A new study published on NCBI on 5th March 2019 done by Wheelock. et. al. states that during human gestation itself the sexual dimorphism ends up emerging in functional brain systems. The study focused on the way individual genes were transcribed in the human brain (from the prenatal period to adulthood).
During the study, MRI scans of pregnant mothers showed a clear difference between the brains of babies of different genders. Female fetus brains had differences in the subcortical and cortical structure connectivity in the brain. Female fetuses were also found to have greater prefrontal cortical brain volume.
From the study, it was found that it was the prenatal period where the difference in gene transcription in the human brain among male and female brains was seen. It was also seen that the IGF2 gene (related to cognition) showed transcriptional male/female differences in the prenatal period. But the transcriptional difference of this gene was nonexistent among adults of different genders.
It showed that gender is not just a social construct rather the differences start to show in the prenatal period itself. If the gender being only a social construct theory was true then the differences must have been present in the adult brains after the socialization, which evidently was not found.
