Mommy and Mama: Parental Language Input from Mother-Mother Couples

In families headed by mother-father dyads in the U.S., fathers provide less input to their infants and use less parentese, an infant-directed speech register with higher pitch, slower tempo, and exaggerated intonation, than mothers. In this observational study, we examined input from mother-mother-headed families to determine whether similar imbalances occur among caregivers of the same gender, and whether within-dyad differences are related to gender/sex or alternative factors such as caregiver roles. Daylong Language ENvironment Analysis (LENA) recordings and questionnaire data were collected from twenty-one 3 to 24-month-old infants and their English-speaking mother-mother parents. LENA recordings were manually annotated and transcribed. Mother-mother couples exhibited imbalances in both parentese use and overall talk, suggesting that variability in language input is not due solely to gender/sex. While there was no relation between overall amount of talk and caregiving responsibilities, there was a positive correlation between the rate of parentese use and caregiving responsibilities. Furthermore, the degree to which mothers differed in their use of parentese was related to the degree to which they differed in caregiving responsibilities. Together, the present results suggest that within-dyad differences in parentese use may be attributed to differences in parents’ involvement in caretaking, rather than gender/sex. Conversely, differences in the amount of talk may be more closely related to gender/sex but are likely subject to additional influences. These results support a functional-social theory of parental language behavior that emphasizes caregiver roles rather than gender-social or evolutionary-biological theories.