Study finds brain differences based on gender at birth and constant in early childhood

A new study published in gender differences biology revealed that structural differences between men and female brains exist since birth and remain relatively unchanged during the first month of life, underlining the important role of prenatal biological factors in the formation of early development.

The study, conducted by scientists from the University of Cambridge as part of the developing human work Connectome, analyzed the brain scans of 514 full, healthy newborn-278 boys and 236 girls in the first 28 days of life.

Using magnetic resonance imaging (MRI), the researchers found that male infants had larger total volumes of the brain, a pattern that is aligned with findings in older children and adults.

However, after adaptation to the overall brain size, female infants were found to have more gray matter, the part of the brain responsible for processing information, while male infants had more white matter, facilitating communication between the brain areas.

Head writer Yumnah Khan, a PhD student at the University of Cambridge, said the findings cause long -term assumptions that such sex -based differences in the brain are largely the result of social or environmental influences.

“Several gender differences in the middle of the brain are already present from birth, indicating that prenatal factors play an important role in starting sex differences in the brain,” Khan told Psypost.

Exploring the structural differences of the brain

MRI scans have revealed specific areas of the brain where the sexes were different. Female infants had relatively larger tumors in the Corpus Callosum, the bridge between brain hemispheres and the parachic round, which are connected to memory.

Meanwhile, male infants have shown larger tumors in the middle and lower time Gyri, areas associated with visual and acoustic treatment.

Specifically, these differences remained stable throughout the first month of life, suggesting that they were created before birth and not shaped by early postnatal experiences.

“We found very interesting that many of the sex differences previously observed in older children and adults were already present at birth,” Han said. “This emphasizes that these differences exist from the beginning of life and probably emerge prenatal.”

Impact on Neurodevelopment Research
The findings have a significant impact on understanding why some neurological and psychiatric conditions – such as autism, ADHD and depression – occur more frequently or occur differently in men and females. Researchers say these conditions can be linked to early structural differences in the brain, offering a possible path to previous recognition and targeted interventions.

Han emphasized that the interest in gender differences is not only academic but also practically important.

“The best understanding of gender differences, their underlying causes and the timing of their appearance can explain why some disorders affect males and females differently.

ATTENTION UNDER OBLIGATION

Despite the findings, the researchers were careful to warn the excessive interpretation of the results. The differences observed are average differences in large groups and do not suggest that male and female brains are fundamentally or universally different in operation.

“It is important not to overestimate or exaggerate the differences,” Han explained. “The brain is not ‘sexually dimorphic’ as reproductive organs. Male and women’s brains are more similar than they are different.”

The study did not investigate whether the observed structural differences translate into behavioral or cognitive differences, nor do they explore the exact causes – either genetic, hormonal or environmental – from these early brain differences.

“There is still much more to reveal,” Han said. “We now have to determine whether these structural differences are linked to the behavior, knowledge or future development effects. Understanding the origin and impact of these differences is the next crucial step.”

This research marks one of the most detailed research on gender differences in the neonatal brain, offering a fundamental understanding of the way men and female brains begin to deviate – if only slightly – from the early days of life. It also adds to the growing body of evidence that biological sex plays a role in brain development from the early stages, long before social and cultural influences.