研究：女性话多因脑部语言蛋白多

美国马里兰州大学神经学家和心理学家联合进行的一项研究显示，女性的确比男性话多，其原因是女性大脑中的“语言蛋白”比较多。此前有研究称，女性一天大概说2万个单词，比男性多出1.3万个。而这项研究是首次从语言蛋白含量角度来解释男女语言表达方面的差别。研究人员对出生四天的雌雄实验鼠的观察发现，雄性实验鼠在5分钟内发出的声音是雌性老鼠的两倍，而对其脑部检测结果显示，雄性实验鼠脑中跟语言表达相关的Foxp2蛋白含量是雌性老鼠的两倍。研究人员又对十位年龄在3到5岁的儿童脑部蛋白取样分析后发现，女孩脑中的Foxp2蛋白比男孩多出30%。马里兰州大学医学院教授麦卡锡表示，研究结果表明Foxp2蛋白是哺乳动物口头交流性别差异的神经生物因素之一。

Women do really talk more than men, a study has concluded.

American researchers found females are the more talkative sex because of a special “language protein” in the brain.

The study, compiled by neuroscientists and psychologist from the University of Maryland, concluded that women talked more because they had more of the Foxp2 protein.

The research, published in the Journal of Neuroscience, found that higher levels were found among humans that were women but in rats they were males.

Their findings come after it was previously claimed that ladies speak about 20,000 words a day – more than 13,000 more than men.

"This study is one of the first to report a sex difference in the expression of a language-associated protein in humans or animals,” said Prof Margaret McCarthy, who led the study.

“The findings raise the possibility that sex differences in brain and behaviour are more pervasive and established earlier than previously appreciated.”

In their study, the researchers attempted to determine what might make male rats more vocal than their female friends.

They separated four-day-old rats from their mothers and then counted the number of times they cried out in the “ultrasonic range”, the frequencies higher than humans can hear, over five minutes.

While both sexes emitted hundreds of cries, the males called out twice as often, they found. But when the pups were returned to the same cage as their mother, she fussed over her sons first.

According to tests compiled on the parts of the brain known to be involved in vocal calls showed the male pups to have up to twice as much Foxp2 protein as the females.

The researchers then increased the production in the brains of female pups and reduced it in males.

This led to the female rats crying out more often and their mothers showing more interest to them. In contrast, males became less “talkative”.

The researchers then tested samples from ten children, aged between three and five, which showed that females had up to a 30 per cent more of the Foxp2 protein than males, in a brain area key to language in humans.

“Based on our observations, we postulate higher levels of Foxp2 in girls and higher levels of Foxp2 in male rats is an indication that Foxp2 protein levels are associated with the more communicative sex,” said Prof McCarthy, from the university’s School of Medicine.

"Our results implicate Foxp2 as a component of the neurobiological basis of sex differences in vocal communication in mammals."