussy/difficult behavior over this period. (p =

Convergence

Between Researcher and

Ma ternal Measures Convergent evidence is important to establish the validity of the maternal reports and rule out the possibility that the findings are due to subjective bias. Since children’s behavior is affected by situational variables (O’Brien, Johnson, & Anderson-Goetz, 1989), evidence that infant individual differences are confirmed by researchers under standard measure-

TABLE 3 Comparison

of Hard-to

Console

Researcher

Measures

with Other

Infants on Maternal

of Negative

and

Behavior Anova

Measure

Consolable

f

Hard-to-Console

P

6 WEEKS

Mean (SD) diary min fuss/cry ICQ Fussy/Difficult Observed

score

per cent fuss/cry

164

(102)

204

(94)

3.1

21

(6)

25

(6)

10.6

.OOl

25

(13)

34

(14)

-3.2*

.002*

65

(55)

104

(76)

6.9

18

(6)

22

(8)

a.4

,004

2.7

(2)

i .a

(1)

6.2

.Ol

.09

C.2)

.28

C.5)

30

(7)

33

.08

5 MONTHS Mean

LSD) diary mins fuss/cry

ICQ Fussy/Difficult BAIT sociability

score

score

BAIT soothability

score

11.8

.Ol

,001

15 MONTHS ICQ Fussy/Difficult “Mann-Whitney Sample sizw

score

b wrrk IIidry: Consolable: n = 107; Hatnl-lo-Consolr.

Obs~r~df~~n~~Consolablc~:n = 130; Hard-to-Cons&: Cons,lablr

(8)

3.5

.06

U

n = 100; Hdrd-lo- Cons&

n = H4: H.m-to-Conu++.

n = 18

n = 24; ICQ: Cons&blr~: n = 11 1; H~d-1~~-Cwsolr:

n = 27;

n = 29; ‘1 month I11ary Conaol~blr~ n = ‘37; Hanl-ho-Consolr: n = 18, KQ:

n = 22; BAIT, ~onsolahlr: n = 11 6; Hanl-lo-(:l,nsolr.

R = 2i. 1 i month I(:(): Conwlal~lc~.

INFANT

422

& DEVELOPMENT

Vol. 21, No. 3, 1998

were no significant differences between the groups and all three obtained above average mental development scores, consistent with their predominantly middle class background. To provide a more exhaustive analysis of the outcomes of persistent crying and the variables associated with stable and unstable negativity, multiple regression analyses including both infant and maternal variables were used to predict the 15 month Diary, ICQ, BSQ and Bayley measures listed in Table 5. These analyses identified the most significant predictor variables when other variables were taken into account. Kurtosis and skew for the outcome variables were within acceptable limits. Because “sleeping through the night” is an important concern for parents and a common variable in research, a dichotomous 15 month diary infant “sleep problems” variable (wakes at least once, versus sleeps without waking, between 11 p.m. and 5 a.m.) was created and logistic regression used to predict this outcome. Correlation matrices including all the obstetric, infant behavioral, infant health, maternal and family variables assessed at birth, 6 weeks, 5 months and 15 months of age were first examined to identify significant relationships between the variables within and between ages. Variables found to correlate significantly with the 15 month outcomes were entered simultaneously and forward iteration procedures (Norusis, 1993) used to identify the optimum variable combination for explaining variance in the outcome measure. The resulting variables and proportion of variance (R’) in the outcome variables accounted for are listed in Table 5. Blank cells in Table 5 signify that

that measurement and situational factors are important. Moreover, there were very few significant correlations between the researcher 6 week or 5 month measures of infant negative behavior and the 15 month outcome measures, and none which exceeded 0.3. More consistent evidence of stability was obtained when the infants’ consolability scores at 6 weeks were used to predict their concurrent and later behavior. Most infants wereeffectively soothed by their mothers and only one who could not be soothed by the mother was immediately soothed by the researcher. Consequently, these analyses were based on dichotomised soothability scores, such that the 29 infants who were difficult or impossible to soothe for both mothers and researchers were compared to the remaining 13 1 infants. Most (2 1) of the 29 infants were persistent criers, although most persistent criers were successfully soothed by their mothers. Table 3 summarizes the findings. Infants who were objectively hard to console at 6 weeks were clearly distinguished on an array of researcher and maternal measures at 6 weeks and 5 months of age. Although the diary difference at 6 weeks is borderline in statistical significance, this difference becomes significant (p = .04) if one extreme, outlier. score for a consolable infant is omitted from the analysis. Inconsolable infants were also distinguished by high maternal ICQ fussy/difficult ratings at 15 months, although not by the diary or Bayley measures.

Multiple Regression Modeling Month Infant Outcomes

BEHAVIOR

of 15

Table 4 summarizes the Bayley scores for the three groups of infants at 15 months. There

TABLE 4 Mean

(SD) 15-Month

Infant

Behavior

Bayiey

Record

MO&r& Measure

Mental

criers

(I 3.0)

119.8

18.1

(3.5)

17.3

(3.3)

(4.1)

25.9

(3.6)

24.2

(3.7)

(2.3)

13.2

(1.4)

13.4

(2.4)

IBR Task Orientation

17.1

(3.3)

IBR Affect-Extraversion

24.5

IBR Activity

13.4

Index

Persrstent Criers (n = 54)

cr1 = 301

(I 3.2)

Development

and

of Infants

Evening Crier\

(n = 4 7) 119.2

Mental

Index

Development

Scores for the Three Groups

12.3

(14.0)

Demographic and health

5 m infant

More diary fussing .49

TABLE 5~

BSQ Outcome

15 Month

Diary,

More fussy/difficult (ICQ)

Measures

Regression Analyses to Predict

Less diary sleep

Results Using Multiple

.45

ICQ and

Mow diary distress

Lower sensitivity/affection rating More help with housework .25

P

2 2 zx 2 3 F G -i 3 00

$ 3 rD 0

for infant height/

problem5

Clinic contxt wqht

Demographic

health

TABLE 58

.Lh

contact for infant height/

Bayley Outcome

Mother

in rna~~~l occupation

weight problemi

Clinic

Regression Analyses to Predict 15 Month

ad

Results Using Multiple

.40

.LO

Measures

solely

parental

child-we

.22

Outcome of Persistent infant Crying

no variables from that set were significant in the regression models. The beta weights give a guide to the relative importance of each predictor variable in predicting changes in the outcome variable. All variables in the table made a statistically significant and sizeable contribution. As Table 5 shows, the combined predictor variables accounted for substantial proportions (ranging from 20-41%) of the variance in outcome measures. To facilitate interpretation, results show the variables which predicted negative or “poor” outcomes. Table 5b shows the Bayley results, such that low Affect-Extraversion, Orientation, MD1 and Activity scores have been selected as poor outcomes. AffectExtraversion is a unidimensional scale of the extent to which an infant is positive, outgoing and socially interactive with the examiner, so that a poor score on this dimension approximates fairly closely to a negativity measure. Task Orientation identifies infants who were interested in and showed attention and responsiveness to the Bayley stimuli, so that a poor score both on this and the MD1 cognitive assessment seem undesirable outcomes. According to the IBR manual, intermediate levels of activity, rather than high or low levels, are optimal. For the purposes of Table 5b, a low Activity score has been designated negative, for consistency and because low activity levels are associated with medical risk in these findings. It should be noted that activity level is not a negative behavior, as defined here but has been included along with other IBR measures because of their relevance as potential indices of temperament, reactivity and selfregulation at this age. Broadly, the variables found to predict poor outcomes are theoretically coherent and consistent with the literature. For instance, previous studies have shown that breast fed infants are more likely to have sleeping problems than bottle fed infants (Elias, Nicolson, Bora, & Johnston, 1986; Wright, 1993). Overall, the logistic regression was 80% correct in predicting the 29 of the 82 infants (35%) in this analysis who woke at night at 15 months, but this

425

prediction was more accurate for infants who did sleep through the night (9 1% correct) than infants who woke (62% correct). Especially noteworthy is that none of the 6 week measures of infant negative behavior, not even the consolability scores, predicted any of the 15 month outcomes in the regression analysis. Of the 6 week infant measures, only the observed time drowsy made a significant contribution, to the Bayley MDI. Assuming this is not a chance finding, it may indicate that infants able to maintain a drowsy state at 6 weeks subsequently performed better on Bayley MD1 tasks. The second noteworthy finding in Table 5b is the consistent evidence that measures of maternal and family variables entered all the regressions. The 6 week observation measures of maternal stimulation, involvement, affection and sensitivity, diary measures of low amount of holding, and self-report measures of an inflexible approach to babycare and lack of partner support, remain significant predictors of 15 month diary negativity, ICQ and Bayley measures, even when 5 month measures are taken into account. At 5 months, both infant and additional maternal variables entered the picture. Five month old infants who were fussy and poor sleepers on diary measures and fussy/difficult on the ICQ were likely to display negative behavior, wake at night, and score lower on the Bayley IBR measures of affect-extraversion and activity at 15 months. Among the 5 month maternal measures, relatively low levels of interaction, stimulation, responsiveness and sensitivity were associated with less optimal infant behavior at 15 months. The findings also suggest some possible tuning of mothers to emerging infant capacities at this age. For instance, mothers of infants who later slept through the night reported employing a scheduled approach to infant sleeps and feeds, and being more likely to leave their baby to cry for up to 10 min, at the 5 month stage. In contrast, mothers who reported a less scheduled approach, reluctance to leave their baby to cry, and who were observed to be lower in sensitivity or affection, had babies who later scored

426

INFANT

higher on the BSQ behavior problems measures. The finding that more help with housework at 5 months was also associated with a higher 15 month BSQ score appears counterintuitive. Since housework help was not greater among mothers who returned to work, this does not provide an explanation. One possibility, based in Teti and Gelfard’s (1991) concept of maternal efficacy, is that these mothers lacked confidence in their parenting skills and so depended more on others. Teti and Gelfard (1991) provided evidence that mothers’ perceived self-efficacy mediates whether they cope effectively and predicted that low self-efficacy mothers faced with demanding babies would have difficulty establishing harmonious relationships, which may well be the case here. None of the infant negative behavior measures predicted the infants’ 15 month Bayley MD1 scores. Instead, observed infant drowsiness, the time mothers spent holding their infants, and maternal reports of a flexible, infant-demand approach to care at 6 weeks, the time mothers spent playing with their babies at 5 months, and whether infants received nonparental childcare, each contributed positively to the Bayley MD1 scores. The latter may reflect the beneficial consequences of some non-parental daycare, or a confounding of optimum mother or baby characteristics with a greater likelihood that mothers in this group of participants would return to work by 1.5 months. Crockenberg and Litman (1991) reported that employed mothers satisfied about their employment behaved more responsively towards their children. Within this group of demographically homogeneous participants, the only demographic effect was that mothers in manual occupations had babies who were less active at 15 months. Infant gender, too, had little effect. Lastly, contacts with health clinics because of concerns about feeding problems and poor weight gain in the first 15 months were significant predictors of outcomes in two of the Bayley measures. Although not shown in the table, the persistent criers did not differ from other

BEHAVIOK

& DEVELOPMENT

Vol. 21, No. 3, 1998

groups in these postnatal health measures. Consequently, the relationships between postnatal health problems and poor 15 month outcomes in Table 5a appear to be due to the health vulnerabilities of individual infants and families, rather than to factors which are linked to crying at 6 weeks of age.

Analysis of Changes in Infants’ Negativity

Rank Over Age

In a study of factors which predicted changes in infant negativity from 3 to 9 months, Belsky, Fish and Isabella (1991) divided their participant into four groups: those who retained a high negativity rank at both ages, those who retained a low negativity rank at both ages, those who changed from a high to a low negativity rank, and those who changed from a low to a high negativity rank. Although this approach means that infants who are not especially high or low in negativity are omitted from analysis, it provides a means of assessing whether the main effect of maternal variables is to reduce negativity in infants who are initially highly negative, or to increase negativity in infants who are initially low in negativity. A similar analysis was applied to the present data set. Of the 93 infants with diary data at 6 weeks and 15 months, 20 infants were excluded from analysis because their amounts of negative behavior fell between the 45th and 55th centile at one or other age. The remaining 73 infants were then classified according to their amount of negative behavior at each age. Infants whose amount of negative behavior at 6 weeks was above the 55th centile at that age were designated the high 6 week negativity group, while those whose negative behavior was below the 45th centile were designated the low 6 week negativity group. The same method was used to distinguish high and low negativity groups at 15 months. From 6 weeks to 15 months, infants were then classified into one of four developmental trajectories: highhigh; low-low; high-low; low-high. Table 6 summarizes participant group sizes and results. The mean minutes of negative

(157) (133) (66)

(97)

409 267 115

128

Mean (SD) min of Interaction Mean (SD) min of Holding Mean (SD) min of Soothing 5-MONTH MATERNAL BEHAVIOR

Mean (SD) min of Holding

(72) (IO)

(151) (171) (101)

(Ill)

439 294 146

149

(24) (12)

(112) (102) (53)

(76)

79 18

306 177 49

101

(n = 22)

Low-Low (n=14)

71

261 89 39

83 75

Behavior

at Six Weeks and

(48)

(74) (62) (28)

(30) (30)

2

6.9 8.8 9.9

48.5 43.5

f

p

MR Test

Duncan

.I0

HL>LH

.0004 HH+HL>LL+LH .OOOl HH+HL>LL+LH: .OOOl HH+HL>LL+LH

.OOOl HH+HL>LL+LH .OOOl HH+LH>LL+HL

Anova

from High to Low or Low to High

Negative

Low-High

Low, or Who Changed

254 21

(n = 16)

(83) (31)

High-Low

(n = 21)

240 82

TABLE 6 High in Diary-Measured

High-High

with Those Who Remained

of Infants Who Remained

6 weeks 15 months 6-WEEK MATERNAL BEHAVIOR

INFANT BEHAVIOR Mean (SD) min of Negative Behavior

15 Months

Comparison

LL>LH

428

INFANT

behavior in each group at each age show that the procedure distinguished infants who remained high or low in negativity from those who changed. Although the participant exclusions and limited sizes need to be borne in mind, the diary measures of maternal behavior at 6 weeks and 5 months for each of the four groups show several noteworthy findings. First, amount of holding, which predicted the 15 month Bayley MD1 in the regression analysis, also emerges here. That is mothers whose babies changed from high to low negativity held their babies most at 6 weeks and 5 months of age, while babies who changed from low to high negativity were held least at 6 weeks of age. Secondly, the results highlight that some babies who were low in fussing and crying at 6 weeks became highly negative at 15 months. In this low-high group, mothers showed particularly low levels of holding and soothing at 6 weeks and 5 months. Thirdly, the statistical results leave open the possibility that these patterns of development apply only in some cases. For instance, although mothers of high-low babies showed consistently higher mean levels of holding and interaction than mothers of high-high babies, the differences between these subgroups are not significant. Possibly, significant differences would emerge with larger groups of participants, but it may be that high levels of holding and interaction are not successful in all cases, perhaps because some infants are resistant, or because other care variables not measured by this study are involved. In sum, these analyses show that, at least in some cases, mothers of highly negative 6 week olds who held and interacted with them a lot were rewarded by a change from high to low infant negativity at 15 months. In some cases, too, infants who fussed and cried little at 6 weeks-and whose mothers held and interacted with them very little-became highly negative in their behavior at 15 months of age. To check that these findings generalized to the infants as a whole, the multiple regression analysis was repeated, forcing the 6 week measures of infant negativity and maternal interaction, holding and soothing into the regression

BEHAVIOR

& DEVELOPMENT

Vol. 21, No. 3,1998

as predictors of 15 month infant diary negativity. Consistent with the change-score findings, this variable combination predicted 10% of the variance in 15 month negative behavior in the infants as a whole.

DISCUSSION This study set out to examine the stability of infant negative behavior during the first 15 months and to assess the relative importance of infant and maternal and family variables in accounting for 15 month outcome measures of negative behavior, temperament, behavior problems and cognition. A related aim was to examine the findings’ implications for alternative theoretical formulations about infant negativity and its development over age. Two features of the research design affect how the results are interpreted. Firstly, a community sample was screened to select three groups of infants and their parents based on the infants’ crying amounts and patterns at 5-6 weeks of age, the peak age for infant crying. The crying differences were confirmed using diaries and audiorecordings. This approach should identify infants and families who are representative of those where infants cry persistently, as well as more moderate amounts. at this age. In contrast, clinical studies of infant crying often assess participants where parents have sought help with the crying, so that the participants are self-selected and may well differ from the general community in indices of social and biological risk beyond infant crying. For example, 59% of the mothers of PapouSek and von Hofacker’s (1995) clinical sample of families with persistent criers reported marital conflict, together with a range of other social and health adversities. In comparison, in the present study persistent criers’ mothers resembled moderate criers’ mothers in reported relationships with partners. The design used here should provide a more direct, unconfounded account of infant crying and its association with parental factors and negative behavior

Outcome

ofPersistentinfant Crying

over age, although care is needed in generalizing the findings to clinical samples. Secondly, no attempt was made to measure maternal or family variables before participant selection and, therefore, the findings do not bear directly on what initially triggered the crying. Although early crying may sometimes be due to poor parenting, there is growing evidence that the crying peak in the first 3 months reflects infant variables, and that persistent infant crying often occurs in spite of highly experienced, sensitive and responsive parental care (Barr, 1990; St. James-Roberts et al., in press; Stifter & Braungart, 1992). The present study’s recruitment of substantial numbers of persistent criers from low-risk, predominantly middle-class families adds to this impression. Nonetheless, the question addressed here is whether parental responses to infant negative behavior mediate its stability and outcome. With regard to the stability of infant negative behavior, the study has provided clear and consistent evidence of moderate stability between 6 weeks and 5 months, and between 5 and 15 months. Since this finding applies to objective as well as maternal measures, it allows the conclusion that the negative behavior is not confined to mother-infant interactions or to maternal reports. In particular, infants who were found to be objectively hard to console at 6 weeks were distinguished on an array of researcher and maternal measures of negative behavior at 6 weeks and 5 months of age. Between 6 weeks and 15 months, the stability evidence was less clear cut. None of the researcher 6 week measures predicted the 15 month negativity or other measures to a substantial degree. The only exception was that infants who were objectively hard to console at 6 weeks had higher ICQ fussy/difficult scores at 15 months. Infants highly fussy in maternal diary measures at 6 weeks of age were also twice as likely as other infants to be highly negative in diary-measured behavior at 15 months. This is consistent with earlier reports that fussing is a more stable attribute than crying (Moss, 1967; Roe, 1975; St. James-Rob-

429

erts & Plewis, 1996). Even so, the degree of predictiveness from the 6 week diary and researcher measures was modest. In keeping with Fish et al.‘s (199 1) overview of previous studies, this finding provides noteworthy evidence for the instability of negative behavior during infancy. Compared to these more direct measures of infant behavior, maternal ICQ fussy-difficult ratings provided consistent evidence of moderate stability across all three ages, including from 6 weeks to 15 months. This may reflect the susceptibility of rating measures such as the ICQ to subjective bias, so that mothers’ perceptions lag behind changes which have occurred in their babies. If so, this interpretation would be consistent with Wolke et al.‘s (1995) argument that perceived problems may be more stable than actual infant behavior. An alternative explanation is that the discrepancy between the ICQ and more objective measures is due to the greater sensitivity and reliability of the ICQ in identifying aspects of behavior not assessed by the 1.5 month diaries and Bayley measures. This is credible, particularly since only a single Bayley developmental and IBR assessment was administered, while this is the first time the diary has been used in its 15 month form. Given that the diary and researcher measures provided support for the ICQ ratings at 6 weeks and 5 months, this support may also be forthcoming at 15 months if improved measures of behavior are used. Irrespective of whether these findings have somewhat underestimated the stability of infant negative behavior, regression and change-score analyses made it clear that the pathway between 6 week fussing and crying and 15 month negative behavior, behavior problems and poor Bayley scores was not inevitable. When maternal and family variables were included in multiple regression analyses together with infant variables, none of the 6 week measures of infant negative behavior predicted any of the 15 month outcome assessments. This remained true whether the outcome measure was provided by the infants’ mothers or by the researchers. In con-

430

INFANT

trast, 6 week measures of maternal involvement, responsiveness and sensitivity, as well as measures of social support, remained significant predictors of the 15 month outcomes even when the intervening 5 month measures were taken into account. By 5 months, infant negative behavior, as well as maternal and family factors at this age, joined in to contribute in explaining the outcome measurements. Evidence that maternal responses to infant crying played a critical part in mediating the 15 month outcomes also came from the use of change- score analyses to compare infants who maintained their relative amount of negative behavior between 6 weeks and 15 months with infants who reduced, or increased, in negativity. The finding was that mothers of highly negative 6 week olds who held and interacted with them the most were rewarded by a change from high to low infant negativity at 15 months of age. In at least some cases, infants who fussed and cried little at 6 weeks-and whose mothers held and interacted with them littlebecame negative in their behavior at 15 months of age. As with any naturalistic, multivariate study, care is needed in attributing causal relationships among, and in generalizing from, these findings. In particular, the 6 week and 5 month variables included in this study explained only about a third of the variance in the 15 month outcome measures. Presumably other variables, including effects of infant development and of factors closer in time to the outcome assessments, would add to this level of predictiveness. It is, however, difficult to account for the findings except as evidence that maternal and family factors have mediated the development of negative infant behavior. This interpretation is supported by consistency with the findings of other multivariate and, particularly, experimental studies which have found that measures of maternal and family factors predict the likelihood that infants will increase, versus reduce, in negative behavior over age (Fish et al., 1991; Belsky et al., 1991). In a controlled study, van den Boom (1994) found that an intervention which targeted maternal

BEHAVIOR

& DEVELOPMENT

Vol. 21, No. 3, 1998

sensitive responsiveness led to increased infant sociability and self-soothing, and to reduced crying, at 9 months of age. These earlier studies concluded that, as well as social support variables, “sensitive responsiveness’ was the core dimension of maternal behavior responsible for these outcomes. A similar conclusion applies here since, although specific maternal behaviors emerged from the analyses, these were typically correlated with other maternal variables which just failed to enter the final picture. For example, detailed analyses of the 6 week data show that the amounts these mothers held their babies were correlated with the amounts of affection they showed and how sensitively they responded to their babies (St. James-Roberts et al., in press). An interesting additional finding was that, among sensitive and responsive mothers, the use at 5 months of structured methods of care-such as scheduled feeding and being more likely to leave a baby to cry for up to 10 min-was associated with lower behavior problems scores and with sleeping through the night at 15 months of age. This, too, is consistent with van den Boom’s (1994) conclusion that “sensitive responsiveness” in isolation is unlikely to guarantee optimum infant behavior. It is reminiscent of evidence in older agegroups that care which is both warm and provides clear boundaries and scaffolds for learning is associated with low rates of behavior problems (Patterson, 1982). For parents and practitioners, these findings carry the optimistic prognosis that an infant who cries persistently in the early months is not bound to be highly negative in behavior as a toddler. Mothers of such infants who manage to sustain a high level of involvement, responsiveness, and sensitive interaction, will often be rewarded with a decline in their infants’ relative amount of negative behavior over age. For practitioners, the findings highlight the need to advise and support parents, so that their caregiving is not disrupted by their babies’ initially unrewarding behavior (Korner 1974; Thoman, Acebo & Becker, 1983).

Outcome

of Persistent

infant

Crying

This study’s second aim was to consider the implications for alternative theoretical formulations about infant negativity and its development. One implication is that Forsyth and Canny’s (1991) and Rautova et al.‘s (1994) finding that colic predicted behavior problems at 3 years of age was probably due to the vulnerable families included in those studies, rather than to the predictiveness of early infant crying itself. Consistent with Forsyth and Canny’s findings, concerns about infant health were significant in predicting the infants’ 1.5 month behavior here, but these vulnerabilities were characteristic of specific infants and families rather than concomitants of persistent crying. This reinforces the need to take sampling methods into account when interpreting the results of crying studies. A second point is that the stability of infant negative behavior found, at least to 5 months of age, adds to growing evidence which challenges the assumption that infant colic is an acute, self-resolving, condition. Other studies have shown a close correspondence between the crying features of infants diagnosed as colic cases and those of infants generally, so that the major difference seems to be in the amount of crying and in its hard to soothe nature (Barr, 1990; St. JamesRoberts et al. 1995; 1996). It may well be that these characteristics sometimes lead worried parents to contact clinicians in the belief that there is something wrong with their baby (Barr, Rotman, Yaremko, Leduc, & Francoeur, 1992; St. James-Roberts et al., 1995). Rather than resolving the question of whether early persistent crying reflects a developmental transition or infant temperament, the findings fall somewhere in between, so that both theories can lay claim to partial support. The importance of the notion of a neurodevelopmental reorganization stems partly from its implication that the period before 3 months is a qualitatively distinct stage of development, so that the mechanisms responsible for regulating behavior before the transition are quite different from those responsible afterwards. If so, negative behavior should not be stable beyond the transition.

431

The finding that individual differences in negative behavior are stable to 5 months provides a mild challenge to this formulation, but one it can accommodate by assuming that some infants are delayed in completing the transition. Alternatively, it may simply be the case that infant negative behavior changes progressively with age. A related question, not satisfactorily addressed by this study, is whether the greater stability found between 5 and 15 months, compared to between 6 weeks and 15 months, is evidence that 5 and 15 month negativity are more similar in their causes, or merely evidence of the longer interval between the 6 week and 15 month measures. It will be possible to address this in future studies. Temperament theorists, such as Rothbart and Derryberry (199 1) have argued that reactivity and self-regulation are central dimenindividuality. sions of temperamental Consolability, which emerged here as a relatively robust and stable aspect of negative behavior within the first 5 months, is essentially an assessment of an infant’s ability to regulate, that is, to stop crying. As well as pointing towards a possible mechanism for persistent crying at this age, this finding seems to identify consolability as a likely temperament measure. The 6 week consolability measures did not, however, predict the infants’ 15 month Bayley IBR scores. Because the IBR measures an infant’s responses to the mild challenges of a Bayley assessment, it has been regarded as an objective temperament measure in previous studies (Braungart et al., 1992; Chemy et al., 1994; Matheny 1980) and both the Affect-Extraversion and Orientation indices appear to assess self-regulation. So far as the IBR provides a valid measure, the findings here do not support the idea that the ability to regulate negative behavior is an enduring temperament dimension across the first 15 months. More extensive assessments will refine this conclusion and are clearly warranted by the findings from the mothers’ ICQ ratings. However, progress on this issue will also require clearer

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consensus on the features which distinguish temperament measures, since the findings here suggest that mother-infant interactions may be more substantial sources of stability in negative infant behavior than infant characteristics alone. Lastly, the findings indicate a considerable overlap in the phenomena studied by developmental, temperament and clinical researchers and suggest that these fields will benefit from a closer alliance. One result of the research carried out under the rubric of infant colic has been the provision of standard methods and epidemiological figures for infant crying and its impact at different ages. These methods should stand future studies of infant negative behavior in good stead. Acknowledgment: This study was supported by project grant 037098 from The Wellcome Trust. Eric Hadley designed and constructed the audiorecording equipment. Sandy Barker helped with recruitment, and Amanda Eve with audio-transcription, Ian Plewis advised on statistical analysis and Charlie Owen on computing. We are grateful to David Harvey and the staff at Queen Charlotte’s and Chelsea Hospital and to the families who took part.

NOTE 1.

To allow for changes in infant behavior over age, the terms “negative emotion” or “negative behavior” have been used in the literature to include infant irritability, mood and temper as well as crying. The term “negative behavior” will be used in the same way here.

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