Those conducting the study speculated that fewer girls say they have ever had sex because girls viewed teenage parenthood as more of a problem than boys. Among boys and girls who had experienced sexual intercourse, the proportion of girls and boys who had recently had sex and were regularly sexually active was the same. The girls were less likely to state that they ever had sex than adolescent boys. One study from 1996 documented the interviews of a sample of junior high school students in the United States.
The prefrontal cortex area of the human brain is not fully developed until the early 20s or about age 25. Several brain regions in the frontal lobe of the cerebral cortex and in the hypothalamus that are deemed important for self-control, delayed gratification, risk analysis, and appreciation are not fully mature. The risks are higher for young adolescents because their brains are not neurally mature.
Contraceptives specifically reduce the chance of teenage pregnancy. The risks of sexual intercourse include unwanted pregnancy and contracting a sexually transmitted infection such as HIV/AIDS, which can be reduced with availability and use of a condom or adopting other safe sex practices. Sexual activity in general is associated with various risks. Sexual interest among adolescents, as among adults, can vary greatly, and is influenced by cultural norms and mores, sex education, as well as comprehensive sexuality education provided, sexual orientation, and social controls such as age-of-consent laws. Sexual interest may be expressed in a number of ways, such as flirting, kissing, masturbation, or having sex with a partner. Interest in sexuality intensifies during the onset of puberty, and sexuality is often a vital aspect of teenagers' lives. Adolescent sexuality is a stage of human development in which adolescents experience and explore sexual feelings.