Cambridge Study of 130 Newborns Shows Average Sex Differences in Face Versus Object Attention Hours After Birth

Researchers at the University of Cambridge tested 130 infants within hours of birth using simultaneous video presentations of a social face stimulus and a nonsocial mechanical object. Gaze was coded by blinded observers under tightly controlled conditions that eliminated postnatal social exposure. The design directly replicated and improved upon the 2000 Connellan et al. protocol with larger sample size and objective methods.

Both sexes preferred the face overall, yet females allocated significantly more viewing time to the social stimulus while males spent proportionally longer on the mechanical display. These average differences emerged before extensive environmental input, implicating prenatal factors such as sex hormones or sex-linked genes. Group-level findings do not permit individual prediction or diagnosis.

The results converge with the same lab's recent reports of sex differences in neonatal brain structure and with elevated male prevalence in autism spectrum conditions. They indicate that biological and experiential influences interact from the outset rather than operating in isolation, moving beyond simple nature-versus-nurture framing.

Longitudinal follow-up of this cohort is required to test whether neonatal attention patterns predict later social-communication trajectories. Larger, multi-site replications that include direct hormone assays and diverse populations will clarify effect stability and generalizability.