Exploring variation in infants’ preference for infant-directed speech: Evidence from a multi-site study in Africa

This preference has been linked to infants’ language processing and word learning in experimental settings, and also correlates with later language outcomes. Recently, the cross-cultural consistency of infants’ IDS preference has been confirmed by large-scale, multisite replication studies, but conclusions from these studies were primarily based on participants from North America and Europe. The current study addressed this sampling bias via a large-scale, multisite study of infants (3-15 months) across communities in Africa. We investigated whether participants showed a preference for IDS over ADS, and if so, whether the magnitude of their preference differs from effects documented in other populations of infants. Across six sites (total N = 200), we observed a preference for IDS βIDS vs. ADS = 0.06), suggesting that infants look on average 6% longer on the IDS trials than the ADS trials. There was no significant difference between African infants in this study and a method-matched subsample of infants from prior studies of IDS preference. This study provides new evidence on the generalizability of IDS preference and looking-time methods more broadly, while also highlighting some of the challenges of global big team science.