Newborn girls show stronger attention to faces, study suggests biological role in early sex differences

Researchers report that, as a group, female newborns display greater interest in faces than male newborns, a pattern the authors say is likely rooted in biology and bears on the long-standing nature versus nurture debate.

Researchers studying visual attention in newborn infants say they have found measurable differences between the sexes that point to a biological contribution to early behaviour. The study compared groups of newborn babies and observed that, overall, girls spent more time looking at faces than boys did, a pattern the authors interpret as unlikely to be explained solely by postnatal socialisation.

Study and findings

According to the report, the team measured infants’ responses to visual stimuli soon after birth and found consistent differences in face-directed attention when comparing groups by sex. The authors argue these group-level disparities are best understood as reflecting innate factors rather than experience accumulated after birth, though the study does not claim that all behavioural differences are determined biologically.

Implications and limitations

The researchers and commentators caution that group differences do not determine the behaviour of any single child, and that early social and environmental influences remain powerful. The findings add a piece of evidence to debates about how much of sex-differentiated behaviour arises from biology, but the authors acknowledge that disentangling genetic, prenatal and early postnatal influences remains complex.

Context in the broader debate

Nature-versus-nurture questions have long animated scientific and public discussions about sex differences in behaviour. This study does not resolve that debate, but its authors say that demonstrating early, group-level differences in newborns strengthens the case for biological contributions while leaving room for substantial shaping by experience as development proceeds.

Further research needed

The report concludes that additional work will be needed to replicate the findings, explore underlying mechanisms, and track how early attentional biases interact with caregiving and cultural factors to shape later social and cognitive development. Such follow-up studies, the authors suggest, will help clarify how early differences contribute to the diverse outcomes seen across individuals.