Newborn Girls Show Preference for Faces Over Objects Hours After Birth, Study Finds
Research suggests potential early behavioral differences between sexes, though underlying causes remain debated.
Behavioral differences between newborn boys and girls may be observable just hours after birth, according to a new study by researchers at the University of Cambridge. The study, which presented 33-hour-old infants with videos of a human face and an animated Newton's cradle, found that girls spent proportionally more time looking at the face compared to boys.
While both sexes looked at the face longer than the Newton's cradle, girls exhibited a statistically significant preference for the human face. Boys, in contrast, did not show a notable difference in looking time between the two videos. The researchers interpret this as an early indication of girls' preference for social stimuli.
The findings raise questions about the balance between nature and nurture in shaping sex-based behaviors. Researchers speculate that prenatal factors, such as varying sex hormone levels like testosterone during fetal development, could influence these early differences. Another possibility proposed is that girls may experience slightly faster cognitive development, enabling them to process visual information, such as faces, more efficiently.
However, the study acknowledges limitations. It did not track the infants beyond the initial observation period, making it impossible to determine if these early attention differences persist or predict later behavioral patterns. Furthermore, the study notes a contradiction with a 2025 review of existing research, which found no significant difference in newborn boys' and girls' fixation on human faces. The review also found no discernible difference in "contagious crying" between the sexes in response to another infant's distress.
Researchers also caution that subtle aspects of gender socialization, even within the first few days of life, could play a role, though they consider this impact likely minimal. They also point out that the visual characteristics of the videos themselves—their color, motion, and composition—could have influenced the results, and they cannot entirely rule out that a non-social visual feature drove the observed difference.