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Adult responses to cries of low and high risk infants
INFANT BEHAVIORAND DEVELOPMENT3, 167-177 (1980)
Adult Responses to Cries of Low and High Risk Infants* PHILIP SANFORD ZESKIND University of North Carolina at Chapel Hill
Thirty parents and 30 nonparents were asked to select on a questionnaire what they considered to be appropriate responsesto taperecorded pain cries elicited from 16 2-day-old infants. Half.of the cries were from healthy, low-risk infants, and half were from healthy infants at high risk due to high numbers of nonoptimal obstetric conditions. The cries from the high-risk infants elicited from parents, but not from nonparents, responsesthat were intended as more "tender and caring" and more "immediately effective at terminating the crying" than the cries from the low-risk infants. Similarly, responses by parents, but not by nonparents, to high-risk infant cries were more consistent than to low-risk infant cries. The classification of modal responsesinto functional categories shawe~dthat 21 of 30 parents gave contact-comfort kinds of responsesto the cries of high-risk infants, while none gave undirected responses. Although the differential cry features characteristic of the high-risk infant have traditionally been used to support the differential diagnosis of central nervious system pathology, these findings we"e interpreted to support a more functional perspective of the cries of the risk infant.
Neonatal crying is a state of arousal associated with characteristic behaviors and sounds (Prechtl, 1977). The nature of the infant's cry sounds are often mentioned in neurological examinations (Prechtl & Beintema, 1964) and in pediatric textbooks (cf. Vaughan & McKay, 1975) as supporting differential clinical evaluations of the medical status of the newborn. Spectrographic analyses have defined differential acoustic features of the cries o f newborn and young infants that have been associated with a wide range o f clinical conditions in which the ~ntcgrity of the infant's developing central nervous system may have been corn*This project was partially supported by NICHHD grant no. 5 TOI HD00424-04 to the Research Training Program of the Frank Porter Graham Child Development Center and by the Biomedical Research Fellowship award to the author from the University of North Carolina at Chapel Hill. Requests for reprints should be addressed to P. S. Zeskind, Department of Pediatrics, School of Medicine, Mailman Center for Child Development, University of Miami, P.O. Box 016820, Miami, Florida, 33101. 167
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ZESKIND
promised (for a review," see Lester & Zeskind, 1979). For example, a high fundamental frequency (basic pitch) and other spectral and temporal features of the cry differentiate from controls clinically abnormal infants with signs of brain damage (e.g., Vuorenkoski, Lind, Partanen, Lejeune, Lafourcade & WaszHockert, 1968) to healthy infants who show no abnormal physical or neurological signs on routine pediatric examinations yet who may be at risk due to high numbers of nonoptimal obstetric conditions which may stress the developing central nervous system (Zeskind & Lester, 1978). Some evidence suggests that the distinctive cry features disappear with infant recovery, yet remain in the presence of abnormal sequelae (Michelsson, Sirvio & Wasz-Hockert, 1977). Thus, the cry sound may reflect the biological integrity of the infant and how that integrity changes wtih development. In traditionally a separate context, the nature of the cry sound has been studied for its social value. Although the functional effects of the cry of the normal infant have long (e.g., Sherman, 1927) and frequently been examined (Bernal, 1972; Formby, 1967; Frodi, Lamb, Leavitt & Donovan, 1978; Greenberg, Rosenberg, & Lind, 1973; Muller, Hollien & Murry, 1974; Valanne, Vuroenkoski, Partanen, Lind & Wasz-Hockert, 1967; Wasz-Hockert, Lind, Vuroenkoski, Partnaen & Valanne, 1968; Wiesenfeld & Klorman, 1978; Wolff, 1969), the study of the cry of the abnormal and at-risk infant has generally been • limited to its diagnostic utility. Yet the cry of the infant at risk, with the variations in pitch and other cry features, may have functional salience to caregivers as one part of the infant's behavioral repertoire. For example, independent of the sex or parental experience of the adult listner, the unusually low-pitched pain cries of infants with Down's syndrome are considered less unpleasant and convey a less urgent need for attention than pain cries from normal infants (Freudenberg, Driscoll & Stern, 1978). Conversely, the high-pitched cry of a premature infant is considered more aversive and elicits greater autonomic arousal in mothers and fathers than the cry of a full-term infant (Frodi, Lamb, Leavitt, Donovan, Neff & Sherry, 1978). Zeskind and Lester (1978) showed that the high-pitched pain cries of infants with high numbers of nonoptimal obstetric conditions were considered by parents and nonparents of both sexes t ° be more aversive, grating, distressing, sick, urgent, piercing, discomforting, and arousihg than cries of infants with low numbers of these conditions. Factor analysis of all subjects' perceptions showed that although the pain cries of both low- and high-risk infants were perceived along one dimension representing the "distressing" quality of the cry, a second dimension emerged in the perception of the cries of the high-risk infants which conveyed the "sick" and "urgent" nature of the cry sound. Whereas previous work has shown that the cries of the infant at risk may elicit differential attention and perceptions, the goal of this study was to find if, based just on the quality of the cry sound, the cries of the infant at risk signal differential responses and intentions that reflect the underlying perceptual dimensions of the cries. It was hypothesized that adult listeners would choose caregiv-
ADULT RESPONSES TO CRIES OF LOW AND HIGH RISK INFANTS
169
ing responses (on a questionnaire) that were (1) more "immediately effective" in terminating the unpleasant and "distressing" cry of an infant who is crying for an "urgent" reason, and (2) more "tender and caring" for an infant whose cry declares that the infant may be " s i c k . "
METHOD
Subjects Subjects were 30 unmarried college students who reported no professional experience with infants, and 30 parents living in the married student housing section at the same university. The nonparents ranged in age from 18 to 21 years of age (mean age = 18.8) and reported having no children. Parents ranged in age from 21 to 38 years of age (mean age = 29.1) and had 1 to 3 children, none of whom were less than 8 months of age. Half of each group were men and half were women. These subjects represent a separate sample of adults from that of the study of the perceptual dimensions of the cries of risk infants (Zeskind & Lester, 1978).
Stimulus Tape The stimulus tape used in this study is the same as the tape used to examine the perceptual dimensions of the cries of risk infants (Zeskind & Lester, 1978). The stimuli were selected from pain cries elicited and recorded from 24 low-risk and 24 high-risk 2-day-old infants. All infants were full term (range of 37-41 weeks), full birthweight (range of 2750--3960 grams), appropriate weight for gestational age, had both 1- and 5-minute Apgar scores of at least seven, and showed no abnormal signs on neurological and physical examinations. Although the infants showed no signs of abnormality low- and high-risk infants were defined and differentiated by the number of prenatal and perinatal events that may place the infant at risk. To evaluate the number of risk factors, a risk score was constructed using the sum of absent maternal and parturitional optimal obstetric conditions from Prechtl's (1968) scale. Lower scores of optimality (higher nonoptimal scores) resulting from the absence of optimal conditions, have been used as an indicator of the degree of risk to the infant's nervotts system (Prechtl, 1968). Low- and high-risk groups were operationally defined, respectively, as those infants having 2 or less, and 5 or more nonoptimal conditions (Zeskind & Lester, 1978). Table 1 shows the list of obstetric complications found. The groups were balanced for sex and race. A similar procedure of counting the number of obstetric complications based on the absence of Prechtl's optimal conditions has been used to study infants who may be at risk (Parmelee, Kopp & Sigman, 1976).
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170
TABLE 1 List of Obstetric CompJications
MATERNAL FACTORS age (< 18 ol > 30) single marital status parity (> 6) abortion history (> 2) Rh antagonism infection in pregnancy maternal disease edema
toxemia hypertension hypohmsion heart rate irregularities previous C-section cephalo-pelvicdisproportion bleeding during pregnancy low socio-economicstatus
PARTURITIONAL FACTORS multiple birth induced delivery prolonged labor curtailed labor abnormal presentation drugs (other than local anes.)
forceps artificial membranerupture premature membranerupture C-section wrapped cord knot in cord
A cry was elicited by a rubber band snap to the heel of the infant's foot by stretching an Arco No. 64 rubber band 15 cm along the edge of a ruler. The cry was recorded on magnetic tape on a Wollensak model 2520 tape recorder with a Wollensak directional microphone held 20 cm midline from the infant's mouth. A stimulus tape comprised of the first I0 seconds of 8 low-risk and 8 high-risk infant cries randomly selected from these two larger groups was made with a 20-second silent period between each cry sound. The cries were arranged in two random orders so that each subject heard 16 different cries in one random sequence.followed by the same 16 cries in a second random sequence. Procedure The tape was played to the subjects at a constant volume on a Sony TC-270 stereo tape deck. Adults (naive to the infants' conditions or why they were crying) were instructed to listen to the 10-second cry segment, and during the 20-second silent period, to choose a response that seemed most appropriate for that cry sound from a list of possible caregiving responses. The list of choices included (a) feed, (b) cuddle, (c) pick up, (d) clean, (e) give pacifier, and (f) wait and see. Because the san~e caregiving choice may have different meanings and intents to different listeners, at the end of the 32 trial, the adults were asked to rank (from 1 to 6) the six caregiving responses on two dimensions: (1) "how tender and caring the response is," and (2) "how immediately effective the
ADULT RESPONSESTO CRIESOF LOW AND HIGH RISKINFANTS
171
response is at terminating the crying." Each cry'trial was assigned the ranked score from both dimensions given to the specific response made to the cry'. Thus, the adults created their own ordinal scales along two dimensions for the responses they made to the low- and high-risk infant cries. Scores were separately summed and averaged on each dimension by infant risk group. Because each cry was played twice, a consistency of response score could be generated for the two dimensions. The absolute value of the difference between the scores from the two times each cry was heard was summed and averaged on each dimension by infant risk group.
RESULTS
Table 2 shows the means and standard deviations of the responses made by the adult subjects to the low- and high-risk infant cry sounds. A 2 (Parental Experience) x 2 repeated measure (Infant Risk Group) analysis of variance was performed on each measure. A Parental Experience x Infant Risk Group interaction TABLE 2 Means and Standard Deviations of Adult Responses to Cries from Low and High Risk Infants
Responses Tenderness Parent Non-parent Risk
I Low
3.6
High
2.6
l .95
3.1
I .69
Effectiveness Parent Risk
3.2
[ .88
I Low
3.4
High
2.1
Non-parent 3.1
J .71
.58
I .85
3.2 .82
I .74
Consistencyof
Tenderness Parent Non-parent Low
10.2
Risk High
I248
5.8
13.3
139
12.6
I3-2
I,.2
Effectiwness " Parent Non-parent Low
11.7
Risk
13.0 6.24
High
4.9
J 3.8 11.5
2.8
[ 4.5
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ZESKIND
was found for each measure: "tenderness," F(1.57) = 13.56, p < .001; consistency of "tenderness," F(1,57) = 19.65, p < .001; "eff¢ctiveness," F(1,57) = 23.49, p < .001; and consistency of "effectiveness," F(1,57) = 16.04, p < .001 Newman-Keuls post-hoc comparisons were used to locate the significant differences. For the "tender and caring" dimension, nonparents did not differ in the responses they made to cries from low- and high-risk infants; however, parents gave responses they considered to be more tender and caring to the high-risk than low-risk infant cries (p < .01). Also, parents gave less tender and caring responses than nonparents to cries from low-risk infants (p < .01), but more tender and caring responses than nonparents to cries from high-risk infants (p < .01). The consistency of the responses made on this dimension showed parallel results. Nonparents did not differ in the consistency of their tender and caring responses to cries from low- and high-risk newborns; however, parents were more. consistent in their responses to the high-risk than low-risk infant cries (p < .01). Also, parents were more consistent in their responses than nonparents to the cries from both the low- and high-risk infant's Co's < .01). For the "effectiveness" dimension, nonparents did not differ in their responses made to cries from low- and high-risk newborns; however, parents gave responses they considered to be more effective in terminating the crying to the high-risk than to the low-risk infant cries (p < .01). Although parents and nonparents did not differ in the perceived effectiveness of their responses to low-risk infant cries, parents gave responses they considered more immediately effective in terminating the cries of high-risk infants than nonparents (p < .01). Similarly, in the consistency of the responses on this dimension, nonparents did not differ in their responses to cries from low- and high-risk infants; however, parents were more consistent in their responses to the high-risk than low-risk infant cries (p < .01). Although parents and nonparents did not differ in the consistency of their responses to low-risk infant cries, parents gave more consistent responses than nonparents to the cries of high-risk infants (p < .01). The categorization of each subject's modal response from the six caregiving choices provides a description of the pattern of the caregiving choices selected by parents and nonparents. The six caregiving choices were categorized into three groups according to the functional significance of the two caregiving responses in each group. The categories were: (1) Contact-comfort responses (pick up and cuddle); (2) Utility responses (feed and clean); and (3) Undirected responses (give pacifier and wait and see). Figures 1 and 2 show the number of nonparents and parents who had their modal response in each of the three caregiving categories for the low-risk and high-risk infant cries. The distributions of modal responses to low-risk infant cries were only marginally different for n6nparents and parents, X2 (2) = 5.19, p < .07. The largest number of modal responses for nonparents was in the category of Contact-comfort caregiving, whereas for parents, the largest number of modal responses was in the category of Undirected caregiving. In response to high-risk
ADULT RESPONSESTO CRIES OF LOW AND HIGH RISK INFANTS 25
173
m
20 m
Parents
15
I0
i
m
Contact-comfort
Ut111ty
Responses
Responses
Undirected
Responses
Figure 1. Distribution in three functional categories of modal responsesby parents and nonparents to cries of low-risk infants.
infant cries the distributions of modal caregiving choices were significantly different from nonparents and parents, X 2 (2) = 12.50, p < .01. Whereas responses to high-risk infant cries by nonparents appear to be fairly evenly distributed among the three caregiving categories, 21 of 30 parents gave Contact-comfort kinds of caregiving as modal responses to the cries of high-risk infants while no parent gave an Undirected caregiving choice as their modal response. The number of Utility caregiving choices was similar for both nonparents and parents in response to the cries of blow low- and high-risk infants.
DISCUSSION ;1These results suggest that the cry sounds of infants at risk elicited differential responsiveness from the parents, but not the nonparents in this study. Because parents and nonparents differed in both caregiving experience and age it is difficult to define the factors that account for the differential responsitivity of parents and no~aparents. It is reasonable to speculate, however, that although both experienced and inexperienced caregivers can discriminate the cry sound and are sensitive to its special meaning (Zeskind & Lester, 1978), experience with in-
174
ZESKIND 25 =,.
20 . .
15 i
=
~"
1o -
I
m
! 5 i
Contact-comfort
Utility
Responses
Responses
Undirected
Responses
Figure 2. Distribution in three functional categories of modal responses by parents and nonporents to cries of hlgh-risk infants.
fants may be necessary to translate the differential perceptions into decisive actions. Parents gave responses that paralleled the semantic structures underlying the perceptions of the cries of the risk infant: more "effective" responses to terminate a cry that is more "distressing" and is coming from an infant who is crying for a more "urgent" reason, and more "tender and caring" responses to an infant who sounds " s i c k . " The increased consistency of response to these cries suggests that there is less variability in the meanings attributed by parents to the cries of the risk infant. For no parent was the cry a signal for a modal response of an undirected caregiving choice such as to wait and see or to give a pacifier. Instead, the cry sound was a signal for modal responses that provided contact and comfort such as picking up and cuddling the infant. Thus, even though two infants may be crying for the same reason, the infant at risk may receive more immediate, tender and caring responses from parents. To the extent that the development of the infant at risk is a function of the nature of the caregiving environment (Sameroff & Chandler, 1975; Zeskind & Ramey, 1978), the cry sound of the infant at risk may contribute to the infant's development by influencing caregiver-infant transactions (Zeskind & Lester, 1978). Thus, the cry sound may not only reflect the biological integrity of the
ADULT RESPONSESTO CRIES OF LOW AND HIGH RISK INFANTS
175
infant and how the integrity changes with development, the cry sound may also function as a contributing force behind that developmental process of change. Although some suggest that " . . . if human infants involved the most effective care-eliciting cry, any deviation from the normal cry may be a weaker elicitor of caregiving behavior in adults" (Freudenberg, Driscoll, & Stem, 1978 p. 224), that model of infant crying may not be the most parsimonious explanation of the role of variations in infant cry sounds. Support for that contention is based on the finding that the cries of infants with Down's syndrome were less attention-getting than cries from normal infants. Those results may be, as the authors suggested, specific to the low-pitched cries of the Down's infants they studied. In the present study, for example, high-pitched cries of infants at risk elicited caregiving responses that were both stronger, and more consistent. Another problem is that the concept of what is a normal cry is less than clear. Infants were normal or abnormal, not their cry sounds (Lester & Zeskind, 1979). The frequency of occurrence and the distribution of cry variations in a given population are too uncertain to describe the "normative" nature of specific cry variations. Recent evidence, in fact, suggests that variations such as high pitch may be found in a relatively large percentage of infants in the normal newborn nursery (Lester, in press; Lester & Zeskind, 1978; Zeskind & Lester, 1978; Zeskind, 1979). One can speculate instead that the high-pitched cry characteristic of infants with a wide range of medical conditions is a signal with evolutionarily adaptive qualities (Lester & Zeskind, 1979). For example, high-pitched, pure tonelike sounds emitted by a great many mammals and species of birds function to signal the occurrence of friendly or appeasing engagements in contrast to the lowpitched sounds of hostile encounters (Collias, 1960), and may have adaptive significance when viewed within a model of the evolutionary convergence of motivations and sound structures (Morton, 1977). Not only are high pitched sounds easier to localize, the biological organization of the human listener is particularly responsive to high pitched sounds (Howard, 1973; Masterton & Diamond, 1973). That is, a biological synchrony may exist between the organization of the infant's stressed central nervous system and the organization of the sensory capacities of the listener. In this study we find that prenatal and perinatal conditions that stress the developing central nervous system and create a risk situation for the infant may result in a distinguishable cry sound to which those who will provide care for the infant are particularly sensitive. That the infants in this study were diagnosed as prediatrically healthy implies that the cry sound may signal a need for special care in the absence of other signs. As in the case of the high-pitched cry sounds of an infant who later suddenly died (Stark & Nathanson, 1975), these implications may be particularly relevant. Whereas the diagnostic utility and the social value of the high-pitched cry sound have traditionally been the focus of separate disciplines, a synthesis of views may help in the understanding of the development of the infant at risk.
176
ZESKIND ACKNOWLEDGMENTS
The author would like to thank Craig T. Ramey and Harriet L. Rheingold for early comments in the development of this study. Special thanks and appreciation is due to Barry M. Lester who served as Chairperson of the author's 1976 Master's Thesis (Study I, in Zeskind & Lester, 1978l and whose conceptual and personal, guidance has been a true inspiration.
REFERENCES Bemal, J. Crying during the first ten days of life and the maternal responses. Developmental Medicine and Child Neurology, 1972, 14, 362-372. Collias, N. E. An ecological and functional classification of animal sounds• In W. E. Lanyon & W. N. Tavolga (Eds.), Animal sounds and communication. Washington, D.C.: American Institute of the Biological Sciences, Pub. No. 7, 1960. Formby, D. Maternal recognition of infant's cry. Developmental Medicine and Child Neurology, 1967, 9, 293-298. Freudenberg, R. P., Driscoll, J. W., & Stem, G. S. Reactions of adult humans to cries of normal and abnormal infants. Infant Behavior and Development, 1978, 1, 224-227. Frodi, A., Lamb, M., Leavitt, L., & Donovan, W. Fathers' and mothers' responses to infant smiles and cries. Infant Behavior and Development, 1978, 1(2), 187-198. Frodi, A:, Lamb, M., Leavitt, L. A., Donovan, W. L., Neff, C., & Sherry, D. Fathers' and mothers" responses to the faces and cries of normal and premature infants. Developmental Psychology, 1978, 14(5), 490-498. .Greenberg, M., Rosenberg, I., & Lind, J. First mothers rooming-in with their newborns: Its impact upon the mother. American Journal of Orthopsychiatry, 1973, 43, 783-788. Howard, I. P. The spatial senses. In E. C. Carterette & M. P. Friedman (Eds.), Handbook of perception. New York: Academic Press, 1973. Lester, B. M. A synergistic process approach to the study of prenatal malnutrition. International Journal of Behavioral Development, in press. Lester, B. M., & Zeskind, P. S. Brazelton scale and physical size correlates of neonatal cry features. Infant Behavior and Development, 1978, 1(4), 393-402. Lester, B. M., & Zeskind, P. S. The organization and assessment of crying in the infant at risk. In T. M. Field, A. M. Sostek, S. Goldberg, & H. H. Shuman (Eds.), Infants born at risk. New York: Spectrum, 1979. Masterton, B., & Diamond, I. T. Hearing: Central neural mechanisms. In E. C. Canerette & M. P. Friedman (Eds.), Handbook of perception. New York: Academic Press, 1973. Michelsson, K., Sirvio, P., & Wasz-Hocken, O. Sound spectrographic analysis of infants with bacterial meningitis• Developmental Medicine and Child Neurology, 1977, 19, 309-315. Morton, E. S. On the occurrence and significance of motivation-structural rules in some bird and mammal sounds. American Naturalist, 1977, 111(981), 855-869. Muller, E., Hollien, H., & Marry, T. Perceptual responses to infant crying. Journal of Child Language. 1974, 1, 89-95. Parke, R. D., & Collmer, C. W. Child abuse: An interdisciplinary analysis. In E. M. Hetherington (Ed.), Review of Child Development V. Chicago: University of Chicago Press, 1975. Parmelee, A. H., Kopp, C. B., & Sigman, M. Selection of developmental assessment techniques for infants at risk. Merrill-Palmer Quarterly, 1976, 22 (3), 177-199. Prechtl, H. F. R. The neurological examination of the full-term newborn infant. Clinics in Developmental Medicine, No. 63. Spastics International Medicinal Publications, Philadelphia: J.B. Lippincott Co., 1977.
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Prechtl, H. F. R. Neurological findings in newborn infants after pre- and paranatal complications. In J. Jonix, H. Visser, & J. Troelstra (Eds.), Aspects ofprematurity and dysmat,riO'. Leiden: Stenfert-Kroese, 1968. Prechtl, H. F. R., & Beintema, D. The neurological examination ofthefidl term it~mt. (Clinics in Developmental Medicine, No. 12) London: Hcincmann: Philadelphia: Lippincott, 1964. Sameroff, A., & Chandler, M. J. Reproductive risk and the continuum of carctaking casualty, in F. D. Horowitz (Ed.), Re;,iew of child de~.elopment research (Vol. 4). Chicago: Universtiy of Chicago Press, 1975. Sherman, M. The differentiation of emotional responses in infants. Journal of Comparati~'e Psychology, 1927, 7, 265-284. Stark, R. E., & Nathanson, S. N. Unusual features of cry in an infant dying suddenly and unexpectedly. In J. Bosma & J. Showacre (Eds.), De~,elopment of upper respiratoo" anatomy and function (DHEW Publication No. [NIH] 75-941). Washington, D.C.: Government Printing Office, 1975. Valanne, E., Vuorenkoski, V., Partanen, T., Lind, J., & Wasz-Hockert, O. The ability of human mothers to identify the hunger cry signals of their own newborn infants during the lying-in period. Experientia, 1967, 23, 768. Vaughan, V., & McKay, R. Nelson Textbook of Pediatrics. Philadelphia: W. B. Sanders, 1975. Vuorenkoski, V., Lind, J., Partanen, T., Lejeune, J., Lafourcade, J., & Wasz-Hockert, O. Spectrographic analysis of cries from children with Maladie du Cri ¢1, Chat. Annales Paediatrias Fenniae, 1966, 12, 174-180. Wasz-Hockert, O., Lind, J., Vuorenkoski, V., Partanen, T., & Valanne, E. The infant cry. (Clinics in Developmental Medicine, No. 29) London: Heinemann: Philadelphia: Lippincott, 1968. Wiesenfcld, A. R., & Klorman, R. The mother's psychophysiological reactions to contrasting affective expressions by her own and an unfamiliar infant. De~,elopmental Psychology. 1978, 14 (3), 294-304. Wolff, P. H. The natural history of crying and other vocalizations in infancy. In B. M. Foss (Ed.), Determinants o'finfant behavior. Vol. 4. London: Methucn, 1969. Zcskind, P. S. Fetal nutritional risk and neonatal cry features. Paper presented to the biennial convention of the Society for Research in Child Development, San Francisco, March, 1979. Zeskind, P. S., & Lester, B. M. Acoustic features and auditory perceptions of the cries of newborns with prenatal and perinatal complications. Child Development, 1978, 49 (3), 580-589. Zeskind, P. S., & Ramey, C. T. Fetal malnutrition: An experimental study of its consequences on infant development in two caregiving environments. Child Development, 1978, 49, 11551162.
Adult Responses to Cries of Low and High Risk Infants* PHILIP SANFORD ZESKIND University of North Carolina at Chapel Hill
Thirty parents and 30 nonparents were asked to select on a questionnaire what they considered to be appropriate responsesto taperecorded pain cries elicited from 16 2-day-old infants. Half.of the cries were from healthy, low-risk infants, and half were from healthy infants at high risk due to high numbers of nonoptimal obstetric conditions. The cries from the high-risk infants elicited from parents, but not from nonparents, responsesthat were intended as more "tender and caring" and more "immediately effective at terminating the crying" than the cries from the low-risk infants. Similarly, responses by parents, but not by nonparents, to high-risk infant cries were more consistent than to low-risk infant cries. The classification of modal responsesinto functional categories shawe~dthat 21 of 30 parents gave contact-comfort kinds of responsesto the cries of high-risk infants, while none gave undirected responses. Although the differential cry features characteristic of the high-risk infant have traditionally been used to support the differential diagnosis of central nervious system pathology, these findings we"e interpreted to support a more functional perspective of the cries of the risk infant.
Neonatal crying is a state of arousal associated with characteristic behaviors and sounds (Prechtl, 1977). The nature of the infant's cry sounds are often mentioned in neurological examinations (Prechtl & Beintema, 1964) and in pediatric textbooks (cf. Vaughan & McKay, 1975) as supporting differential clinical evaluations of the medical status of the newborn. Spectrographic analyses have defined differential acoustic features of the cries o f newborn and young infants that have been associated with a wide range o f clinical conditions in which the ~ntcgrity of the infant's developing central nervous system may have been corn*This project was partially supported by NICHHD grant no. 5 TOI HD00424-04 to the Research Training Program of the Frank Porter Graham Child Development Center and by the Biomedical Research Fellowship award to the author from the University of North Carolina at Chapel Hill. Requests for reprints should be addressed to P. S. Zeskind, Department of Pediatrics, School of Medicine, Mailman Center for Child Development, University of Miami, P.O. Box 016820, Miami, Florida, 33101. 167
168
ZESKIND
promised (for a review," see Lester & Zeskind, 1979). For example, a high fundamental frequency (basic pitch) and other spectral and temporal features of the cry differentiate from controls clinically abnormal infants with signs of brain damage (e.g., Vuorenkoski, Lind, Partanen, Lejeune, Lafourcade & WaszHockert, 1968) to healthy infants who show no abnormal physical or neurological signs on routine pediatric examinations yet who may be at risk due to high numbers of nonoptimal obstetric conditions which may stress the developing central nervous system (Zeskind & Lester, 1978). Some evidence suggests that the distinctive cry features disappear with infant recovery, yet remain in the presence of abnormal sequelae (Michelsson, Sirvio & Wasz-Hockert, 1977). Thus, the cry sound may reflect the biological integrity of the infant and how that integrity changes wtih development. In traditionally a separate context, the nature of the cry sound has been studied for its social value. Although the functional effects of the cry of the normal infant have long (e.g., Sherman, 1927) and frequently been examined (Bernal, 1972; Formby, 1967; Frodi, Lamb, Leavitt & Donovan, 1978; Greenberg, Rosenberg, & Lind, 1973; Muller, Hollien & Murry, 1974; Valanne, Vuroenkoski, Partanen, Lind & Wasz-Hockert, 1967; Wasz-Hockert, Lind, Vuroenkoski, Partnaen & Valanne, 1968; Wiesenfeld & Klorman, 1978; Wolff, 1969), the study of the cry of the abnormal and at-risk infant has generally been • limited to its diagnostic utility. Yet the cry of the infant at risk, with the variations in pitch and other cry features, may have functional salience to caregivers as one part of the infant's behavioral repertoire. For example, independent of the sex or parental experience of the adult listner, the unusually low-pitched pain cries of infants with Down's syndrome are considered less unpleasant and convey a less urgent need for attention than pain cries from normal infants (Freudenberg, Driscoll & Stern, 1978). Conversely, the high-pitched cry of a premature infant is considered more aversive and elicits greater autonomic arousal in mothers and fathers than the cry of a full-term infant (Frodi, Lamb, Leavitt, Donovan, Neff & Sherry, 1978). Zeskind and Lester (1978) showed that the high-pitched pain cries of infants with high numbers of nonoptimal obstetric conditions were considered by parents and nonparents of both sexes t ° be more aversive, grating, distressing, sick, urgent, piercing, discomforting, and arousihg than cries of infants with low numbers of these conditions. Factor analysis of all subjects' perceptions showed that although the pain cries of both low- and high-risk infants were perceived along one dimension representing the "distressing" quality of the cry, a second dimension emerged in the perception of the cries of the high-risk infants which conveyed the "sick" and "urgent" nature of the cry sound. Whereas previous work has shown that the cries of the infant at risk may elicit differential attention and perceptions, the goal of this study was to find if, based just on the quality of the cry sound, the cries of the infant at risk signal differential responses and intentions that reflect the underlying perceptual dimensions of the cries. It was hypothesized that adult listeners would choose caregiv-
ADULT RESPONSES TO CRIES OF LOW AND HIGH RISK INFANTS
169
ing responses (on a questionnaire) that were (1) more "immediately effective" in terminating the unpleasant and "distressing" cry of an infant who is crying for an "urgent" reason, and (2) more "tender and caring" for an infant whose cry declares that the infant may be " s i c k . "
METHOD
Subjects Subjects were 30 unmarried college students who reported no professional experience with infants, and 30 parents living in the married student housing section at the same university. The nonparents ranged in age from 18 to 21 years of age (mean age = 18.8) and reported having no children. Parents ranged in age from 21 to 38 years of age (mean age = 29.1) and had 1 to 3 children, none of whom were less than 8 months of age. Half of each group were men and half were women. These subjects represent a separate sample of adults from that of the study of the perceptual dimensions of the cries of risk infants (Zeskind & Lester, 1978).
Stimulus Tape The stimulus tape used in this study is the same as the tape used to examine the perceptual dimensions of the cries of risk infants (Zeskind & Lester, 1978). The stimuli were selected from pain cries elicited and recorded from 24 low-risk and 24 high-risk 2-day-old infants. All infants were full term (range of 37-41 weeks), full birthweight (range of 2750--3960 grams), appropriate weight for gestational age, had both 1- and 5-minute Apgar scores of at least seven, and showed no abnormal signs on neurological and physical examinations. Although the infants showed no signs of abnormality low- and high-risk infants were defined and differentiated by the number of prenatal and perinatal events that may place the infant at risk. To evaluate the number of risk factors, a risk score was constructed using the sum of absent maternal and parturitional optimal obstetric conditions from Prechtl's (1968) scale. Lower scores of optimality (higher nonoptimal scores) resulting from the absence of optimal conditions, have been used as an indicator of the degree of risk to the infant's nervotts system (Prechtl, 1968). Low- and high-risk groups were operationally defined, respectively, as those infants having 2 or less, and 5 or more nonoptimal conditions (Zeskind & Lester, 1978). Table 1 shows the list of obstetric complications found. The groups were balanced for sex and race. A similar procedure of counting the number of obstetric complications based on the absence of Prechtl's optimal conditions has been used to study infants who may be at risk (Parmelee, Kopp & Sigman, 1976).
ZESKiND
170
TABLE 1 List of Obstetric CompJications
MATERNAL FACTORS age (< 18 ol > 30) single marital status parity (> 6) abortion history (> 2) Rh antagonism infection in pregnancy maternal disease edema
toxemia hypertension hypohmsion heart rate irregularities previous C-section cephalo-pelvicdisproportion bleeding during pregnancy low socio-economicstatus
PARTURITIONAL FACTORS multiple birth induced delivery prolonged labor curtailed labor abnormal presentation drugs (other than local anes.)
forceps artificial membranerupture premature membranerupture C-section wrapped cord knot in cord
A cry was elicited by a rubber band snap to the heel of the infant's foot by stretching an Arco No. 64 rubber band 15 cm along the edge of a ruler. The cry was recorded on magnetic tape on a Wollensak model 2520 tape recorder with a Wollensak directional microphone held 20 cm midline from the infant's mouth. A stimulus tape comprised of the first I0 seconds of 8 low-risk and 8 high-risk infant cries randomly selected from these two larger groups was made with a 20-second silent period between each cry sound. The cries were arranged in two random orders so that each subject heard 16 different cries in one random sequence.followed by the same 16 cries in a second random sequence. Procedure The tape was played to the subjects at a constant volume on a Sony TC-270 stereo tape deck. Adults (naive to the infants' conditions or why they were crying) were instructed to listen to the 10-second cry segment, and during the 20-second silent period, to choose a response that seemed most appropriate for that cry sound from a list of possible caregiving responses. The list of choices included (a) feed, (b) cuddle, (c) pick up, (d) clean, (e) give pacifier, and (f) wait and see. Because the san~e caregiving choice may have different meanings and intents to different listeners, at the end of the 32 trial, the adults were asked to rank (from 1 to 6) the six caregiving responses on two dimensions: (1) "how tender and caring the response is," and (2) "how immediately effective the
ADULT RESPONSESTO CRIESOF LOW AND HIGH RISKINFANTS
171
response is at terminating the crying." Each cry'trial was assigned the ranked score from both dimensions given to the specific response made to the cry'. Thus, the adults created their own ordinal scales along two dimensions for the responses they made to the low- and high-risk infant cries. Scores were separately summed and averaged on each dimension by infant risk group. Because each cry was played twice, a consistency of response score could be generated for the two dimensions. The absolute value of the difference between the scores from the two times each cry was heard was summed and averaged on each dimension by infant risk group.
RESULTS
Table 2 shows the means and standard deviations of the responses made by the adult subjects to the low- and high-risk infant cry sounds. A 2 (Parental Experience) x 2 repeated measure (Infant Risk Group) analysis of variance was performed on each measure. A Parental Experience x Infant Risk Group interaction TABLE 2 Means and Standard Deviations of Adult Responses to Cries from Low and High Risk Infants
Responses Tenderness Parent Non-parent Risk
I Low
3.6
High
2.6
l .95
3.1
I .69
Effectiveness Parent Risk
3.2
[ .88
I Low
3.4
High
2.1
Non-parent 3.1
J .71
.58
I .85
3.2 .82
I .74
Consistencyof
Tenderness Parent Non-parent Low
10.2
Risk High
I248
5.8
13.3
139
12.6
I3-2
I,.2
Effectiwness " Parent Non-parent Low
11.7
Risk
13.0 6.24
High
4.9
J 3.8 11.5
2.8
[ 4.5
172
ZESKIND
was found for each measure: "tenderness," F(1.57) = 13.56, p < .001; consistency of "tenderness," F(1,57) = 19.65, p < .001; "eff¢ctiveness," F(1,57) = 23.49, p < .001; and consistency of "effectiveness," F(1,57) = 16.04, p < .001 Newman-Keuls post-hoc comparisons were used to locate the significant differences. For the "tender and caring" dimension, nonparents did not differ in the responses they made to cries from low- and high-risk infants; however, parents gave responses they considered to be more tender and caring to the high-risk than low-risk infant cries (p < .01). Also, parents gave less tender and caring responses than nonparents to cries from low-risk infants (p < .01), but more tender and caring responses than nonparents to cries from high-risk infants (p < .01). The consistency of the responses made on this dimension showed parallel results. Nonparents did not differ in the consistency of their tender and caring responses to cries from low- and high-risk newborns; however, parents were more. consistent in their responses to the high-risk than low-risk infant cries (p < .01). Also, parents were more consistent in their responses than nonparents to the cries from both the low- and high-risk infant's Co's < .01). For the "effectiveness" dimension, nonparents did not differ in their responses made to cries from low- and high-risk newborns; however, parents gave responses they considered to be more effective in terminating the crying to the high-risk than to the low-risk infant cries (p < .01). Although parents and nonparents did not differ in the perceived effectiveness of their responses to low-risk infant cries, parents gave responses they considered more immediately effective in terminating the cries of high-risk infants than nonparents (p < .01). Similarly, in the consistency of the responses on this dimension, nonparents did not differ in their responses to cries from low- and high-risk infants; however, parents were more consistent in their responses to the high-risk than low-risk infant cries (p < .01). Although parents and nonparents did not differ in the consistency of their responses to low-risk infant cries, parents gave more consistent responses than nonparents to the cries of high-risk infants (p < .01). The categorization of each subject's modal response from the six caregiving choices provides a description of the pattern of the caregiving choices selected by parents and nonparents. The six caregiving choices were categorized into three groups according to the functional significance of the two caregiving responses in each group. The categories were: (1) Contact-comfort responses (pick up and cuddle); (2) Utility responses (feed and clean); and (3) Undirected responses (give pacifier and wait and see). Figures 1 and 2 show the number of nonparents and parents who had their modal response in each of the three caregiving categories for the low-risk and high-risk infant cries. The distributions of modal responses to low-risk infant cries were only marginally different for n6nparents and parents, X2 (2) = 5.19, p < .07. The largest number of modal responses for nonparents was in the category of Contact-comfort caregiving, whereas for parents, the largest number of modal responses was in the category of Undirected caregiving. In response to high-risk
ADULT RESPONSESTO CRIES OF LOW AND HIGH RISK INFANTS 25
173
m
20 m
Parents
15
I0
i
m
Contact-comfort
Ut111ty
Responses
Responses
Undirected
Responses
Figure 1. Distribution in three functional categories of modal responsesby parents and nonparents to cries of low-risk infants.
infant cries the distributions of modal caregiving choices were significantly different from nonparents and parents, X 2 (2) = 12.50, p < .01. Whereas responses to high-risk infant cries by nonparents appear to be fairly evenly distributed among the three caregiving categories, 21 of 30 parents gave Contact-comfort kinds of caregiving as modal responses to the cries of high-risk infants while no parent gave an Undirected caregiving choice as their modal response. The number of Utility caregiving choices was similar for both nonparents and parents in response to the cries of blow low- and high-risk infants.
DISCUSSION ;1These results suggest that the cry sounds of infants at risk elicited differential responsiveness from the parents, but not the nonparents in this study. Because parents and nonparents differed in both caregiving experience and age it is difficult to define the factors that account for the differential responsitivity of parents and no~aparents. It is reasonable to speculate, however, that although both experienced and inexperienced caregivers can discriminate the cry sound and are sensitive to its special meaning (Zeskind & Lester, 1978), experience with in-
174
ZESKIND 25 =,.
20 . .
15 i
=
~"
1o -
I
m
! 5 i
Contact-comfort
Utility
Responses
Responses
Undirected
Responses
Figure 2. Distribution in three functional categories of modal responses by parents and nonporents to cries of hlgh-risk infants.
fants may be necessary to translate the differential perceptions into decisive actions. Parents gave responses that paralleled the semantic structures underlying the perceptions of the cries of the risk infant: more "effective" responses to terminate a cry that is more "distressing" and is coming from an infant who is crying for a more "urgent" reason, and more "tender and caring" responses to an infant who sounds " s i c k . " The increased consistency of response to these cries suggests that there is less variability in the meanings attributed by parents to the cries of the risk infant. For no parent was the cry a signal for a modal response of an undirected caregiving choice such as to wait and see or to give a pacifier. Instead, the cry sound was a signal for modal responses that provided contact and comfort such as picking up and cuddling the infant. Thus, even though two infants may be crying for the same reason, the infant at risk may receive more immediate, tender and caring responses from parents. To the extent that the development of the infant at risk is a function of the nature of the caregiving environment (Sameroff & Chandler, 1975; Zeskind & Ramey, 1978), the cry sound of the infant at risk may contribute to the infant's development by influencing caregiver-infant transactions (Zeskind & Lester, 1978). Thus, the cry sound may not only reflect the biological integrity of the
ADULT RESPONSESTO CRIES OF LOW AND HIGH RISK INFANTS
175
infant and how the integrity changes with development, the cry sound may also function as a contributing force behind that developmental process of change. Although some suggest that " . . . if human infants involved the most effective care-eliciting cry, any deviation from the normal cry may be a weaker elicitor of caregiving behavior in adults" (Freudenberg, Driscoll, & Stem, 1978 p. 224), that model of infant crying may not be the most parsimonious explanation of the role of variations in infant cry sounds. Support for that contention is based on the finding that the cries of infants with Down's syndrome were less attention-getting than cries from normal infants. Those results may be, as the authors suggested, specific to the low-pitched cries of the Down's infants they studied. In the present study, for example, high-pitched cries of infants at risk elicited caregiving responses that were both stronger, and more consistent. Another problem is that the concept of what is a normal cry is less than clear. Infants were normal or abnormal, not their cry sounds (Lester & Zeskind, 1979). The frequency of occurrence and the distribution of cry variations in a given population are too uncertain to describe the "normative" nature of specific cry variations. Recent evidence, in fact, suggests that variations such as high pitch may be found in a relatively large percentage of infants in the normal newborn nursery (Lester, in press; Lester & Zeskind, 1978; Zeskind & Lester, 1978; Zeskind, 1979). One can speculate instead that the high-pitched cry characteristic of infants with a wide range of medical conditions is a signal with evolutionarily adaptive qualities (Lester & Zeskind, 1979). For example, high-pitched, pure tonelike sounds emitted by a great many mammals and species of birds function to signal the occurrence of friendly or appeasing engagements in contrast to the lowpitched sounds of hostile encounters (Collias, 1960), and may have adaptive significance when viewed within a model of the evolutionary convergence of motivations and sound structures (Morton, 1977). Not only are high pitched sounds easier to localize, the biological organization of the human listener is particularly responsive to high pitched sounds (Howard, 1973; Masterton & Diamond, 1973). That is, a biological synchrony may exist between the organization of the infant's stressed central nervous system and the organization of the sensory capacities of the listener. In this study we find that prenatal and perinatal conditions that stress the developing central nervous system and create a risk situation for the infant may result in a distinguishable cry sound to which those who will provide care for the infant are particularly sensitive. That the infants in this study were diagnosed as prediatrically healthy implies that the cry sound may signal a need for special care in the absence of other signs. As in the case of the high-pitched cry sounds of an infant who later suddenly died (Stark & Nathanson, 1975), these implications may be particularly relevant. Whereas the diagnostic utility and the social value of the high-pitched cry sound have traditionally been the focus of separate disciplines, a synthesis of views may help in the understanding of the development of the infant at risk.
176
ZESKIND ACKNOWLEDGMENTS
The author would like to thank Craig T. Ramey and Harriet L. Rheingold for early comments in the development of this study. Special thanks and appreciation is due to Barry M. Lester who served as Chairperson of the author's 1976 Master's Thesis (Study I, in Zeskind & Lester, 1978l and whose conceptual and personal, guidance has been a true inspiration.
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