Scientists at the University of Maryland School of Medicine (USA) have investigated whether there are differences based on sex in the expression of the Foxp2 gene , involved in the development of language in humans and in oral communication in birds and other animals. As they conclude in The Journal of Neuroscience , during childhood, the protein encoding this gene is present in greater amounts in men than in women in the regions of the cerebral cortex related to language . This could explain why, as has been extensively documented, girls tend to speak earlier and with a more complex vocabulary than boys their own age.
Interestingly, the same studies in four-day-old rats showed very different results: Males screamed louder than females when separated from their mothers and siblings. And they produced twice as many vocalizations in the same period of time (five minutes). By comparing their brains with those of females, the scientists found they had more Foxp2 protein in areas associated with knowledge, emotion and vocalization. In addition, the result of their "insistent" call was that the mothers rescued them before the females to return them to the nest.
" This is the first study that shows a sexual difference in the expression of proteins associated with language in humans or animals," says Margaret McCarthy, co-author of the study.
