【英语时差8,16】红头发人的抗痛力-上（在线收听）

 We redheads are well known for our fiery tempers. Now it seems there's scientific backing for our ginger whingeing as well. Scientists in the United States studied a group of 144 dental patients almost half of whom had red hair. They found that the red-haired group were more sensitive to pain and as a result were twice as likely to avoid visiting the dentist. Previous research had shown that gingers were more resistant to the effects of local anaesthesia than people with other hair colours. The scientists say that this red-haired sensitivity to pain stems from the actions of a gene called MC1R. This is responsible for the production of melanin which gives skin and hair its colour. In about five percent of white people the gene is mutated leading to freckles, fair skin and red hair. Researchers say there are some receptors of this gene in the brain and that this could affect pain sensitivity.