Twenty-one years ago, a young Australian geneticist named Nick Martin published a paper in Proceedings of the National Academy of Science (83:4364-8, 1986) that described a curious sideline to his regular work on the epidemiology of disease in twins. The study, which Martin coauthored with his mentor Lyndon Eaves, probed the transmission of social attitudes among more than 4,500 pairs of fraternal and identical twins. The results suggested that genetic factors, rather than cultural ones, were mostly responsible for family resemblance in social attitudes.












