Early Research on Identical Twins
Francis Galton was an expert on genetics and he made the first scientific attempt to study identical twins. Galton also created the statistical concept of correlation, which describes the relationship between different factors or variables. He was the first person to apply statistical methods to the study of human differences. In one study, Galton observed that 19 out of 35 sets of identical twins had differences in personality. After looking at their health records, he concluded that a serious illness or accident were the only causes which could adequately explain why identical twins behaved differently.
According to Galton, which causes could adequately explain differences in personalities of identical twins? Choose 2 correct answers.
