Infant preferences for infant-directed versus noninfant-directed playsongs and lullabies

Each of 15 mothers was recorded singing a song of her choice to her 4- to 7-month-old and singing the same song alone. Adult raters were very accurate at distinguishing infant-directed from infant-absent versions, and the former were independently rated as more loving than the latter. Most of the songs were consistently classified as either playsongs or lullabies. The infant-directed playsongs were rated as relatively more rhythmic than the infant-directed lullabies, in comparison to the infant-absent versions. These results suggest that playsongs and lullabies may be distinct and used to communicate different information. Infant preferences were tested for three playsong and three lullaby pairs in a preferential looking paradigm. Infants preferred the infant-directed over infant-absent versions for five of the six pairs. Furthermore, the degree of preference was correlated with the adult ratings of loving tone of voice. The results indicate that mothers modify their singing in the presence of their infants, that infants attend to these changes, that playsongs and lullabies are likely distinct musical styles differing in their rhythmic quality, and that what adults perceive to be a loving tone of voice is highly salient to infants.