identical twins

Heavy drinking is associated with a number of problems, but one surprisingly common problem involves not remembering large chunks of time. Called alcohol-induced blackouts, these memory losses were reported by more than 39 percent of women and more than 50 percent of men studied by researchers from Washington University School of Medicine in St. Louis and the Queensland Institute on Medical Research in Australia. The researchers also found that genetic factors play a big role in whether or not a person blacks out after heavy drinking. Studying more than 2,300 pairs of Australian twins, the research team was able to determine that more than 50 percent of the risk of blacking out seems to be controlled by genetic factors, and the role of genes is even greater in people who report blacking out multiple times.