Human sexuality is the way people experience and express themselves sexually. This involves biological, erotic, physical, emotional, social, or spiritual feelings and behaviors. Because it is a broad term, which has varied over time, it lacks a precise definition. The biological and physical aspects of sexuality largely concern the human reproductive functions, including the human sexual response cycle. Someone's sexual orientation can influence that person's sexual interest and attraction for another person. Physical and emotional aspects of sexuality include bonds between individuals that are expressed through profound feelings or physical manifestations of love, trust, and care. Social aspects deal with the effects of human society on one's sexuality, while spirituality concerns an individual's spiritual connection with others. Sexuality also affects and is affected by cultural, political, legal, philosophical, moral, ethical, and religious aspects of life.
Interest in sexual activity typically increases when an individual reaches puberty. Opinions differ on the origins of an individual's sexual orientation and sexual behavior. Some argue that sexuality is determined by genetics, while others believe it is molded by the environment, or that both of these factors interact to form the individual's sexual orientation. This pertains to the nature versus nurture debate. In the former, one assumes that the features of a person innately correspond to their natural inheritance, exemplified by drives and instincts; the latter refers to the assumption that the features of a person continue to change throughout their development and nurturing, exemplified by ego ideals and formative identifications.
Evolutionary perspectives on human coupling, reproduction and reproduction strategies, and social learning theory provide further views of sexuality. Sociocultural aspects of sexuality include historical developments and religious beliefs. Some cultures have been described as sexually repressive. The study of sexuality also includes human identity within social groups, sexually transmitted infections (STIs/STDs), and birth control methods.