Final answer:
Sexual activity before turning 18 is associated with problem behavior and negative impacts on mental health.
Step-by-step explanation:
Sexual activity before turning 18 is associated with problem behavior, including alcohol and substance use, poor academic achievement, and delinquent activity, as well as having a larger number of sex partners compared to peers.
Research studies have shown that early sexual activity during adolescence can lead to a higher likelihood of engaging in other unhealthy behaviors such as smoking, drinking alcohol, and early involvement in sexual activity.
Early sexual activity can also have negative impacts on mental health, including poor body image and low self-esteem.