Sex and gender uniquely reflected in children’s brain networks, study finds

New research reveals distinct functional connectivity patterns associated with biological sex and gender expression in young children’s brains, suggesting these constructs shape neural development in different ways.

 

sex and gender differences

Neurobiological correlates of sex and gender uncovered

A groundbreaking study has identified unique patterns of brain functional connectivity associated with biological sex and gender expression in children, providing new insights into how these constructs may shape neural development. The research, published in Science Advances [1], analyzed brain imaging data from over 4,700 children aged 9-10 years old to disentangle the neurobiological underpinnings of sex and gender.

“Our findings suggest that sex and gender are irreducible to one another not only in society but also in biology,” said lead author Roshni Dhamala of the University of Pennsylvania. “They appear to be uniquely represented in the functional networks of children’s brains.”

Distinct brain patterns for sex and gender  

The researchers used machine learning techniques to predict children’s biological sex and gender expression based on patterns of functional connectivity between different brain regions. They found that while sex could be classified with a high degree of accuracy, gender expression was more difficult to predict from brain data alone.

Importantly, the functional connections most strongly associated with biological sex were distinct from those linked to gender expression. Sex was preferentially associated with connectivity in somatomotor, visual, control and limbic networks. Meanwhile, the network correlates of gender were more distributed throughout the cortex.

“These results demonstrate that sex and gender, although strongly correlated, are uniquely represented in functional brain networks even at this young age,” Dhamala explained.

Implications for healthcare

In a related focus article, Drs. Nils Kroemer and Birgit Derntl of the University of Tübingen highlighted the potential clinical implications of this work. They noted that sex and gender differences exist in the prevalence and manifestation of many brain disorders, but the neural bases of these differences are poorly understood. For example, they point out that autism spectrum disorder and Parkinson’s disease are more common in males than in females, whereas depression, migraine, and Alzheimer’s disease are more common in females than in males.

“Because the sources of sex differences are poorly understood, basing research and clinical care on a one-sex-fits-all approach calls into question the validity of such an approach,” Kroemer and Derntl wrote.

“Identifying the distinct neural correlates of sex and gender may help improve clinical care by allowing for more personalised approaches.”

They emphasised that integrating sex and gender perspectives into brain research and clinical neuroscience is “long overdue” and has the potential to transform the current “one-sex-fits-all” paradigm.

The study authors acknowledged some key limitations, including the restricted age range of the sample and the fact that gender norms can vary across different social and cultural contexts. They emphasised the need for longitudinal research to track how sex- and gender-related brain patterns may change across development, particularly through puberty and adolescence.

Kroemer and Derntl outlined several challenges facing this emerging field, including the need for standardised definitions and reporting of sex and gender variables, balancing large-scale and targeted experimental studies, and carefully communicating findings to avoid misinterpretation.

“The neurosciences are just beginning to shed light on the roles sex and gender play in shaping the human brain,” they wrote. “While much work remains, this line of research has the potential to transform our understanding of brain development and improve clinical care for brain-related disorders.”

Reference:
  1. Dhamala, R., Bazinet, V., Kaczkurkin, A. N. et. al. (2024). Sex and gender are uniquely represented in the functional connectivity of the developing brain. Science Advances, 10(11). doi: https://doi.org/10.1126/sciadv.adn4202