It makes a village: child care and prosociality

We examine the relationship between allomaternal care (i.e., care for children by individuals other than the mother) and prosociality (reciprocity and altruism). Motivated by ethnographic evidence of a positive association between allomaternal care and societal trust across cultures, we design an economic experiment to measure the relationship between allomaternal care and cooperative behavior among 820 participants in small scale societies of the Solomon Islands. Our results show that receiving help with child care predicts higher levels of reciprocity towards the helper. This relationship remains robust for mothers even after accounting for participant fixed effects, for the nature of the relationship between mother and helper, and for other forms of mutual assistance. Moreover, help from non-relatives is associated with altruism toward strangers, suggesting a novel channel for the development of impersonal prosociality. Strengthening the case for the importance of allomaternal care for human development, we report suggestive evidence of potential socio-cognitive benefits to children who receive care from non-relatives (based on daylong recordings of 197 children analyzed using a multilingually-trained neural network), as well as societal-level benefits in terms of economic growth.