In the United States, the Food and Drugs Administration (FDA) in May 1960 approved the first contraceptive pill, colloquially 'the pill', a drug that has had a huge impact on the nation's history. Political attitudes towards human sexuality altered dramatically in the late 1960s because of young people. Although the behavior of most Americans did not change overnight, the heretofore mainstream beliefs on issues such as premarital sex, birth control, abortion, homosexuality, and pornography were openly challenged and no longer considered automatically valid. Individuals no longer feared social consequences when they expressed deviant ideas. The causes of this sexual revolution were manifold. More reliable methods of contraception and antibiotics capable of curing various venereal diseases eliminated two leading arguments against extra-marital sex. Sexologist Alfred C. Kinsey's books, "Sexual Behavior in the Human Male" (1948) and "Sexual Behavior in the Human Female" (1958), employed confidential interviews to proclaim that sexual behaviors previously deemed unusual were more common than people thought. Despite triggering a storm of criticisms, the Kinsey Reports earned him the nickname the "Marx of the sexual revolution" due to their revolutionary influence. Many men and women celebrated their newfound freedom and had their satisfactions, but the sexual revolution also paved the way to new problems. Many young people were under peer pressure to enter relationships they felt they were ill-prepared for, with serious psychological consequences. Illegitimate births ballooned, as did sexually transmitted diseases. Public health officials raised the alarm on an epidemic of gonorrhea and the emergence of the lethal acquired immune deficiency syndrome (AIDS). Because many had strong opinions on various subjects relating to sexuality, the sexual revolution exacerbated sociopolitical stratification.