PIP: In 1976 326 students, 149 men and 177 women, were asked to fill a questionnaire in 2 U.S. campuses to analyze interpersonal factors related to contraceptive practices. 86% of students were white, belonged to the middle class, and were of average age 19.6. The questionnaire carried questions related to demographic problems, personality, and sex behavior. Of 326 students, 113 were virgin, and 213 sexually active. Sexual activity tended to increase with age, with a notable acceleration between 16-25 for women, and 14-18 for men. About half of the participants stated not to have used contraception at their first sexual experience; for the others the methods used were coitus interruptus, or condom. In case of a lasting relationship the method used the first time was later changed for a more reliable one. Major predictors of contraceptive method were the frequency of sexual relations, the method used the first time, age, and knowledge of the physiology of reproduction. 77% of couples who lived together used the pill. Results showed that use of a reliable contraceptive method depended much more on the type of relationship, than on personality or characteristics of the individual.