Profiles of Early Cognitive and Language Development: Links to Early-Life Factors

The first years of life are characterized by pronounced advances in cognitive and language abilities, yet children differ markedly in the pace and pattern of this development. This study addresses gaps in understanding how a broad range of early-life factors relate to such heterogeneous developmental profiles during infancy. Using longitudinal data from 911 infants in the Little in Norway study, cognitive and language abilities were assessed at 6, 12, and 18 months with the Bayley Scales of Infant and Toddler Development. Longitudinal latent class analysis identified three subgroups: “Rapid learners” (23.5%), “Typical learners” (64.3%), and “Delayed learners” (12.2%). Multinomial logistic regressions tested whether early-life factors reflecting prenatal growth, parental socioeconomic status, parental mental health and stress, and mother-infant interactional quality predicted class membership. As expected, higher paternal education increased the likelihood of belonging to the “Rapid learners” class relative to the “Typical learners”, whereas better mother-child interactional quality distinguished “Rapid learners” from “Delayed learners”. By examining diverse prenatal, family, and social influences, including paternal characteristics often overlooked in prior research, this study provides new insights into the origins of individual differences in early cognitive and language development.