A number of sexological studies have attempted to relate the orgasmic capacities of women to a host of other factors, such as family background, attitudes towards parents, and personality structure. In recent times the most ambitious studies of this sort were carried out by L. M. Terman. The first involved a 6 large sample of married women (and their husbands), predominantly middle-or upper middle-class in California. The second study was also based on a California sample and made use of wives who were either highly intelligent themselves or married to intelligent husbands. One intention was that the second study would provide an opportunity to cross validate any findings that emerged from the first. These studies are discussed by Fisher in “The Female Orgasm”.