Do you know why your teen kids drink alcohol, smoke, take drugs and have sex? All these make them feel maturer than they really are, as revealed by a Canadian research. With getting older, teens deepen the gap between their real age and their self-perceived age.

The team at the University of Alberta in Edmonton and the University of Victoria investigated a random sample of about 700 adolescents from a medium-sized North American city and questioned them about dating, sexual experience, smoking, alcohol and drug use. The subjects of both sexes, aged 12 to 19, were also required to express how old they felt in comparison to their same age counterparts. As a rule, teens regarded themselves older than their chronological age was.

"We found that specific behaviors do have an effect on adolescents' self-perceived age. For example, having an older dating partner seems to give a teen a higher subjective experience of age.", said co-author Kelly Arbeau, a doctoral student in psychology at the University of Alberta.

Sexual activity, especially begun at an earlier age, boomed the teens' subjective experience of age (SEA). "Sexual experience is unequivocally the realm of adult behavior. So, when teens are having sex and their peers aren't, it can make them feel more adult, more mature than their non-experienced counterparts." explained Arbeau.

Smoking, heavy drinking and increased drug use were also linked to an older SEA. In their 20s, people feel about the age they are or slightly older, but after age 30 and into old age, individuals tend to have an SEA that is younger than their chronological age. Teenage is the only point in the lifespan during which everybody consistently feels older than his/her real age. The research confirmed the popular wisdom that girls mature earlier than boys: girls were found more likely to experience higher SEA than boys did. This explains why companies rather target teen girls than teen boys with "adult" products.