Girls and boys are equally social at birth.

This finding, based on my team’s synthesis of six decades of research, may come as a surprise. Gender differences in adults’ social sensitivity are famous. Women outperform men at recognizing faces and emotions, and they score modestly higher on measures of empathy. They are likelier to take jobs working with people, such as in teaching and health care, whereas men are likelier to choose jobs working with “things,” such as in engineering or plumbing.

But how early do these differences emerge, and are they a matter of evolution or social learning? For years, some theorists have argued the former: that the difference is innate, built into the brain hardware of girls and boys through Darwinian selection. But this perspective relies almost exclusively on just one high-profile, yet deeply flawed, study of 102 newborns.

Mining the neonatal research trove

Realizing that psychologists have been studying newborns’ social orientation for decades, my team of neurobehavioral researchers and I set out to collect all the data – every published study that has compared boys’ and girls’ attention to social stimuli in the first month of life. Our goal was to better test the hypothesis of an inborn gender difference in attention to, or interest in, other people.

Our study was a systematic review, meaning we searched through every published report indexed in both medical and psychological databases from the 1960s onward.

We cast a wide net, looking for any research that measured newborns’ attention to or preference for human faces or voices and that reported the data separately by gender. Importantly, we did not limit our search to the terms “gender difference” or “sex difference,” since these would bias the collection by potentially excluding studies that failed to find boy-girl differences.

As expected, we unearthed dozens of studies comparing newborn boys and girls on social perception: 40 experiments reported in 31 peer-reviewed studies and involving nearly 2,000 infants. The majority of studies measured the amount of time newborns spent looking at faces, either at a single face or comparing a baby’s preference between two faces of differing social value, such as their own mother versus a woman who was a stranger.

Our data collection was large enough that we were able to carry out meta-analysis, which is a statistical method for combining the results of many studies. Meta-analysis essentially turns many small studies into a single large one. For studies measuring neonates’ looking time at faces, this included 667 infants, half of them boys and half of them girls.

The result was clear: nearly identical social perception between baby boys and girls. There was no significant difference between genders overall, nor was there a difference when we focused only on studies measuring babies’ gaze duration on a single face, or only on studies measuring babies’ gaze preference between two different faces.

Our search also netted two other types of studies. One focused on a remarkable behavior: newborns’ tendency to start crying when they hear another baby cry. An early study found this “contagious crying” to be marginally more common in girls. But when we performed meta-analysis on data across nine contagious-crying experiments, including 387 infants, there was again no solid evidence for male-female difference.

The last dataset we analyzed compared babies’ orientation to both social and inanimate objects using a newborn behavior assessment scale developed by legendary pediatrician T. Berry Brazelton. Across four studies involving 619 infants, girls did pay somewhat greater attention to the social stimuli (a human face or voice), but they also paid more attention to the inanimate stimuli (a ball or the sound of a rattle).

In other words, girls in this test seemed a bit more attuned to every type of stimulus, perhaps due to a general maturity advantage that they hold from fetal development through puberty. But there was nothing special about their interest in people, according to the Brazelton assessment.

Boys, too, prefer faces

Our findings align with other well-designed studies, including one finding that 5-month-old boys and girls equally prefer looking at faces over toy cars or other objects, and another finding that 2-month-old boys actually perform better than girls at detecting faces. So taken together, current research dispels a common myth that girls are innately “hardwired” to be more social than boys in early life.

The truth is that all babies are wired for social engagement at birth. Boys and girls are both primed to pay attention to human faces and voices, which, after all, belong to those who will keep them fed, safe and comforted.

Despite their best intentions, most parents cannot help but stereotype their infants by gender and begin treating boys and girls differently early on. Presuming that sons are already less social is not a recipe for remedying this bias. Our research can help dispel this myth, giving every child, male or female, the best possible start for connecting with and caring about other people.

Lise Eliot receives research funding from the Fred B. Snite Foundation.