Explaining why women have a smaller brain than men

Women have smaller brains than men because of the effects of female estrogen hormones during human evolution.

Why do women have brains smaller than men?

A group of researchers at the Chinese Academy of Sciences said that gender dimorphism in brain size is a common feature among primates . It is found in humans, apes and some other monkey species. The outstanding feature is that males often have larger brains than females.

Women have smaller brains because of the effects of estrogen hormones.(Photo: Istock)

Research by scientists from Cambridge University, UK conducted in 2014, the average brain detection of men is 13% larger than that of women . The cause of this phenomenon has confounded the scientific community for many years.

In the latest research report published in the journal BMC Evolutinary Biology in June, Chinese researchers examined the effects of estrogen (oestradiol) female hormones on up to seven genes involved in the formation of human brain size and Other primates such as chimpanzees and brown monkeys.

Results showed that four of these genes were linked to estrogen hormones . Estrogen significantly inhibits the expression of four affected genes, related to the formation of brain size.

" We have demonstrated that estrogen regulates the activity of four genes that regulate brain size. This inhibitory effect creates differences in male and female brain size in humans and non-human primates. Sex hormones play an important role in primate evolution of primates , "Ibtimes quoted the study authors.

The authors argue that the natural selection process is likely to cause women's brain size to be smaller than men.

" The difference in the social roles of men and women leads to different selective pressures in the evolutionary process. More evidence is needed to test this hypothesis."