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The imitation of pitch in infants
The Imitation of Pitch in Infants* W I L L I A M KESSEN JANICE L E V I N E
Yale University KENNETH A. WENDRICH
Neighborhood Music School New Haven, Connecticut
Twenty-three infants, between 3 and 6 months of age, were seen three times in a study of pitch-matching. In the third session, the babies were presented with two or three sung tones (D, F, and A above middle C). All of the babies responded by vocalizing on the presented pitch significantly often. The ability of infants in the first six months of life to imitate pitched tones poses questions important bath for theories of imitation and for early music education.
Most current theories of imitation, whether in the learning theory tradition (Bandura & Waiters, 1963; Miller & Dollard, 1941) or in the psychoanalytic tradition (Freud, 1924), assume that matching behavior by children is primarily a social act and that matching behavior requires perceptual and cognitive skills not likely to be available much before the end of the first year of life. However, several dissents from the common view exist--the occasional appearance of imitation items on infant tests (among the first, Hetzer & Wolf, 1928), the almost casual assertion of early imitation by Piaget (1945), the recent reports of infantile matching behavior by Meltzoff and Moore (1977), and, most important for us, Ostwaid's (1973) reading of research on the early discrimination of pitch. We wanted to study imitation of pitch in young infants chiefly for two reasons. First, the perception and production of pitched sounds can be studied in children from birth on; we saw the child's response to pitch as an almost uniquely ~'The research reported here was supported by a grant to William Kessen and Katherine Nelson from the Carnegie Corporation of New York and by the Neighborhood Music School of New Haven. We are grateful to Philip deGreg for his help in a preliminary study and to William Cobb, Susan Lichten, Karen Nelson, and Carolyn Wendrich of the Neighborhood Music School who, with Kenneth A. Wendrich, served as our judges. Janice Levine is now at Harvard University.
93
94
KESSEN, LEVINE, AND WENDRICH
apt system for the study of the development of imitation. Second, we believed that, if young children--specifically, children who do not speak or comprehend language--are capable of pitch imitation, the capacity would have important implications both for theories of development and for the practice of early music education.
METHOD
Subjects Twelve girls and 12 boys participated in three sessions of the study. Usable data were obtained from 23 of the babies; the records for one infant were not scorable. The children were between 90 and 162 days of age when first seen in Session I (their median age was 131 days), between 106 and 199 days at Session II (median of 146 days), and between 114 and 208 days at Session III (median of 171 days). All infants were recruited by telephone calls to parents who had indicated an interest.in Yale's Studies of Infancy.
Procedure All observations were made in a pleasantly furnished, soundproof laboratory of the Department of Psychology at Yale University. The sessions were informal and designed to be comfortable for baby and parent; the experimenter (Janice Levine) and the parent commented naturally on the baby's activities; the parent would occasionally assist by singing a note to the child; and presentation of stimuli was not timed strictly by the clock. The baby sat in a baby seat between his mother and the experimenter within pickup range of two SONY 25S microphones wired to two channels of a four-channel TEAC A-3340S audiorecorder. Each session with each infant varied somewhat from all others but every session had the following basic sequence: (I) Greetings and a short interview with the parent. In the first session, questions were asked about the musical interests of the family and about the occurrence of music in the home; a rough schedule for later visits was established. In Sessions II and III, the informal interview dealt with the work of parent and child with pitched sounds since the preceding visit. (2) A presentation, by pitchpipe and by experimenter's voice, t of one to three of a set of standard test notes--D, F, and A above middle C. All stimulus presentations and all of the baby's vocalizations were taped. (3) A discussion with the parent about procedure for daily sessions at home with the baby prior to the next visit to the laboratory, approximately two weeks later. The sessions each served as a procedural demonstration for the mothers to follow. ~The pitchpipe and human voice were used interchangeably and according to the baby's observed preference.
THE IMITATION OF PITCH IN INFANTS
95
The tones D, F, and A were chosen for several re~lsons. First, we observed from preliminary observation that the tones fell within the baby's normally occurring range of produced sounds, a belief recently confirmed by Laufer and Horii (1978). Further, we were interested in the implications of our observations for music education as well as for infant development. Finally, pitchpipes necessary for mothers who could not sing on pitch typically are built with Western musical intervals. Each session had its own particular focus and was designed primarily to increase sequentially the difficulty of the baby's task. In Session ! the mother was asked to try to make her baby vocalize by whatever means she could, for the purpose of recording the baby's normal pitch range. Each naturally occurring vocalization was imitated by the experimenter as exactly as possible. Mothers were instructed to follow this pattern of imitation for at least 5 minutes daily, attempting to match the baby's pitch, inflection, and vowel sound as exactly as possible. Session II began along the same line to establish an active vocal interchange between the infant and the experimenter. After approximately 5 minutes, the test note F above middle C was introduced. Every vocalization by the infant was answered with the F pitch, sung on an " a h . " Mothers were each given a pitchpipe, instructed to follow the demonstrated procedure, and asked to use the pitchpipe as a frequent check for pitch accuracy. Mothers who could not match pitches were instructed to use the pitchpipe instead of their voices to establish the correct pitch center for the baby to hear, but nonethel.ess to follow each tone with a vocal " a h " sound. Session III followed this format again to record progress. When the infant successfully matched the F pitch five or more times, a second pitch was then introduced. In order to stay within the babies' normal range, this note was either the D below or the A above F. After the second pitch was successfully matched by the infant, the experimenter again sounded the original F. Most babies sang the F back. If the child accomplished these transitions with little difficulty, the third pitch was then introduced and the procedure repeated. Each session lasted approximately 30 minutes.
Data Analysis The audiotapes were, almost without exception, of high quality; the child's voice and the voices of adults could be readily distinguished by timbre. In effect, the tapes represented "conversations" between the experimenter and a baby; the baby's utterances were frequent but short and the presence of the experimenter's stimulhs tone and the baby's response nearby made it possible to score the records as sounds of the baby that were pitch-matches or that represented standard musical intervals. We relied on trained musicians to judge the babies' hits and misses of the presented pitches. Segments of tape, approximately 15 minutes in length, were selected from Session III (in four cases, it was necessary to select segments from earlier sessions in order to get a long enough continuous sequence
96
KESSEN, LEVINE, AND WENDRtCH
of stimulation and response). Session II! was chosen for uniformity to diminish the influence of baby's and parent's adaptation to the laboratory and to take advantage of whatever "training" effects occurred. Because much of the change we saw in babies'behaviors between Session I and Session III can be assigned to general adaptation to the experimental and social.setting, a rigorous assessment of the effects of training could not be made. The most important reason for choosing Session III for closer study, however, was because the procedure used could not have produced a misleading mutual imitation in which, basically, the adult imitates the child. The selected segments were played to five members of the staff and faculty of the Neighborhood Music School in a room at the school. The judges evaluated all discernible pairs of events defined by the experimenter's stimulation (ES) followed by infant's response (IR). In the presence of such a pair, each judge evaluated the pitch of ES and the pitch of IR; the evaluation was checked into a 3-by-3 matrix with D, F, and A of ES on one margin and D, F, and A of IR on the other. The judges accepted as matches those responses of a baby that were within a quarter-tone of the sung note. Occasional unpitched responses (squeals, for example) were not evaluated. In summary, then, 15-minute segments of tape were played to five judges. Each segment consisted of several presentations of pitched sounds by an adult 2 and the consequent vocal behavior of a child. The judgements were cast into a stimulus--response matrix which permitted the evaluation of the child's accuracy of imitation.
RESULTS General
Observations
The fact does not submit to numerical analysis, but the babies worked hard at their assignment. They watched the experimenter closely and they vocalized to her often and energetically- in short, they accepted ths task with a willingness that even our pilot observations had not prepared us for. Pitch imitation in young infants may be an outlandish idea to develop.mental psychologists; it, or the attempt at it, seems natural to young infants who are happily engaged in the task.
Reliability Two measures of the reliability of judges were computed. The first assesses the ability of the five judges to segment the tapes they heard into ES-IR pairs. -'The babies demonstrated no apparent recognition or preference for the experimenter's or parent's (father or mother) voice,
THE IMITATION OF PITCH IN INFANTS
97
Kendall's W for the rank correlation of all judges over all children for number of ES-IR pairs scored was .91 ( X 2 = 100.10, df = 22,'p < .001). The second index of reliability was based on the agreement of judges about the babies' hits and misses of presented pitch. Because the range of variation in hit proportion was narrow, the measure underestimates the true correlation; nonetheless, Kendall's W for all judges over all children on proportion of hits was .58 (X 2 = 64.13, df = 22, p < .001). On the basis of these results, the judgments of the five judges were collapsed to a single 3-by-3 matrix for each child with the means rounded to the nearest whole number.
Pitch-matching The mean-judge matrix for each child was examined. The range in number of ES-IR pairs per child was from 10 to 50 for each 15-minute segment (with a mean of 24.9). The proportion of hits--the diagonal of the (D,F,A)Es-by(D,F,A)m matrix--ranged from .55 to .90 (with a mean of .68). The observed proportion of hits departed significantly from a chance 33.3% 3-by-3 matrix (z = 17.95, p < .001) and from a far more conservative 50% hit rate (z = 9.34, p < .001). We were struck, too, by the fact that every baby performed above the conservative hit rate. The proportion of pitched sounds that were not judged to be within a quarter-tone of D, F, and A was small; no baby sang as much as 15% off a member of the triad. Further, every judge, considered separately, heard the babies pitch-matching well beyond the usual standards for significance (the lowest z of the ten computed was 4.40, p < .01) Many of the individual matrixes had empty cells; to permit uniform evaluation, all matrixes were reduced to a 2-by-2 form (eight were (D,F)Es-by-(D,F)m and 15 were (F,A)Es-by-(F,A)m), a procedure which maintained just under 90% of the ES-IR pairs. All babies had more correct pitch-matchings than incorrect responses in the reduced matrix. However, a raw hit measure does not take into account either variability of stimulus presentation or response bias. Therefore, each set of data was examined under the following question: With the number of presentations of each pitch taken into account, did the baby match the pitch more often than not? Thus, in a (D,F)Es-by-(D,F)IR matrix, a baby could display a ( + , + ) pattern-that is, he could vocalize more Ds than Fs when D was presented and more Fs than Ds when F was presented--or he could display one of five other weaker patterns of imitation) Eighteen of the 23 babies showed the ( + , + ) pattern, three the (0,+) 3Taking 0 to represent a tie, the five remaining patterns are (0+ or +0), ( - + or +-), (0,0), (0.- or -,0), and ( - , - ) the last indicating "'anti-matching.""
98
KESSEN, LEVINE, AND WENDRICH
pattern, and two the ( - , +) pattern; we can, therefore reject with confidence explanations of the babies' imitation as dependent on chance or response bias. Neither number of ES-IR pairs nor proportion of pitch-matches varied with sex of the babies. In consideration of the narrow age range of the babies in Session III, it was not surprising no variation in pitch-matching with age was found. Whatever abilities are necessary to match pit~:hed tones, they are apparently available to children as young as 18 weeks. Moreover, there were several clear examples of exact pitch-matching in Session I as well as both occasional matching of two-tone sequences (descending minor thirds) and rarer but dramatic examples of octave response in the later sessions. We could detect no relation between musical competence or interest of the parents and the infant's ability to match pitches, although the range of variation was from children with no music in the home to children of professional musicians. Statistics aside, Table 1 may help to carry the message of the results; it shows the aggregation across all infants of the (D,F,A)Es-by-(D,F,A)m matrixes. F was the most common stimulus in these segments and F was the most common response, but responses of F to the presentation of F (60.5%) were not more likely than D responses to D (63.4%) or A responses to A (73%). Note may also be taken of the fact that failures of imitation were almost always at the nearer interval; the more extreme D-for-A and A-for-D errors occurred only ten times throughout the observations. Not represented in Table 1 is the fact that a large proportion of misses occurred as a result of delay in transition; that is, the baby would linger on a previously matched pitch immediately following a change in stimulus pitch. Such occasional persistence argues a~ainst the possibility of mutual imitation. TABLE 1 ES--IR Aggregate Response Matrix Infant
Experimenter's Stimulus D F A
O 49 20 2
Response [24 210 39
A 8 101 116
DISCUSSION. Infants match pitched tones. Before the middle of the first year of life, babies can not only perceive variations in the tonal surround; they can imitate pitches. The present report presents more a demonstration of that fact than an experimental analysis of it; many questions remain about the antecedents of pitch-matching and about its fate as children begin to speak. For example, does the onset of speech diminish the baby's ability to match pitches either because of the relative low importance (at/east in English) of precise tonal representation or because
THE IMITATION OF PITCH IN INFANTS
99
attention to pitch interferes with skills necessary to speech? Are there marks in language of the baby's early sensitivities? It is interesting that Bernstein (1976) has cited our descending minor third as a universal characteristic of human languages. How is early pitch-matching related to later musical skills? We can return now, demonstration in hand, to our initiating questions. What revisions do our findings require in current theories of imitation? What implications do they have for early music education? Our findings pose significant problems for theories dependent on simple reinforcement contingencies or on a critical developmental transition in the second half of the first year. We cannot systematically rule out an interpretation of our findings based on the experience of babies in Sessions I and II or at home. However, the independence of the phenomenon from the occurrence of music at home, as well as the sometimes startling pitch-matching of babies in Session I, force us to look for more complicated epigenetic explanations. Perhaps the most plausible proposal is that, somewhat analogously to birdsong (Marler & Hamilton, 1966), the baby brings a congenital readiness to respond to pitched tones which is then adaptively modified to his experience of sounds in the first years of life. On the side of education, the research gave even more provocative answers. It may be possible that pitch-matching is usual in babies and that, for most of them, the ability is lost with the onset of language or with the failure of many environments to support its continuation. Early music education may require, not so much the building of new perceptual and cognitive structures, but rather the maintenance of capacities which, for whatever evolutionary reason, are available to most children.
REFERENCES Bandura, A., & Waiters, R. H. Social learning and personalit3, development. New York: Holt, Rinehart, & Winston, 1963. Bernstein, L. The unanswered question: Six talks at Harvard. Cambridge: Harvard University Press, 1976. Freud, S. The passing of the Oedipus-complex. In Collected papers, Vol. II. London: Hogarth, 1924. Hetzer, H., & Wolf, K. Babytests. Zeitschrift fiir Psychologie, 1928, 107, 62-104. Laufer, Z. L., & Horii, Y. Fundamental frequency characteristics of infant non-distress vocalization during first twenty-four weeks. Journal of Child Language, 1978, 4, 171-184. Marler, P., & Hamilton, W. Mechanisms of animal behavior. New York: Wiley & Sons, 1966. Meltzoff, A. N., & Moore, M. K. Imitation of facial and manual gestures by human neonates. Science, 1977, 198, 75-78, Miller, N. E., & Dollard, J. Social learning and imitation. New Haven: Yale University Press, 194 I. Ostwald, P. F. Musical behavior in early childhood. Developmental Medicine & Child Neurology, 1973, 15, 371. Piaget, J. Play, dreams, and imitation. (French edition, 1945.) New York: Norton, 1951.
Yale University KENNETH A. WENDRICH
Neighborhood Music School New Haven, Connecticut
Twenty-three infants, between 3 and 6 months of age, were seen three times in a study of pitch-matching. In the third session, the babies were presented with two or three sung tones (D, F, and A above middle C). All of the babies responded by vocalizing on the presented pitch significantly often. The ability of infants in the first six months of life to imitate pitched tones poses questions important bath for theories of imitation and for early music education.
Most current theories of imitation, whether in the learning theory tradition (Bandura & Waiters, 1963; Miller & Dollard, 1941) or in the psychoanalytic tradition (Freud, 1924), assume that matching behavior by children is primarily a social act and that matching behavior requires perceptual and cognitive skills not likely to be available much before the end of the first year of life. However, several dissents from the common view exist--the occasional appearance of imitation items on infant tests (among the first, Hetzer & Wolf, 1928), the almost casual assertion of early imitation by Piaget (1945), the recent reports of infantile matching behavior by Meltzoff and Moore (1977), and, most important for us, Ostwaid's (1973) reading of research on the early discrimination of pitch. We wanted to study imitation of pitch in young infants chiefly for two reasons. First, the perception and production of pitched sounds can be studied in children from birth on; we saw the child's response to pitch as an almost uniquely ~'The research reported here was supported by a grant to William Kessen and Katherine Nelson from the Carnegie Corporation of New York and by the Neighborhood Music School of New Haven. We are grateful to Philip deGreg for his help in a preliminary study and to William Cobb, Susan Lichten, Karen Nelson, and Carolyn Wendrich of the Neighborhood Music School who, with Kenneth A. Wendrich, served as our judges. Janice Levine is now at Harvard University.
93
94
KESSEN, LEVINE, AND WENDRICH
apt system for the study of the development of imitation. Second, we believed that, if young children--specifically, children who do not speak or comprehend language--are capable of pitch imitation, the capacity would have important implications both for theories of development and for the practice of early music education.
METHOD
Subjects Twelve girls and 12 boys participated in three sessions of the study. Usable data were obtained from 23 of the babies; the records for one infant were not scorable. The children were between 90 and 162 days of age when first seen in Session I (their median age was 131 days), between 106 and 199 days at Session II (median of 146 days), and between 114 and 208 days at Session III (median of 171 days). All infants were recruited by telephone calls to parents who had indicated an interest.in Yale's Studies of Infancy.
Procedure All observations were made in a pleasantly furnished, soundproof laboratory of the Department of Psychology at Yale University. The sessions were informal and designed to be comfortable for baby and parent; the experimenter (Janice Levine) and the parent commented naturally on the baby's activities; the parent would occasionally assist by singing a note to the child; and presentation of stimuli was not timed strictly by the clock. The baby sat in a baby seat between his mother and the experimenter within pickup range of two SONY 25S microphones wired to two channels of a four-channel TEAC A-3340S audiorecorder. Each session with each infant varied somewhat from all others but every session had the following basic sequence: (I) Greetings and a short interview with the parent. In the first session, questions were asked about the musical interests of the family and about the occurrence of music in the home; a rough schedule for later visits was established. In Sessions II and III, the informal interview dealt with the work of parent and child with pitched sounds since the preceding visit. (2) A presentation, by pitchpipe and by experimenter's voice, t of one to three of a set of standard test notes--D, F, and A above middle C. All stimulus presentations and all of the baby's vocalizations were taped. (3) A discussion with the parent about procedure for daily sessions at home with the baby prior to the next visit to the laboratory, approximately two weeks later. The sessions each served as a procedural demonstration for the mothers to follow. ~The pitchpipe and human voice were used interchangeably and according to the baby's observed preference.
THE IMITATION OF PITCH IN INFANTS
95
The tones D, F, and A were chosen for several re~lsons. First, we observed from preliminary observation that the tones fell within the baby's normally occurring range of produced sounds, a belief recently confirmed by Laufer and Horii (1978). Further, we were interested in the implications of our observations for music education as well as for infant development. Finally, pitchpipes necessary for mothers who could not sing on pitch typically are built with Western musical intervals. Each session had its own particular focus and was designed primarily to increase sequentially the difficulty of the baby's task. In Session ! the mother was asked to try to make her baby vocalize by whatever means she could, for the purpose of recording the baby's normal pitch range. Each naturally occurring vocalization was imitated by the experimenter as exactly as possible. Mothers were instructed to follow this pattern of imitation for at least 5 minutes daily, attempting to match the baby's pitch, inflection, and vowel sound as exactly as possible. Session II began along the same line to establish an active vocal interchange between the infant and the experimenter. After approximately 5 minutes, the test note F above middle C was introduced. Every vocalization by the infant was answered with the F pitch, sung on an " a h . " Mothers were each given a pitchpipe, instructed to follow the demonstrated procedure, and asked to use the pitchpipe as a frequent check for pitch accuracy. Mothers who could not match pitches were instructed to use the pitchpipe instead of their voices to establish the correct pitch center for the baby to hear, but nonethel.ess to follow each tone with a vocal " a h " sound. Session III followed this format again to record progress. When the infant successfully matched the F pitch five or more times, a second pitch was then introduced. In order to stay within the babies' normal range, this note was either the D below or the A above F. After the second pitch was successfully matched by the infant, the experimenter again sounded the original F. Most babies sang the F back. If the child accomplished these transitions with little difficulty, the third pitch was then introduced and the procedure repeated. Each session lasted approximately 30 minutes.
Data Analysis The audiotapes were, almost without exception, of high quality; the child's voice and the voices of adults could be readily distinguished by timbre. In effect, the tapes represented "conversations" between the experimenter and a baby; the baby's utterances were frequent but short and the presence of the experimenter's stimulhs tone and the baby's response nearby made it possible to score the records as sounds of the baby that were pitch-matches or that represented standard musical intervals. We relied on trained musicians to judge the babies' hits and misses of the presented pitches. Segments of tape, approximately 15 minutes in length, were selected from Session III (in four cases, it was necessary to select segments from earlier sessions in order to get a long enough continuous sequence
96
KESSEN, LEVINE, AND WENDRtCH
of stimulation and response). Session II! was chosen for uniformity to diminish the influence of baby's and parent's adaptation to the laboratory and to take advantage of whatever "training" effects occurred. Because much of the change we saw in babies'behaviors between Session I and Session III can be assigned to general adaptation to the experimental and social.setting, a rigorous assessment of the effects of training could not be made. The most important reason for choosing Session III for closer study, however, was because the procedure used could not have produced a misleading mutual imitation in which, basically, the adult imitates the child. The selected segments were played to five members of the staff and faculty of the Neighborhood Music School in a room at the school. The judges evaluated all discernible pairs of events defined by the experimenter's stimulation (ES) followed by infant's response (IR). In the presence of such a pair, each judge evaluated the pitch of ES and the pitch of IR; the evaluation was checked into a 3-by-3 matrix with D, F, and A of ES on one margin and D, F, and A of IR on the other. The judges accepted as matches those responses of a baby that were within a quarter-tone of the sung note. Occasional unpitched responses (squeals, for example) were not evaluated. In summary, then, 15-minute segments of tape were played to five judges. Each segment consisted of several presentations of pitched sounds by an adult 2 and the consequent vocal behavior of a child. The judgements were cast into a stimulus--response matrix which permitted the evaluation of the child's accuracy of imitation.
RESULTS General
Observations
The fact does not submit to numerical analysis, but the babies worked hard at their assignment. They watched the experimenter closely and they vocalized to her often and energetically- in short, they accepted ths task with a willingness that even our pilot observations had not prepared us for. Pitch imitation in young infants may be an outlandish idea to develop.mental psychologists; it, or the attempt at it, seems natural to young infants who are happily engaged in the task.
Reliability Two measures of the reliability of judges were computed. The first assesses the ability of the five judges to segment the tapes they heard into ES-IR pairs. -'The babies demonstrated no apparent recognition or preference for the experimenter's or parent's (father or mother) voice,
THE IMITATION OF PITCH IN INFANTS
97
Kendall's W for the rank correlation of all judges over all children for number of ES-IR pairs scored was .91 ( X 2 = 100.10, df = 22,'p < .001). The second index of reliability was based on the agreement of judges about the babies' hits and misses of presented pitch. Because the range of variation in hit proportion was narrow, the measure underestimates the true correlation; nonetheless, Kendall's W for all judges over all children on proportion of hits was .58 (X 2 = 64.13, df = 22, p < .001). On the basis of these results, the judgments of the five judges were collapsed to a single 3-by-3 matrix for each child with the means rounded to the nearest whole number.
Pitch-matching The mean-judge matrix for each child was examined. The range in number of ES-IR pairs per child was from 10 to 50 for each 15-minute segment (with a mean of 24.9). The proportion of hits--the diagonal of the (D,F,A)Es-by(D,F,A)m matrix--ranged from .55 to .90 (with a mean of .68). The observed proportion of hits departed significantly from a chance 33.3% 3-by-3 matrix (z = 17.95, p < .001) and from a far more conservative 50% hit rate (z = 9.34, p < .001). We were struck, too, by the fact that every baby performed above the conservative hit rate. The proportion of pitched sounds that were not judged to be within a quarter-tone of D, F, and A was small; no baby sang as much as 15% off a member of the triad. Further, every judge, considered separately, heard the babies pitch-matching well beyond the usual standards for significance (the lowest z of the ten computed was 4.40, p < .01) Many of the individual matrixes had empty cells; to permit uniform evaluation, all matrixes were reduced to a 2-by-2 form (eight were (D,F)Es-by-(D,F)m and 15 were (F,A)Es-by-(F,A)m), a procedure which maintained just under 90% of the ES-IR pairs. All babies had more correct pitch-matchings than incorrect responses in the reduced matrix. However, a raw hit measure does not take into account either variability of stimulus presentation or response bias. Therefore, each set of data was examined under the following question: With the number of presentations of each pitch taken into account, did the baby match the pitch more often than not? Thus, in a (D,F)Es-by-(D,F)IR matrix, a baby could display a ( + , + ) pattern-that is, he could vocalize more Ds than Fs when D was presented and more Fs than Ds when F was presented--or he could display one of five other weaker patterns of imitation) Eighteen of the 23 babies showed the ( + , + ) pattern, three the (0,+) 3Taking 0 to represent a tie, the five remaining patterns are (0+ or +0), ( - + or +-), (0,0), (0.- or -,0), and ( - , - ) the last indicating "'anti-matching.""
98
KESSEN, LEVINE, AND WENDRICH
pattern, and two the ( - , +) pattern; we can, therefore reject with confidence explanations of the babies' imitation as dependent on chance or response bias. Neither number of ES-IR pairs nor proportion of pitch-matches varied with sex of the babies. In consideration of the narrow age range of the babies in Session III, it was not surprising no variation in pitch-matching with age was found. Whatever abilities are necessary to match pit~:hed tones, they are apparently available to children as young as 18 weeks. Moreover, there were several clear examples of exact pitch-matching in Session I as well as both occasional matching of two-tone sequences (descending minor thirds) and rarer but dramatic examples of octave response in the later sessions. We could detect no relation between musical competence or interest of the parents and the infant's ability to match pitches, although the range of variation was from children with no music in the home to children of professional musicians. Statistics aside, Table 1 may help to carry the message of the results; it shows the aggregation across all infants of the (D,F,A)Es-by-(D,F,A)m matrixes. F was the most common stimulus in these segments and F was the most common response, but responses of F to the presentation of F (60.5%) were not more likely than D responses to D (63.4%) or A responses to A (73%). Note may also be taken of the fact that failures of imitation were almost always at the nearer interval; the more extreme D-for-A and A-for-D errors occurred only ten times throughout the observations. Not represented in Table 1 is the fact that a large proportion of misses occurred as a result of delay in transition; that is, the baby would linger on a previously matched pitch immediately following a change in stimulus pitch. Such occasional persistence argues a~ainst the possibility of mutual imitation. TABLE 1 ES--IR Aggregate Response Matrix Infant
Experimenter's Stimulus D F A
O 49 20 2
Response [24 210 39
A 8 101 116
DISCUSSION. Infants match pitched tones. Before the middle of the first year of life, babies can not only perceive variations in the tonal surround; they can imitate pitches. The present report presents more a demonstration of that fact than an experimental analysis of it; many questions remain about the antecedents of pitch-matching and about its fate as children begin to speak. For example, does the onset of speech diminish the baby's ability to match pitches either because of the relative low importance (at/east in English) of precise tonal representation or because
THE IMITATION OF PITCH IN INFANTS
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attention to pitch interferes with skills necessary to speech? Are there marks in language of the baby's early sensitivities? It is interesting that Bernstein (1976) has cited our descending minor third as a universal characteristic of human languages. How is early pitch-matching related to later musical skills? We can return now, demonstration in hand, to our initiating questions. What revisions do our findings require in current theories of imitation? What implications do they have for early music education? Our findings pose significant problems for theories dependent on simple reinforcement contingencies or on a critical developmental transition in the second half of the first year. We cannot systematically rule out an interpretation of our findings based on the experience of babies in Sessions I and II or at home. However, the independence of the phenomenon from the occurrence of music at home, as well as the sometimes startling pitch-matching of babies in Session I, force us to look for more complicated epigenetic explanations. Perhaps the most plausible proposal is that, somewhat analogously to birdsong (Marler & Hamilton, 1966), the baby brings a congenital readiness to respond to pitched tones which is then adaptively modified to his experience of sounds in the first years of life. On the side of education, the research gave even more provocative answers. It may be possible that pitch-matching is usual in babies and that, for most of them, the ability is lost with the onset of language or with the failure of many environments to support its continuation. Early music education may require, not so much the building of new perceptual and cognitive structures, but rather the maintenance of capacities which, for whatever evolutionary reason, are available to most children.
REFERENCES Bandura, A., & Waiters, R. H. Social learning and personalit3, development. New York: Holt, Rinehart, & Winston, 1963. Bernstein, L. The unanswered question: Six talks at Harvard. Cambridge: Harvard University Press, 1976. Freud, S. The passing of the Oedipus-complex. In Collected papers, Vol. II. London: Hogarth, 1924. Hetzer, H., & Wolf, K. Babytests. Zeitschrift fiir Psychologie, 1928, 107, 62-104. Laufer, Z. L., & Horii, Y. Fundamental frequency characteristics of infant non-distress vocalization during first twenty-four weeks. Journal of Child Language, 1978, 4, 171-184. Marler, P., & Hamilton, W. Mechanisms of animal behavior. New York: Wiley & Sons, 1966. Meltzoff, A. N., & Moore, M. K. Imitation of facial and manual gestures by human neonates. Science, 1977, 198, 75-78, Miller, N. E., & Dollard, J. Social learning and imitation. New Haven: Yale University Press, 194 I. Ostwald, P. F. Musical behavior in early childhood. Developmental Medicine & Child Neurology, 1973, 15, 371. Piaget, J. Play, dreams, and imitation. (French edition, 1945.) New York: Norton, 1951.