Abstract Darwin (1871) noted that the human musical faculty 'must be ranked amongst the most mysterious with which he is endowed'. Indeed, previous research with human infants and young children has revealed that we are born with variable musical capabilities. Here, the adaptive purpose served by these differing capabilities is discussed with reference to comparative findings regarding the acoustic behavior of nonhuman primates. The findings provide evidence supporting Darwin's hypothesis of an intermediate stage of human evolutionary history characterized by a communication system that resembles music more closely than language and possibly acting as a precursor for both current language and music.
Abstract Behavioral preferences for consonance over dissonance were tested in hearing infants of deaf parents and in hearing infants of hearing parents when they were 2 days old. Using a modified visual‐fixation‐based, auditory‐preference procedure, I found that both 2‐day‐old infants of deaf parents and those of hearing parents looked longer at a visual stimulus when looking produced the original version of a Mozart minuet as opposed to a version altered to contain many dissonant intervals. The relative magnitude of such preference did not significantly differ whether their parents were deaf or hearing. Infants prefer consonance over dissonance, and the preference is present from birth and is not dependent on any specific prenatal or early postnatal experience.
In the present study, eight children with Williams syndrome were observed every 2 weeks between 6 months and 30 months of age when interacting with their mothers. When the collected data were transcribed in terms of both linguistic and motor activities, overall delay was found in terms of the onset of canonical babbling, first words, as well as various motor milestones in every child. The degree to which acquisition of each of the milestones was delayed was individually variable. Nevertheless, the onset of hand banging was found to be an indicator that predicted the onset of canonical babbling consistently among the children. Once canonical babbling was produced, moreover, the onset of first words was recorded during a following 2 to 3 month period. These findings appear to indicate the possibility that development of the motor ability to perform such rhythmic motor activity as hand banging acted as a control parameter for production of canonical syllables in the children.
This study reports on co‐occurrence of vocal behaviors and motor actions in infants in the prelinguistic stage. Four Japanese infants were studied longitudinally from the age of 6 months to 11 months. For all the infants, a 40 min sample was coded for each monthly period. The vocalizations produced by the infants co‐occurred with their rhythmic actions with high frequency, particularly in the period preceding the onset of canonical babbling. Acoustical analysis was conducted on the vocalizations recorded before and after the period when co‐occurrence took place most frequently. Among the vocalizations recorded in the period when co‐occurrence appeared most frequently, those that co‐occurred with rhythmic action had significantly shorter syllable duration and shorter formant‐frequency transition duration compared with those that did not co‐occur with rhythmic action. The rapid transitions and short syllables were similar to patterns of duration found in mature speech. The acoustic features remained even after co‐occurrence disappeared. These findings suggest that co‐occurrence of rhythmic action and vocal behavior may contribute to the infant's acquisition of the ability to perform the rapid glottal and articulatory movements that are indispensable for spoken language acquisition.
AbstractThis study is concerned with ways in which children with Williams syndrome (WS), a rare neurodevelopmental disorder arising from a hemizygous deletion in chromosome band 7q11.23 including the gene for elastin (ELN) and approximately 20 surrounding genes, are affected by social mores of vastly differing cultures: the United States and Japan. WS presents a compelling model for the investigation because its genetic phenotype is well defined and results in an uneven cognitive profile as well as a social phenotype typical of the syndrome including overt over‐friendliness toward strangers. While a number of research groups have been studying the cognitive strengths and weaknesses of individuals with WS in various countries, there have not been studies to date that explore the social phenotype in WS across different cultures. This study examines the ways in which social behavior in WS, stemming from specific genetic underpinnings, might be mediated by cultural expectations. We conducted a cross‐cultural study using an instrument that measures aspects of sociability commonly found among people with WS. Quantitative analyses revealed a significant effect of diagnostic category in that in both countries, children with WS were rated as significantly higher in global sociability and more likely to approach strangers than were their normal counterparts. There was also an effect of culture, in that regardless of category, WS and normal children in Japan were rated lower than their counterparts in the US. We suggest that the excessively social phenotype of children with Williams syndrome, although markedly present across cultures, appears to vary in its intensity by culture. This is an intriguing illustration of interactions between nature and nurture.
