私醫聯招 英文歷屆試題｜第 191 題

Various research centers are studying identical twins in order to discover the "heritability" of behavioral characteristics—that is, the degree to which a trait is due to genes instead of environment. They have reached some startling conclusions. One study found, for example, that optimism and pessimism are both very much influenced by genes, but only optimism is also affected by environment. According to another study, genes influence our coffee consumption, but not consumption of tea. Anxiety seems to be 40 to 50 percent heritable. Another study tells us that happiness does not depend much on money or love or professional success; instead, it is 80 percent heritable! Among the traits that appear to be largely heritable are shyness, attraction to danger (thrill seeking), and choice of career.