Sex education greatly boosts the likelihood that teens will delay having intercourse, according to a new study that is the first of its kind in years. Male teens who received sex education in school were 71 percent less likely — and similarly educated female teens were 59 percent less likely — to have sexual intercourse before age 15. Males who attended school, meanwhile, were 2.77 times more likely to rely upon birth control the first time they had intercourse if they had been in sex-education classes.