A recent study published in the journal Biology of Sex Differences suggests that differences in how boys and girls pay attention may be present from birth. Researchers at the Rosie hospital in Cambridge observed 130 newborns, aged between eight hours and three days, as they watched two side-by-side videos: one of a young woman’s face and another of a Newton’s cradle toy. Using an eye-tracking device, scientists monitored where the babies looked. Both boys and girls showed more interest in the video of the woman’s face than in the swinging toy, but girls spent a larger proportion of their time looking at the face compared to boys. Because the babies were only a day or two old, the researchers believe that cultural or social influences are unlikely to explain the observed differences. Instead, they suggest that biological factors—such as genetic differences or exposure to varying levels of testosterone in the womb—may be responsible. Yumnah Khan, a PhD student at the University of Cambridge’s Autism Research Centre, noted that these findings indicate some differences in attention may be present very early in life, though they are small in scale. It is important to note that the study highlights average differences between groups of boys and girls, not that all boys or all girls behave the same way. There was considerable variation within each group, and the researchers emphasized that small differences at birth are unlikely to determine how children learn or develop. However, they could contribute to broader patterns, such as girls generally speaking earlier and developing certain social skills at a younger age than boys. Khan proposed that if girls show a greater interest in social interactions from birth, this might help them develop these skills more quickly, though this remains a hypothesis. Further research following these babies into early childhood could provide more insight. The Cambridge team is also investigating whether early differences between the sexes could influence susceptibility to certain neurodevelopmental or psychiatric conditions. For example, autism and ADHD are more commonly diagnosed in males, while anxiety and depression are more frequently seen in females. Earlier studies have also found average differences in brain structure at birth between boys and girls. These differences are thought to be influenced by hormones in the womb, particularly testosterone, which male fetuses are exposed to at more than twice the level of female fetuses during the first and second trimesters.