奇速英语

A study has found new clues into why some people become left-handed and others become right-handed. Researchers have found that the trait, shared by about 10 per cent of people, could have something to do with our genes. The findings, published in the journal Nature Communications, identified rare variants (变体) of a gene involved in controlling the shape of cells and found them to be 2.7 times more common in left-handed people. 

While the genetic (基因的) variants were found in only a tiny amount of left-handed people, about 0.1 per cent, the researchers said the study showed the gene, called TUBB4B, could lead to someone using either the left or right side of their brains for learning language. Those who mostly use the left side of the brain when learning language tend to write with their right hand, while those who mostly use the right side of their brain become left-handed.

The study looked at the genetic data of more than 350,000 middle-aged or older adults from Britain. About 11 per cent were left-handed.

The study could throw some light on the role of genes leading to right or left handedness, one of the lead authors, Clyde Francks said. But despite the genetic link found in the study, for most people, whether or not they became left-handed could purely be down to chance, he added.

Over the centuries, many cultures have looked down upon left-handedness and tried to force them to become right-handed. In English, the word “right” also means “correct” or “proper.” The word “sinister” came from a Latin word meaning “on the left side.” Even today, the Italian word for “left” is “sinistra”. And a “left-handed compliment” means an insult covered up as praise.

The number of left-handed people varies across the world. There have been found to be fewer left-handed people in Africa, Asia and the Middle East compared to Europe and North America, Francks said. He said in many countries, naturally left-handed kids are still made to use their right hand to write and draw.