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Differential parental response to familiar and unfamiliar infant distress signals
INFANT BEHAVIOR AND DEVELOPMENT 4, 281-295 (1981)
Differential Parental Response to Familiar and Unfamiliar InfantDistress Signals* ALAN
R.
WIESENFELD, CAROL BANDER MALATESTA AND LINDA L. DELOACH
Douglass College--Rutgers, The State University
Sixteen mothers and sixteen fathers of four- to six-month-old infants listened to the sounds of their own, and an unfamiliar female infant's anger and pain cries, and two tones, as their autonomic responses were monitored. In a second series of stimulus presentations, subjects rated their own subjective feelings with respect to unpleasantness, tension-provocation and novelty of each of the six tapes. For the four infant cry segments, subjects were asked to identify the infant (own or other baby) and the kind of cry expression heard. Mothers reacted to the tapes of their own infant's cries with a brief cardiac deceleration followed by a secondary acceleration, whereas the fathers responded to their own infant's cries with decelerations. Both mothers and fathers responded to the unfamiliar infant's cries and to the tones with heart rate decelerations. The own infant's pain cry was associated with the largest electrodermal response in both parent groups, and mothers rated this cry as the most unpleasant and tension-provoking of the sounds. Mothers and fathers were highly accurate in recognizing their child's cries, but only mothers were able to identify the type of cry accurately. The results are discussed in terms of orienting and defensive response patterns and the differential Caregiving experiences of mothers and fathers.
Traditional assumptions about dimorphism in parental behavior have included the notions that women are more suited to child rearing because of *Portions of this report were presented at the meetings of the Society for Research in Child Development, San Francisco, 1979. This research was supported in part by Rutgers University Research Council Grant//07-2208 to the first author. We would like to thank Joseph Campos, Jeanette Haviland, Carolyn Royce-Collier, Michael Lewis and Edith Neimark for. their comments. We also acknowledge contributions to the research by Robert Edelberg, Peter Fried, Allen Jusko, Rafael Klorman, Richard Lore, Stephen Potter, Dave Thomas and the Edward R. Johnstone Training and Research Center. Requests for reprints should be sent to Alan R. Wiesenfeld, Department of Psychology, Douglass College, New Brunswick, l~ew Jersey 08903.
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their biological connectedness with offspring, that they are innately more interested in children and are more talented nurturers than men. Recently, these assumptions have been subject to critical evaluation. Several recent studies have indicated that fathers'may be as talented in caregiving as mothers. Although Thomas, Franks and Calonica (1972) reported that fathers were less supportive and warm towards their children than mothers, Parke and Sawin (1977) failed to confirm this finding. In other studies (Parke & O'Leary, 1976) where fathers and mothers were observed in interaction with their infants, fathers were as affectionate, responsive and active as mothers. In addition, Greenberg and Morris (1974) reported that fathers are just as absorbed in their infants as mothers. Infants, for their part, do not display clear preferences for the mother over the father, at least in measures of attachment elicited during separation (Parke, 1978). However, the nature of the bond between mothers and infants and fathers and infants may be mediated by different factors: Mothers provide more physical caregiving, whereas fathers engage in more play-related activities (Lamb, 1975; Lewis & Weinraub, 1976). Since sensitivity to infant signals has been linked to attachment (Ainsworth, 1969, 1972) and to good mother-infant rapport (Ainsworth, 1972; Bell & Ainsworth, 1972; Field, 1977; Donovan & Leavitt, 1980), and is presumably intrinsic to the provision of an optimal social environment for the developing infant, the question of possible mother-father sensitivity differences is an important one. In light of the qualitative difference in the types of interactions mothers and fathers display when playing or providing physical caregiving, and because most early infant signals appear to promote caregiver proximity for immediate physical needs (Bowlby, 1969), it is reasonable to anticipate that fathers may be less receptive and responsive to some of the signals of young infants. It is also possible that fathers selectively respond to signals inviting play (i.e., smiles) and not to those signaling the need for immediate physical caregiving (i.e., cries). Two recent studies of mothers' and fathers' responsivity to videotapes of smiling and crying infants (Frodi, Lamb, Leavitt & Donovan, 1978a; 1978b) failed to support the notion of differential sensitivity based on parental roles. Although autonomic responses to smiles and cries differed, the pattern of responses of mothers and fathers did not. However, the videotaped sequences used in both studies were only of infants unfamiliar to the parents. Ainsworth has defined attachment as "an affectional tie or bond that one individual.., forms between himself and another specific individual" (1972, p. 100); in addition, the unique aspects of the parents' own infant's signals may be a product of the infant's and caregivers' extensive interaction (Brazelton, Koslowski & Main, 1974). These considerations lead one to question the generality of findings based upon response to the signals
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of an unfamiliar child. In fact, mothers' autonomic responses to videotapes of the smiles and cries of their own versus an unfamiliar infant have recently been reported to differ markedly (Wiesenfeld & Klorman, 1978). The present investigation was designed to examine the specificity of parental response to familiar and unfamiliar infants by recording parents' autonomic and subjective responses to their own and an unfamiliar infant's distress vocalizations. The methodology of this study differs from those of Frodi et al. (1978a, b) in several ways: Responses to both unfamiliar and familiar children's signals were assessed, and the signals took the form of 15-sec audiotapes as opposed to 2-rain videotapes. In addition, a comparison was made between the parents' autonomic responses to the onset of the auditory stimuli against a pink noise background, whereas earlier studies assessed responses to the change in the infant's state from quiescent to distressed. It was hypothesized that parental responses to the parent's own infant would differ from responses to the unfamiliar infant and, moreover, that mothers and fathers would show differing patterns of response to the cries of their own infant.
METHOD Subjects The subjects were 16 mothers ( X age = 29.7 years, S.D. = 4.2) and 16 fathers (X age = 31.5 years, S.D. = 4.7) recruited through local pediatricians and published notes. All subjects and their infants (X = 153.6 days, S.D. = 23.2) were in good health and denied the use of medication. Psychological testing of mothers was not carried out within 3 days preceding or following the menses. All subjects had volunteered to participate in a study of infant-parent communication and agreed to listen to tape recordings of the vocalizations of their own and other same-aged infants as physiological measures were monitored. Prior to participation in the experiment, mothers were informed that during the first experimental session tape recordings of their infant's sounds, including crying, would be obtained. Upon arrival at the laboratory, mothers signed a consent form specifying the details of psychophysiological recording and initialed an information sheet which described the specific procedures employed in "eliciting the infant vocalizations. The mothers were informed during this first session that, upon returning for participation in the psychophysiological recording session, they would hear segments of tapes of their own child and those of another infant.
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Stimuli There were four variants of 15-see audiotapes of infant cries. Two of these were recordings of the subject's own infant, and the other two of a 5-month-old female unfamiliar to the subject. These four segments included one episode of each infant's anger cry (produced by physical restraint or the repeated withdrawal of a pacifier) and another of each infant's pain cry (produced by a rubber hand snap to the heel). Two additional 15-see taped sequences of 400 Hz and 100Hz pure tones with uncontrolled rise times were included as affectively neutral control stimuli. Each of the six tape-recorded segments was presented at a peak level of 80dB (SPL) and played in three consecutive trials. The unfamiliar infant cries used in this study were selected by experienced listeners as representative of five-month-old infant cries. As a further check on the representativeness of the stimuli, the following data were collected: Anger cries of ten of the infants (including the tape used as the "unfamiliar infant" cry) were selected randomly from the pool of cries used in the study and arranged in two different random orders. Thirteen mothers listened to these tapes arranged in one order; thirteen heard a second random order. Subjects first listened to the 10 cries and then, after the cries were played individually, the subject rated each cry's degree of unusualness on a scale of 0-100. Results for the two stimulus orders did not differ and so were combined in the following descriptions. A mean usualness rating for each of the ten cries was calculated, and the cries rank ordered from most unusual sounding (#1) to least (#10). The unfamiliar infant cry ranked eighth of the ten cries, confirming the earlier judgment that this infant's cries were quite usual sounding with respect to mothers' judgments and, hence, a fair representation of the cries of a five-month-old infant. Characteristics of the Cry Stimuli. Spectrographic analysis of the recorded cry stimuli were performed by means of a Kay model 7029A Spectrum Analyzer, and each cry scored for mean peak fundamental frequency and for duration of the first cry expiration. Tapes of anger cries were edited such that each stimulus segment began with a burst of rhythmical crying, a pattern consistent with Wolff's (1969) description of the " m a d " cry. Spectral analyses indicated that the mean fundamental frequency (F~i) of the cries elicited by pacifier removal was 418.74Hz (S.D. = 55.4), and by restraint 455.0H (S.D. = 84. I). These latter two values did not significantly differ with respect to F~ (t(22) = .82; n.s.). The mean duration of the first expiration o f the anger cries was .94 sec (S.D. = .50); the mean duration of the first expirations evoked by pacifier removal and restraint were 0.71 sec (S.D. = .62) and 0.99 sec (S.D. = .50), respectively; (t(22) = 1.01; n.s.). Pain cry tapes were edited to include the first 15 sec following the pain
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stimulus. Spectral analyses of the pain vocalizations indicated that the mean peak F¢ ranged from 225 to 850Hz (X = 539"1Hz, S.D. = 116.7) and the mean duration of the first cry expiration was 0.59 sec (S.D. = .67). Order. The six auditory stimuli were presented in four different orders to control for possible sequence effects. The first and fourth segments of each stimulus series were always tones, and the remaining four segments the subject's own and the unfamiliar infant's cries. The two episodes of the subject's own infant were played in succession, with order of anger and pain episodes reversed over halves of the sample. Similar counterbalancing was employed for episodes involving the unfamiliar infant.
Procedure
First Session. Upon arrival at the laboratory, the mother and infant were separated and the mother escorted to another room, where she completed a questionnaire concerning infant characteristics. The infant was seated in a high chair in preparation for tape recording. When the infant was alert and calm, the anger cry was elicited by allowing the infant to suck for 10 sec on a sucrose-coated pacifier which was then quickly taken from the infant's mouth. This procedure was repeated up to a maximum of six times, unless the infant began to cry before then. If this procedure failed to produce a cry, the child's arm and leg movements were restrained by a female experimenter who avoided eye contact with the child. After this anger cry was recorded, the infant was picked up and soothed by the female experimenter and then returned to the high chair. The pain cry was then elicited by gently snapping the heel of the infant's foot with a 6-mm-wide rubber band stretched to 7 cm. Infant vocalizations were recorded on magnetic tape by a Revox model A-77 recorder and a Superscope model EC-35 condenser microphone placed 0.5 m from the infant's mouth. Upon completion of this procedure, the infant was soothed and returned to his/her mother. Second Session. Mothers and fathers were tested individually. Upon arrival at the laboratory, each parent was given a brief explanation of psychophysiological recording and asked a series of questions concerning her/his health and recent medical history. A female experimenter then attached standard Beckman Biopotential electrodes to the medial phalanges of the index and middle fingers of the parent's nonpreferred hand. These electrodes, which served to record skin conductance, were filled with Unibase saline solution (Lykken & Venables, 1971) and secured with electrode collars and surgical tape. In addition, the experimenter attached two Beckman
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M i n i a t u r e Biopotential electrodes below the rib cage, for detecting the electrocardiogram. A Grass E34DS silver earclip was attached to the left ear to serve as a ground, hnd a mercury-filled strain gauge taped to the parent's upper chest to record respiratory cycles. The parent was then seated in a recliner chair and the r o o m lights dimmed. After a 10-min habituation period, a set of standard instructions was read over an intercom advising the parent that she/he was about to hear several brief tape-recorded segments of tones and the vocalizations o f her/his own infant and of another infant. The stimuli were played through a KLH model 31 loudspeaker positioned 2.6 m in front o f the parent's chair. Following the procedures, the six varieties o f tape-recorded segments were played in the same order played earlier, and the parent was asked to rate, on a 10-point scale, each segment for its pleasantness (1 = very pleasant; 10 = very unpleasant), his/her tension experienced during the segment (1 = extremely relaxed; 10 = tense as I've ever been), and its novelty (1 = extremely ordinary; 10 = extremely unusual). For the four segments involving cries, the subject was asked to identify the infant (own versus mother's infant) and the kind o f cry (pain, anger or other).
Measurement and Scoring of Physiological Activity. Physiological measures were recorded by a Grass model 5C polygraph. Skin conductance was recorded by means o f constant voltage circuit with a maximum sensitivity of .01/~mho/mm and skin conductance level scored with regard to the level at the onset o f each stimulus, and skin conductance response defined as the maximum amplitude change from the initial level during the 15-sec exposure to a recorded segment. The electrocardiogram was transduced by an electronic cardiotachometer into heart rate in beats/min. These data were scored by hand for each trial, for 1 sec prior to stimulus onset (baseline) and for 15 sec following stimulus onset, with a correction for cardiotachometer lag. The first cardiac cycle completed after the onset o f the stimulus was assigned as a pre- or post-stimulus beat, depending upon whether more than one half o f the cycle occurred before or after stimulus onset. The cardiotachometer (beat by beat) data were converted into average heart rate, weighted by the portion o f the second in which it occurred, in a manner consistent with Graham's (1978) recommendations for measuring heart rate through real time periods. RESULTS All physiological data were subjected to analyses o f variance, with Stimulus Order (4) and Parental Group (2) as between-subjects factors and Stimulus Types (6), Trials (3), and Seconds (7) as within-subjects factors. For the
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heart rate data, linear, quadratic and cubic trends of Trials and Seconds were evaluated. Because the analyses failed to .disclose any Stimulus Order effects, this factor was not considered in any subsequent analyses. Cardiac Rate
An analysis of variance of heart rates during the prestimulus sec indicated that comparable baseline levels preceded the six episodes: F(5, 150) ( I, n.s. An overall analysis of variance of the heart rates during the prestimulus sec and first six sec after stimulus onset yielded a significant interaction of stimulus Types and Seconds: F(30, 900) = 2.28, p ( .001. Therefore, tests for simple effects of the interaction were performed by separate analyses of variance and trend analyses, to assess the waveform of cardiac response to each of the six stimulus categories. These analyses were performed on the heart rates during the prestimulus sec and the first six sec after stimulus onset. Because heart rate reactions to their own child's pain cry and 400Hz tone changed over trials, comparisons between the conditions and groups were based on the initial trial only. Cardiac responses to the first trial of their own infant's cries and the unfamiliar child's cries are plotted in Figure I. The data are expressed as mean differences from the prestimulus values. The responses to the two cry segments (pain and anger) from the subject's own infant were characterized by comparable waveforms within each parental group (Types x Seconds, F(1, 12) = 2.19, n.s.).'Hence, the reactions to these two segments were averaged in subsequent comparisons. Similarly, the two unfamiliar infant cries evoked reactions which did not differ from each other (Types x Seconds, F(1, 12) = 4.12, n.s.) and were also combined for comparison. Finally, the two neutral-tone episodes failed to elicit significantly different reactions for either parental group and were combined for the following comparisons. The cries of the mothers' own infant elicited an initial deceleration lasting about 2 sec, followed by an acceleratory change which peaked between the fourth and fifth sec after stimulus onset. The acceleratory trend is reflected in linear, F(1, 12) = 12.93, p ( .004, and cubic, F(1, 12) = 18.93, p ( .001, components of seconds. In contrast, the fathers' cardiac response to their own child's cries was characterized by slight initial tachycardia, a secondary deceleration, and subsequent return to baseline. The cubic component of seconds approached significance, F(1, 12) = 4.67, p ( .052. When mothers' and fathers' cardiac responses to their own child's cries were compared, a marked difference in the cubic trend of second emerged, accounted for by the sharply accelerating limb of the mother's response (Seconds cubic x Group, F(1, 30) = 7.88, p (.009), which was not evident in the fathers' response. In response to the sound of the unfamiliar child's
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UNFA MILIA R CHILD'S CRIES
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Figure 1. Mothers' and fathers' cardiac responses to the initial trials of their own child's and an unfamiliar child's cries,
two cries, mothers' heart rates showed a deceleratory trend over the first six • seconds after stimulus onset. The cubic trend of Seconds was significant, F(I, 12) = 9.94, p < .008. The fathers' reaction to the unfamiliar cries was also in the direction of deceleration, but only approached statistical significance, Seconds quadratic, F(1, 12) = 4.12, p ( . 0 6 5 . A comparison of mothers' and fathers' responses to the unfamiliar cries indicated comparable pattems of cardiac change. (All trends of Seconds x Group, F(1, 30) ( I, n.s.). Analysis of cardiac responses to the neutral tones disclosed a nonsignificant biphasic change for mothers (Seconds cubic, F(1, 12) = 4.41, p (.06) and a significant deceleratory response in the fathers Seconds quadratic, F(1, 12) = 10.09, p (.008; Seconds cubic, F1, 12) = 5.81, p < .04). A comparison of mothers' and fathers' responses to the tones indicated that the fathers' bradycardia was more pronounced (Seconds quadratic x Group, F(I, 30) = 8.40, p (.007). Skin C o n d u c t a n c e
Analysis of variance conducted on the baseline skin conductance levels preceding each trial of each stimulus type failed to disclose differences between the arousal levels of the two parental groups, F(1, 30) = 2.77, n.s. Analysis of variance of the skin conductance response values revealed a significant difference in magnitude of response among the six stimulus types, F(5, 150) = 2.63, p ( .026. However, nq difference in response magnitude was found
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Figure 2. Mothers' and fathers' electrodermal responses to the pain and anger cries of their own child and to the cries of the unfamiliar infant.
between the mothers and fathers (Types x Group F(5, 150) < 1, n.s.). Comparisons between the stimulus types were performed on the means of the three trials of each type for the combined mothers' and fathers' data by means of Neumann-Keuls tests with a probability level set at .05. These data are displayed in Figure 2. A pairwise test of the means indicated tl~at the parents' skin conductance response to their own baby's pain cry exceeded l:eactions to all other types 6o .01). Skin conductance responses to the other five stimulus types did not differ.
Subjective Responses Table 1 depicts the parents' subjective ratings of the six stimulus types.
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TABLE 1 Mothers' and Fathers' Subjective Ratings of the Stimuli
Stimulus Type:
Own Anger Pain
Unfamiliar Anger Pain
Tone 400Hz lO00Hz
Mothers PleasantnessUnpleasantness Tension Novelty
7.25 7.25 3.69
8.56 8.38 4.81
6.50 5.81 4.88
6.88 6.25 4.38
5.25 4.06 5.06
5.18 4.75 4.69
Fathers PleasantnessUnpleasantness Tension Novelty
6.06 5.06 3.75
7.19 6.31 4.50
6.13 4.88 4.63
6.50 5.69 4.56
5.88 4.69 5.31
5.38 3.69 5.44
Analysis of variance of the ratings of pleasantness-unpleasantness revealed significant differences among the types (F(5, 150) = 16.73, p ~ .001), but there were no mother versus father group differences in pattern or magnitude of these ratings (F(1, 30) = 1.19, n.s.). As examination of Table 1 illustrates, mothers rated the sound of their own child's pain cry to be more unpleasant than any of the other types. Pairwise tests indicated that the mothers' rating of the unpleasantness of this cry was.significantly greater than their ratings of the unfamiliar child's anger cry and that it exceeded fathers' ratings of unpleasantness for both unfamiliar cries (p (.05), but not the fathers' rating of the familiar child's pain cry. The mothers rated their own child's anger cry as next most unpleasant; however, this rating did not differ statistically from their ratings, nor from fathers' unpleasantness ratings, of the two unfamiliar cries. Analysis of variance of the ratings of subjective tension experienced during the stimulus episodes revealed a mother versus father group difference (F(1, 30) = 4.52, p (.042) and differences among the Stimulus Types (F(5, 150) = 20.61, p (.001). According to the Neumann-Keuls test, mothers' ratings of their level of tension during the episode of their own child's pain cry was greatest, higher than all of'the other mother and father ratings of tension except for mothers' rating of tension during their own child's anger cry (p (.05). Mothers also rated their own child's anger cry as more tension-producing than the 1000Hz tone. Analysis o.f variance of the novelty ratings yielded an effect for Stimulus Types (F(5, 150) = 3.0, p ( . 0 2 ) . The tones were rated as most unusual, with ratings for the 400Hz tone exceeding the two own child's cries and the unfamiliar infant's pain cry. The unfamiliar infant's anger cry was judged
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to be more unusual than the own child's anger cry, and the own child's pain cry more unusual than the own child's anger, cry (p ( . 0 5 ) . Finally, the sound of the unfamiliar infant's pain cry was judged to be more unusual than the own child's anger cry.
Recognition Accuracy One- and two-sample proportion tests were employed to analyze the identification data (Freund, 1973; Anderson & Sclove, 1978). Mothers were able to correctly identify the sounds of their own infants 97070 of the time, fathers 84070 of the time. Mothers were able to correctly identify the sounds of another infant as unfamiliar (i.e., not their own child) 75070 of the time, fathers 44°70 of the time. The combined overall recognition accuracy was thus 86°70 for mothers and 64°70 for fathers; both groups' rates exceeded the chance level of 50070 (p < .001, a n d p < .01, respectively). Incorrect identifications were divided between relatively few of their own infants' cries misidentified as belonging to another infant (3070 for mothers, 1607o for fathers), and relatively greater numbers of unfamiliar cries, misidentified as belonging to the subject's own infant (25°7o for mothers, 56070 for fathers). TABLE 2 Number and Percent (in Parentheses) Correct Identification of Type of Cry of Own and Unfamiliar Infant By Mothers and Fathers (n = 16 for each cell)
Pain Infant Own Unfamiliar
Anger
Mothers
Fathers
Mothers
Fathers
8 (50) 4 (25)
6 (38) 5 (31)
13 (81) 10 (63)
8 (50) 8 (50)
Table 2 displays the parents' judgments of the type of cry heard in terms of percentages of correct judgments plotted by the actual identity of the stimulus infant and type of cry played (pain yersus anger). The overall accuracy of mothers was 55070, a rate Significantly better than a chance level of .33 (z = 3.78, p ( . 0 1 ) given the three choices of anger, pain or other; the corresponding rate for fathers was 42070, which did not exceed the chance level (z = 1'.56,p (.06). The percentage of mothers' correct judgments when listening to their own child's sounds (pain and anger combined) was 65.5070, significantly better than chance (p ( . 0 1 ) . The corresponding rate for fathers (42070) was not greater than chance (p (.01). The percentages of cot-
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WIESENFELD, MALATESTA AND DELOACH
rect cry-type judgments for unfamiliar infant cries (pain and anger combined) were 44°7o and 41 070, for mothers and fathers respectively; in neither case was this percentage different from the chance level. A comparison of mothers' accuracy scores t'or their own infant (65.507o) and for unfamiliar infant cries (44070) revealed that mothers were significantly more accurate in differentiating among the cries of their own child (p ( . 0 5 ) . For fathers, however, a similar comparison of accuracy scores for own versus unfamiliar cries was not significant, indicating that the fathers were not able to better discriminate among the various sounds of their own child. DISCUSSION The results indicate that mothers and fathers differ in their autonomic responsiveness to their own infant's distress signals. Mothers exhibited cardiac response patterns consistent with a defensive reaction (i.e., tachycardia) when listening to their own child's cries, whereas fathers responded with a marginally significant cardiac deceleration, a pattern consistent with the orienting response. Differential experience with and exposure t o the infant may underlie these differences in responsiveness, as well as different role behaviors which largely assign the tasks of physical caregiving to mothers. Because it is typically the mother, rather than the father, who takes responsibility for soothing her distressed infant, the maternal pattern of response observed in the present investigation may reflect a pattern described by Obrist (1976) as active coping, whereas the paternal pattern may be more consistent with a passive coping process in the face of the infant's distress signals. This possibility was supported by the anecdotal accounts of our research subjects; many of the mothers reported that they seemed less able to ignore their child's cries than their spouses. In terms of responsiveness to an unfamiliar infant's distress signals, mothers and fathers autonomic response patterns were comparable. This finding is consistent with the earlier reports of Frodi et al. (1978a, 1978b). However, the response pattern associated with the unfamiliar child's cries was of cardiac deceleration, or an orienting response. The orienting pattern may relate to the slightly greater novelty of the cries in comparison to one's own child's sounds, or, alternatively, to a more passive attitude on the part of mothers listening to another child in distress. The subjective response data indicate that mothers find the cries of unfamiliar children moderately aversive, yet the defensive response pattern did not emerge. Perhaps cultural values constraining unrelated adults from "interfering" with another person's child may belie the observed own-versus-unfamiliar child response patterns in mothers. No differences in cardiac responsiveness to the pain-versus-anger vocalizations were observed in either parental group. Interestingly, the pain
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vocalizations of the parent's own child evoked the largest electrDdermal responses for both parent groups. Perhaps this latter measure is more sensitive to the heightened aversiveness of this kind of distress signal. The subjective ratings support the notion that pain crying is especially unpleasant to parents, especially mothers. The results indicate that mothers' reactions to their own and unfamiliar infants are not equivalent. However, the question remains: Is one's own infant's cry especially unpleasant because it is more difficult to ignore and, therefore, more noxious and aversive, or is it more unpleasant because it tends to arouse similar emotions in the caregiver through an empathic process? Wiesenfeld and Malatesta (in press) have suggested that mothers respond to their infant's cries because the infant's distress touches an "empathic core." Some workers (Frodi eta!., 1978b; Lamb, 1978) have stressed the aversive properties of the cry, and have suggested that caregivers respond to crying in order to terminate aversive stimulation. Whatever the case, the results of the present study confirm that mothers experience their own child's distress as especially unpleasant. Mothers were more accurate in reqognizing their own child's cries and in differentiating among cry types thari fathers. Perhaps this phenomenon reflects the mother's greater experience in soothing the child. The results of the present study contrast with those of Frodi et al. (1978a, 1978b) in two ways. In the Frodi et al. studies, it was concluded that mothers and fathers physiological responsiveness to infant signals did not differ. In the present study it was found that differences did indeed exist, but only with respect to responsiveness to one's own child's signals. Frodi et al. described the general reaction of parents to crying infants to include cardiac acceleration, whereas our results suggest that parental response to unfamiliar infant crying is associated with heart rate deceleration. Perhaps this difference in the direction of change between the two laboratories results from the basic methodological differences described in the Introduction. The differential maternal response to own-versus-unfamiliar infant's signals found in thepresent study illustrates that adult responsivity to infant signals may vary with relatedness to the infant. It is highly likely that the signals ~of one's own offspring comprise a set of signals with unique meaning. As such, future experimental stuclies of parental response to infants should include the parent's own child's signals as stimuli. t
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Anderson, T. W., & Sciove, S. L.: An introduction to statistical analysis of data. Boston: Houghton Mifflin Co., 1978. Bates, J. E., Bennetti C. A., & Lounsbury, M. L. Temperamental difficuitness in infants: correlates of maternal'perceptions. Paper presented at t.he m.eeting of the International Conference on Infancy Studies, Providence, R.I., March 1978. Bell, S. M., & Ainsworth, M. D. S. Infant crying and maternal responsiveness. Child Development, 1972, #3, 1171-1190. Bowlby, J. Attachment and loss (Vol. 1: Attachment.) London: Hogarth Press and the Institute of Psycho-Analysis, 1969. Brazelton, T. B., Koslowski, B., & Main, M. The origins of re~ciprocity: The early motherinfant interaction. In M. Lewis & L. Rosenblum (Eds.), The effect of the infant on its caregiver. New York: John Wiley and Sons, 1974. Donovan, W. L., & Leavitt, L. A. Early cognitive development and its relation to maternal physiological and behavioral responsiveness. Child Development, in press. Field, T. Maternal stimulation during infant feeding. Developmental Psychology, 1977, 13, 539-540.
Freund, J. E. Modern elementary statistics. Englewood Cliffs, N.J.: Prentice-Hall, 1973. Frodi, A. M., & Lamb, M. E. Psychophysiologicalresponse to infant signals in abusive mothers and mothers of premature infants. Paper presented at the meeting of the Society for Psychophysi.ological Research, Madison, Wis., September 1978. Frodi, A. M., Lamb, M. E., Leavitt, L. A., & Donovan, W. L. Fathers' and mothers' responses tO infant smiles and cries. Infant Behavior and Development, 1978b, 1, 187-198. Frodi, A. M., Lamb, M. E., 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, 1978a, 14~ 490-498. Graham, F. K. Co~straints on measuring heart rate and period sequentially through real and cardiac time. Psychophysiology, 1978, 15, 492-495. (3reenberg, M., & Morris, N. Engrossment: "I~henewborn's impact upon the father. American Journal of Orthopsychiatry, 1974, 44, [520-531. . Lamb, M. E. Fathers: Forgotten contributor's to child deVelopment. Human Development, 1975, 18, 245-266. i Lamb, M. E. The influence of the child on marital quality and family interaction during the prenatal, paranatal and infancy periods. In R. M. Lerner & (3. B. Spanier (Eds.), Child influence on marital and family interaction: A lifespan perspective. New York: Academic, 1978. Lewis, M., & Weinraub, M. The father's role in the infant's social network. In M. E. Lamb (Ed.), The role of the father in child development. New York~-'John Wiley and Sons, 1976. Lykken, D. T., & Venables, P. H. Direct measurement of skin conductance: A proposal for standardization. Psychophysiology, 1971, 8, 656-672. Obrist, P. A. The cardiovascular-behavioral interactions--as it appears today. Psychophysiology, 1976, 13, 95-107. Parke, R. D. Perspectives on father-infant interaction. In J. D. Osofsky (Ed.), Handbook of infancy. New York: John Wiley and Sons, 1978. Parke, R. D., & O'Leary, S. Family interaction in the newborn period: Some findings, some observations, and some unresolved issues. In K. Riegel & J. Meacham (Eds.), The developing individual in a changing world: Social and environmental issues. The Hague: Mouton, 1976. Thomas, D. L., Franks, D. D., & Calonica, J. J. Role taking and power in social psychology. American Sociological Review, 1972, 37, 605-614.
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Wiesenfeld, A. R., & Klorman, R. The mother's psychophysiological reactions to contrasting expressions by her own and an unfamiliar infant. Developmental Psychology, 1978, 14, 294-304. Wiesenfeld, A. R., & Malatesta, C. Z. Infant distress: Variables affecting responses of caregivers and others. In R. Gandleman & L. Hoffman (Eds.), Parental behavior: Its causes and consequences. Hillsdale, N.J.: Lawrence Eribaum Associates, in press. Wolff, P. H. The natural history of crying and other vocalizations in early infancy. In B. M. Foss (Ed.), Determinants o f infant behavior IV. London: Methuen, 1969.
Differential Parental Response to Familiar and Unfamiliar InfantDistress Signals* ALAN
R.
WIESENFELD, CAROL BANDER MALATESTA AND LINDA L. DELOACH
Douglass College--Rutgers, The State University
Sixteen mothers and sixteen fathers of four- to six-month-old infants listened to the sounds of their own, and an unfamiliar female infant's anger and pain cries, and two tones, as their autonomic responses were monitored. In a second series of stimulus presentations, subjects rated their own subjective feelings with respect to unpleasantness, tension-provocation and novelty of each of the six tapes. For the four infant cry segments, subjects were asked to identify the infant (own or other baby) and the kind of cry expression heard. Mothers reacted to the tapes of their own infant's cries with a brief cardiac deceleration followed by a secondary acceleration, whereas the fathers responded to their own infant's cries with decelerations. Both mothers and fathers responded to the unfamiliar infant's cries and to the tones with heart rate decelerations. The own infant's pain cry was associated with the largest electrodermal response in both parent groups, and mothers rated this cry as the most unpleasant and tension-provoking of the sounds. Mothers and fathers were highly accurate in recognizing their child's cries, but only mothers were able to identify the type of cry accurately. The results are discussed in terms of orienting and defensive response patterns and the differential Caregiving experiences of mothers and fathers.
Traditional assumptions about dimorphism in parental behavior have included the notions that women are more suited to child rearing because of *Portions of this report were presented at the meetings of the Society for Research in Child Development, San Francisco, 1979. This research was supported in part by Rutgers University Research Council Grant//07-2208 to the first author. We would like to thank Joseph Campos, Jeanette Haviland, Carolyn Royce-Collier, Michael Lewis and Edith Neimark for. their comments. We also acknowledge contributions to the research by Robert Edelberg, Peter Fried, Allen Jusko, Rafael Klorman, Richard Lore, Stephen Potter, Dave Thomas and the Edward R. Johnstone Training and Research Center. Requests for reprints should be sent to Alan R. Wiesenfeld, Department of Psychology, Douglass College, New Brunswick, l~ew Jersey 08903.
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WIESENFELD, MALATESTA AND DELOACH
their biological connectedness with offspring, that they are innately more interested in children and are more talented nurturers than men. Recently, these assumptions have been subject to critical evaluation. Several recent studies have indicated that fathers'may be as talented in caregiving as mothers. Although Thomas, Franks and Calonica (1972) reported that fathers were less supportive and warm towards their children than mothers, Parke and Sawin (1977) failed to confirm this finding. In other studies (Parke & O'Leary, 1976) where fathers and mothers were observed in interaction with their infants, fathers were as affectionate, responsive and active as mothers. In addition, Greenberg and Morris (1974) reported that fathers are just as absorbed in their infants as mothers. Infants, for their part, do not display clear preferences for the mother over the father, at least in measures of attachment elicited during separation (Parke, 1978). However, the nature of the bond between mothers and infants and fathers and infants may be mediated by different factors: Mothers provide more physical caregiving, whereas fathers engage in more play-related activities (Lamb, 1975; Lewis & Weinraub, 1976). Since sensitivity to infant signals has been linked to attachment (Ainsworth, 1969, 1972) and to good mother-infant rapport (Ainsworth, 1972; Bell & Ainsworth, 1972; Field, 1977; Donovan & Leavitt, 1980), and is presumably intrinsic to the provision of an optimal social environment for the developing infant, the question of possible mother-father sensitivity differences is an important one. In light of the qualitative difference in the types of interactions mothers and fathers display when playing or providing physical caregiving, and because most early infant signals appear to promote caregiver proximity for immediate physical needs (Bowlby, 1969), it is reasonable to anticipate that fathers may be less receptive and responsive to some of the signals of young infants. It is also possible that fathers selectively respond to signals inviting play (i.e., smiles) and not to those signaling the need for immediate physical caregiving (i.e., cries). Two recent studies of mothers' and fathers' responsivity to videotapes of smiling and crying infants (Frodi, Lamb, Leavitt & Donovan, 1978a; 1978b) failed to support the notion of differential sensitivity based on parental roles. Although autonomic responses to smiles and cries differed, the pattern of responses of mothers and fathers did not. However, the videotaped sequences used in both studies were only of infants unfamiliar to the parents. Ainsworth has defined attachment as "an affectional tie or bond that one individual.., forms between himself and another specific individual" (1972, p. 100); in addition, the unique aspects of the parents' own infant's signals may be a product of the infant's and caregivers' extensive interaction (Brazelton, Koslowski & Main, 1974). These considerations lead one to question the generality of findings based upon response to the signals
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of an unfamiliar child. In fact, mothers' autonomic responses to videotapes of the smiles and cries of their own versus an unfamiliar infant have recently been reported to differ markedly (Wiesenfeld & Klorman, 1978). The present investigation was designed to examine the specificity of parental response to familiar and unfamiliar infants by recording parents' autonomic and subjective responses to their own and an unfamiliar infant's distress vocalizations. The methodology of this study differs from those of Frodi et al. (1978a, b) in several ways: Responses to both unfamiliar and familiar children's signals were assessed, and the signals took the form of 15-sec audiotapes as opposed to 2-rain videotapes. In addition, a comparison was made between the parents' autonomic responses to the onset of the auditory stimuli against a pink noise background, whereas earlier studies assessed responses to the change in the infant's state from quiescent to distressed. It was hypothesized that parental responses to the parent's own infant would differ from responses to the unfamiliar infant and, moreover, that mothers and fathers would show differing patterns of response to the cries of their own infant.
METHOD Subjects The subjects were 16 mothers ( X age = 29.7 years, S.D. = 4.2) and 16 fathers (X age = 31.5 years, S.D. = 4.7) recruited through local pediatricians and published notes. All subjects and their infants (X = 153.6 days, S.D. = 23.2) were in good health and denied the use of medication. Psychological testing of mothers was not carried out within 3 days preceding or following the menses. All subjects had volunteered to participate in a study of infant-parent communication and agreed to listen to tape recordings of the vocalizations of their own and other same-aged infants as physiological measures were monitored. Prior to participation in the experiment, mothers were informed that during the first experimental session tape recordings of their infant's sounds, including crying, would be obtained. Upon arrival at the laboratory, mothers signed a consent form specifying the details of psychophysiological recording and initialed an information sheet which described the specific procedures employed in "eliciting the infant vocalizations. The mothers were informed during this first session that, upon returning for participation in the psychophysiological recording session, they would hear segments of tapes of their own child and those of another infant.
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Stimuli There were four variants of 15-see audiotapes of infant cries. Two of these were recordings of the subject's own infant, and the other two of a 5-month-old female unfamiliar to the subject. These four segments included one episode of each infant's anger cry (produced by physical restraint or the repeated withdrawal of a pacifier) and another of each infant's pain cry (produced by a rubber hand snap to the heel). Two additional 15-see taped sequences of 400 Hz and 100Hz pure tones with uncontrolled rise times were included as affectively neutral control stimuli. Each of the six tape-recorded segments was presented at a peak level of 80dB (SPL) and played in three consecutive trials. The unfamiliar infant cries used in this study were selected by experienced listeners as representative of five-month-old infant cries. As a further check on the representativeness of the stimuli, the following data were collected: Anger cries of ten of the infants (including the tape used as the "unfamiliar infant" cry) were selected randomly from the pool of cries used in the study and arranged in two different random orders. Thirteen mothers listened to these tapes arranged in one order; thirteen heard a second random order. Subjects first listened to the 10 cries and then, after the cries were played individually, the subject rated each cry's degree of unusualness on a scale of 0-100. Results for the two stimulus orders did not differ and so were combined in the following descriptions. A mean usualness rating for each of the ten cries was calculated, and the cries rank ordered from most unusual sounding (#1) to least (#10). The unfamiliar infant cry ranked eighth of the ten cries, confirming the earlier judgment that this infant's cries were quite usual sounding with respect to mothers' judgments and, hence, a fair representation of the cries of a five-month-old infant. Characteristics of the Cry Stimuli. Spectrographic analysis of the recorded cry stimuli were performed by means of a Kay model 7029A Spectrum Analyzer, and each cry scored for mean peak fundamental frequency and for duration of the first cry expiration. Tapes of anger cries were edited such that each stimulus segment began with a burst of rhythmical crying, a pattern consistent with Wolff's (1969) description of the " m a d " cry. Spectral analyses indicated that the mean fundamental frequency (F~i) of the cries elicited by pacifier removal was 418.74Hz (S.D. = 55.4), and by restraint 455.0H (S.D. = 84. I). These latter two values did not significantly differ with respect to F~ (t(22) = .82; n.s.). The mean duration of the first expiration o f the anger cries was .94 sec (S.D. = .50); the mean duration of the first expirations evoked by pacifier removal and restraint were 0.71 sec (S.D. = .62) and 0.99 sec (S.D. = .50), respectively; (t(22) = 1.01; n.s.). Pain cry tapes were edited to include the first 15 sec following the pain
DIFFERENTIAL PARENTAL RESPONSE
285
stimulus. Spectral analyses of the pain vocalizations indicated that the mean peak F¢ ranged from 225 to 850Hz (X = 539"1Hz, S.D. = 116.7) and the mean duration of the first cry expiration was 0.59 sec (S.D. = .67). Order. The six auditory stimuli were presented in four different orders to control for possible sequence effects. The first and fourth segments of each stimulus series were always tones, and the remaining four segments the subject's own and the unfamiliar infant's cries. The two episodes of the subject's own infant were played in succession, with order of anger and pain episodes reversed over halves of the sample. Similar counterbalancing was employed for episodes involving the unfamiliar infant.
Procedure
First Session. Upon arrival at the laboratory, the mother and infant were separated and the mother escorted to another room, where she completed a questionnaire concerning infant characteristics. The infant was seated in a high chair in preparation for tape recording. When the infant was alert and calm, the anger cry was elicited by allowing the infant to suck for 10 sec on a sucrose-coated pacifier which was then quickly taken from the infant's mouth. This procedure was repeated up to a maximum of six times, unless the infant began to cry before then. If this procedure failed to produce a cry, the child's arm and leg movements were restrained by a female experimenter who avoided eye contact with the child. After this anger cry was recorded, the infant was picked up and soothed by the female experimenter and then returned to the high chair. The pain cry was then elicited by gently snapping the heel of the infant's foot with a 6-mm-wide rubber band stretched to 7 cm. Infant vocalizations were recorded on magnetic tape by a Revox model A-77 recorder and a Superscope model EC-35 condenser microphone placed 0.5 m from the infant's mouth. Upon completion of this procedure, the infant was soothed and returned to his/her mother. Second Session. Mothers and fathers were tested individually. Upon arrival at the laboratory, each parent was given a brief explanation of psychophysiological recording and asked a series of questions concerning her/his health and recent medical history. A female experimenter then attached standard Beckman Biopotential electrodes to the medial phalanges of the index and middle fingers of the parent's nonpreferred hand. These electrodes, which served to record skin conductance, were filled with Unibase saline solution (Lykken & Venables, 1971) and secured with electrode collars and surgical tape. In addition, the experimenter attached two Beckman
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M i n i a t u r e Biopotential electrodes below the rib cage, for detecting the electrocardiogram. A Grass E34DS silver earclip was attached to the left ear to serve as a ground, hnd a mercury-filled strain gauge taped to the parent's upper chest to record respiratory cycles. The parent was then seated in a recliner chair and the r o o m lights dimmed. After a 10-min habituation period, a set of standard instructions was read over an intercom advising the parent that she/he was about to hear several brief tape-recorded segments of tones and the vocalizations o f her/his own infant and of another infant. The stimuli were played through a KLH model 31 loudspeaker positioned 2.6 m in front o f the parent's chair. Following the procedures, the six varieties o f tape-recorded segments were played in the same order played earlier, and the parent was asked to rate, on a 10-point scale, each segment for its pleasantness (1 = very pleasant; 10 = very unpleasant), his/her tension experienced during the segment (1 = extremely relaxed; 10 = tense as I've ever been), and its novelty (1 = extremely ordinary; 10 = extremely unusual). For the four segments involving cries, the subject was asked to identify the infant (own versus mother's infant) and the kind o f cry (pain, anger or other).
Measurement and Scoring of Physiological Activity. Physiological measures were recorded by a Grass model 5C polygraph. Skin conductance was recorded by means o f constant voltage circuit with a maximum sensitivity of .01/~mho/mm and skin conductance level scored with regard to the level at the onset o f each stimulus, and skin conductance response defined as the maximum amplitude change from the initial level during the 15-sec exposure to a recorded segment. The electrocardiogram was transduced by an electronic cardiotachometer into heart rate in beats/min. These data were scored by hand for each trial, for 1 sec prior to stimulus onset (baseline) and for 15 sec following stimulus onset, with a correction for cardiotachometer lag. The first cardiac cycle completed after the onset o f the stimulus was assigned as a pre- or post-stimulus beat, depending upon whether more than one half o f the cycle occurred before or after stimulus onset. The cardiotachometer (beat by beat) data were converted into average heart rate, weighted by the portion o f the second in which it occurred, in a manner consistent with Graham's (1978) recommendations for measuring heart rate through real time periods. RESULTS All physiological data were subjected to analyses o f variance, with Stimulus Order (4) and Parental Group (2) as between-subjects factors and Stimulus Types (6), Trials (3), and Seconds (7) as within-subjects factors. For the
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heart rate data, linear, quadratic and cubic trends of Trials and Seconds were evaluated. Because the analyses failed to .disclose any Stimulus Order effects, this factor was not considered in any subsequent analyses. Cardiac Rate
An analysis of variance of heart rates during the prestimulus sec indicated that comparable baseline levels preceded the six episodes: F(5, 150) ( I, n.s. An overall analysis of variance of the heart rates during the prestimulus sec and first six sec after stimulus onset yielded a significant interaction of stimulus Types and Seconds: F(30, 900) = 2.28, p ( .001. Therefore, tests for simple effects of the interaction were performed by separate analyses of variance and trend analyses, to assess the waveform of cardiac response to each of the six stimulus categories. These analyses were performed on the heart rates during the prestimulus sec and the first six sec after stimulus onset. Because heart rate reactions to their own child's pain cry and 400Hz tone changed over trials, comparisons between the conditions and groups were based on the initial trial only. Cardiac responses to the first trial of their own infant's cries and the unfamiliar child's cries are plotted in Figure I. The data are expressed as mean differences from the prestimulus values. The responses to the two cry segments (pain and anger) from the subject's own infant were characterized by comparable waveforms within each parental group (Types x Seconds, F(1, 12) = 2.19, n.s.).'Hence, the reactions to these two segments were averaged in subsequent comparisons. Similarly, the two unfamiliar infant cries evoked reactions which did not differ from each other (Types x Seconds, F(1, 12) = 4.12, n.s.) and were also combined for comparison. Finally, the two neutral-tone episodes failed to elicit significantly different reactions for either parental group and were combined for the following comparisons. The cries of the mothers' own infant elicited an initial deceleration lasting about 2 sec, followed by an acceleratory change which peaked between the fourth and fifth sec after stimulus onset. The acceleratory trend is reflected in linear, F(1, 12) = 12.93, p ( .004, and cubic, F(1, 12) = 18.93, p ( .001, components of seconds. In contrast, the fathers' cardiac response to their own child's cries was characterized by slight initial tachycardia, a secondary deceleration, and subsequent return to baseline. The cubic component of seconds approached significance, F(1, 12) = 4.67, p ( .052. When mothers' and fathers' cardiac responses to their own child's cries were compared, a marked difference in the cubic trend of second emerged, accounted for by the sharply accelerating limb of the mother's response (Seconds cubic x Group, F(1, 30) = 7.88, p (.009), which was not evident in the fathers' response. In response to the sound of the unfamiliar child's
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WIESENFELD, MALATESTA AND DELOACH
UNFA MILIA R CHILD'S CRIES
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Figure 1. Mothers' and fathers' cardiac responses to the initial trials of their own child's and an unfamiliar child's cries,
two cries, mothers' heart rates showed a deceleratory trend over the first six • seconds after stimulus onset. The cubic trend of Seconds was significant, F(I, 12) = 9.94, p < .008. The fathers' reaction to the unfamiliar cries was also in the direction of deceleration, but only approached statistical significance, Seconds quadratic, F(1, 12) = 4.12, p ( . 0 6 5 . A comparison of mothers' and fathers' responses to the unfamiliar cries indicated comparable pattems of cardiac change. (All trends of Seconds x Group, F(1, 30) ( I, n.s.). Analysis of cardiac responses to the neutral tones disclosed a nonsignificant biphasic change for mothers (Seconds cubic, F(1, 12) = 4.41, p (.06) and a significant deceleratory response in the fathers Seconds quadratic, F(1, 12) = 10.09, p (.008; Seconds cubic, F1, 12) = 5.81, p < .04). A comparison of mothers' and fathers' responses to the tones indicated that the fathers' bradycardia was more pronounced (Seconds quadratic x Group, F(I, 30) = 8.40, p (.007). Skin C o n d u c t a n c e
Analysis of variance conducted on the baseline skin conductance levels preceding each trial of each stimulus type failed to disclose differences between the arousal levels of the two parental groups, F(1, 30) = 2.77, n.s. Analysis of variance of the skin conductance response values revealed a significant difference in magnitude of response among the six stimulus types, F(5, 150) = 2.63, p ( .026. However, nq difference in response magnitude was found
DIFFERENTIAL PARENTAL RESPONSE
SKIN CONDUCTANCE
289
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Figure 2. Mothers' and fathers' electrodermal responses to the pain and anger cries of their own child and to the cries of the unfamiliar infant.
between the mothers and fathers (Types x Group F(5, 150) < 1, n.s.). Comparisons between the stimulus types were performed on the means of the three trials of each type for the combined mothers' and fathers' data by means of Neumann-Keuls tests with a probability level set at .05. These data are displayed in Figure 2. A pairwise test of the means indicated tl~at the parents' skin conductance response to their own baby's pain cry exceeded l:eactions to all other types 6o .01). Skin conductance responses to the other five stimulus types did not differ.
Subjective Responses Table 1 depicts the parents' subjective ratings of the six stimulus types.
WlESENFELD, MALATESTA AND DELOAGH
290
TABLE 1 Mothers' and Fathers' Subjective Ratings of the Stimuli
Stimulus Type:
Own Anger Pain
Unfamiliar Anger Pain
Tone 400Hz lO00Hz
Mothers PleasantnessUnpleasantness Tension Novelty
7.25 7.25 3.69
8.56 8.38 4.81
6.50 5.81 4.88
6.88 6.25 4.38
5.25 4.06 5.06
5.18 4.75 4.69
Fathers PleasantnessUnpleasantness Tension Novelty
6.06 5.06 3.75
7.19 6.31 4.50
6.13 4.88 4.63
6.50 5.69 4.56
5.88 4.69 5.31
5.38 3.69 5.44
Analysis of variance of the ratings of pleasantness-unpleasantness revealed significant differences among the types (F(5, 150) = 16.73, p ~ .001), but there were no mother versus father group differences in pattern or magnitude of these ratings (F(1, 30) = 1.19, n.s.). As examination of Table 1 illustrates, mothers rated the sound of their own child's pain cry to be more unpleasant than any of the other types. Pairwise tests indicated that the mothers' rating of the unpleasantness of this cry was.significantly greater than their ratings of the unfamiliar child's anger cry and that it exceeded fathers' ratings of unpleasantness for both unfamiliar cries (p (.05), but not the fathers' rating of the familiar child's pain cry. The mothers rated their own child's anger cry as next most unpleasant; however, this rating did not differ statistically from their ratings, nor from fathers' unpleasantness ratings, of the two unfamiliar cries. Analysis of variance of the ratings of subjective tension experienced during the stimulus episodes revealed a mother versus father group difference (F(1, 30) = 4.52, p (.042) and differences among the Stimulus Types (F(5, 150) = 20.61, p (.001). According to the Neumann-Keuls test, mothers' ratings of their level of tension during the episode of their own child's pain cry was greatest, higher than all of'the other mother and father ratings of tension except for mothers' rating of tension during their own child's anger cry (p (.05). Mothers also rated their own child's anger cry as more tension-producing than the 1000Hz tone. Analysis o.f variance of the novelty ratings yielded an effect for Stimulus Types (F(5, 150) = 3.0, p ( . 0 2 ) . The tones were rated as most unusual, with ratings for the 400Hz tone exceeding the two own child's cries and the unfamiliar infant's pain cry. The unfamiliar infant's anger cry was judged
DIFFERENTIAL PARENTAL RESPONSE
291
to be more unusual than the own child's anger cry, and the own child's pain cry more unusual than the own child's anger, cry (p ( . 0 5 ) . Finally, the sound of the unfamiliar infant's pain cry was judged to be more unusual than the own child's anger cry.
Recognition Accuracy One- and two-sample proportion tests were employed to analyze the identification data (Freund, 1973; Anderson & Sclove, 1978). Mothers were able to correctly identify the sounds of their own infants 97070 of the time, fathers 84070 of the time. Mothers were able to correctly identify the sounds of another infant as unfamiliar (i.e., not their own child) 75070 of the time, fathers 44°70 of the time. The combined overall recognition accuracy was thus 86°70 for mothers and 64°70 for fathers; both groups' rates exceeded the chance level of 50070 (p < .001, a n d p < .01, respectively). Incorrect identifications were divided between relatively few of their own infants' cries misidentified as belonging to another infant (3070 for mothers, 1607o for fathers), and relatively greater numbers of unfamiliar cries, misidentified as belonging to the subject's own infant (25°7o for mothers, 56070 for fathers). TABLE 2 Number and Percent (in Parentheses) Correct Identification of Type of Cry of Own and Unfamiliar Infant By Mothers and Fathers (n = 16 for each cell)
Pain Infant Own Unfamiliar
Anger
Mothers
Fathers
Mothers
Fathers
8 (50) 4 (25)
6 (38) 5 (31)
13 (81) 10 (63)
8 (50) 8 (50)
Table 2 displays the parents' judgments of the type of cry heard in terms of percentages of correct judgments plotted by the actual identity of the stimulus infant and type of cry played (pain yersus anger). The overall accuracy of mothers was 55070, a rate Significantly better than a chance level of .33 (z = 3.78, p ( . 0 1 ) given the three choices of anger, pain or other; the corresponding rate for fathers was 42070, which did not exceed the chance level (z = 1'.56,p (.06). The percentage of mothers' correct judgments when listening to their own child's sounds (pain and anger combined) was 65.5070, significantly better than chance (p ( . 0 1 ) . The corresponding rate for fathers (42070) was not greater than chance (p (.01). The percentages of cot-
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WIESENFELD, MALATESTA AND DELOACH
rect cry-type judgments for unfamiliar infant cries (pain and anger combined) were 44°7o and 41 070, for mothers and fathers respectively; in neither case was this percentage different from the chance level. A comparison of mothers' accuracy scores t'or their own infant (65.507o) and for unfamiliar infant cries (44070) revealed that mothers were significantly more accurate in differentiating among the cries of their own child (p ( . 0 5 ) . For fathers, however, a similar comparison of accuracy scores for own versus unfamiliar cries was not significant, indicating that the fathers were not able to better discriminate among the various sounds of their own child. DISCUSSION The results indicate that mothers and fathers differ in their autonomic responsiveness to their own infant's distress signals. Mothers exhibited cardiac response patterns consistent with a defensive reaction (i.e., tachycardia) when listening to their own child's cries, whereas fathers responded with a marginally significant cardiac deceleration, a pattern consistent with the orienting response. Differential experience with and exposure t o the infant may underlie these differences in responsiveness, as well as different role behaviors which largely assign the tasks of physical caregiving to mothers. Because it is typically the mother, rather than the father, who takes responsibility for soothing her distressed infant, the maternal pattern of response observed in the present investigation may reflect a pattern described by Obrist (1976) as active coping, whereas the paternal pattern may be more consistent with a passive coping process in the face of the infant's distress signals. This possibility was supported by the anecdotal accounts of our research subjects; many of the mothers reported that they seemed less able to ignore their child's cries than their spouses. In terms of responsiveness to an unfamiliar infant's distress signals, mothers and fathers autonomic response patterns were comparable. This finding is consistent with the earlier reports of Frodi et al. (1978a, 1978b). However, the response pattern associated with the unfamiliar child's cries was of cardiac deceleration, or an orienting response. The orienting pattern may relate to the slightly greater novelty of the cries in comparison to one's own child's sounds, or, alternatively, to a more passive attitude on the part of mothers listening to another child in distress. The subjective response data indicate that mothers find the cries of unfamiliar children moderately aversive, yet the defensive response pattern did not emerge. Perhaps cultural values constraining unrelated adults from "interfering" with another person's child may belie the observed own-versus-unfamiliar child response patterns in mothers. No differences in cardiac responsiveness to the pain-versus-anger vocalizations were observed in either parental group. Interestingly, the pain
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vocalizations of the parent's own child evoked the largest electrDdermal responses for both parent groups. Perhaps this latter measure is more sensitive to the heightened aversiveness of this kind of distress signal. The subjective ratings support the notion that pain crying is especially unpleasant to parents, especially mothers. The results indicate that mothers' reactions to their own and unfamiliar infants are not equivalent. However, the question remains: Is one's own infant's cry especially unpleasant because it is more difficult to ignore and, therefore, more noxious and aversive, or is it more unpleasant because it tends to arouse similar emotions in the caregiver through an empathic process? Wiesenfeld and Malatesta (in press) have suggested that mothers respond to their infant's cries because the infant's distress touches an "empathic core." Some workers (Frodi eta!., 1978b; Lamb, 1978) have stressed the aversive properties of the cry, and have suggested that caregivers respond to crying in order to terminate aversive stimulation. Whatever the case, the results of the present study confirm that mothers experience their own child's distress as especially unpleasant. Mothers were more accurate in reqognizing their own child's cries and in differentiating among cry types thari fathers. Perhaps this phenomenon reflects the mother's greater experience in soothing the child. The results of the present study contrast with those of Frodi et al. (1978a, 1978b) in two ways. In the Frodi et al. studies, it was concluded that mothers and fathers physiological responsiveness to infant signals did not differ. In the present study it was found that differences did indeed exist, but only with respect to responsiveness to one's own child's signals. Frodi et al. described the general reaction of parents to crying infants to include cardiac acceleration, whereas our results suggest that parental response to unfamiliar infant crying is associated with heart rate deceleration. Perhaps this difference in the direction of change between the two laboratories results from the basic methodological differences described in the Introduction. The differential maternal response to own-versus-unfamiliar infant's signals found in thepresent study illustrates that adult responsivity to infant signals may vary with relatedness to the infant. It is highly likely that the signals ~of one's own offspring comprise a set of signals with unique meaning. As such, future experimental stuclies of parental response to infants should include the parent's own child's signals as stimuli. t
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