Scientists have found that boys born in winter are more often left-handed than those born in summer. Austrian scientists surveyed 13 thousand adults. It turned out that 8.8% of men and 7.5% of women are left-handed. What is interesting: 8.2% of left-handers were born from February to October, 10.5% - from November to January. There is an assumption that the seasonality of left-handed birth is related to the level of left-handed hormones. Scientists say high testosterone levels affect left-handedness. The longer the child, the higher the level of this hormone. In other words, babies who are in the womb in the winter get more testosterone.
This sentence explains the birth of only left-handed boys. Although it is possible that the hormone rises and when carrying girls. Scientists say that testosterone is able to inhibit the development of the left hemisphere of the brain, which is essential for right-handers.
