Parental Monitoring During Early Adolescence Deters Adolescent Sexual Initiation: Discrete-Time Survival Mixture Analysis.:
An increase of parental monitoring across ages is accompanied with a decrease of sexual risk. The continual high level of parental monitoring from ages 14 to 16 also mitigated the risk of engagement in substance use and delinquent behaviors from ages 14 to 23.
So if you pay attention to what your kids are doing, they will delay sexual activity and be less likely to use drugs or engage in delinquent behaviours.
Well duh.