It's commonly said that children are growing up too quickly nowadays. These days, it is not particularly uncommon to see children as young as six wearing designer duds, playing games on iPads, and wanting to be sexy. But could growing up too quickly have actual ramifications for their adult lives?

One researcher thought that there might be a link, at least between early sexual experiences and romantic outcomes later in life. Paige Harden, a psychological scientist from the University of Texas at Austin, used data from 1,659 brother-brother or sister-sister sibling pairs from the National Longitudinal Study on Adolescent Health. The sibling pairs were usually followed from mid-adolescence, normally at around the age of 16, to young adulthood, around age 29. Each sibling was classified as having had their first sexual experience early (before the age of 15), on time (15 to 19), or late (after the age of 19). Harden investigated whether the participants were married or lived with their partners, how many romantic partners they had, and their level of satisfaction in their current relationships.

As Harden expected, people who'd had their first sexual experience later than their peers were more likely to have attained a higher educational degree and had a higher household income. They also had fewer romantic partners in adulthood and were less likely to be married.

For those who were married or lived with a partner as adults, participants who had waited longer to have their first sexual experience were more likely to have higher levels of relationship satisfaction than their peers. This link remained even when Harden controlled for income, religiousness, educational attainment during adulthood, body mass index, attractiveness, or dating differences during adolescence.

Interestingly though, while previous research focused on the negative toll that early sexual activity can have on teens' and adults' physical and mental health, Harden's study found little difference between those who had their first sexual experience early and those who were on time. Her research indicates that late sexual activity has a protective effect, rather than early sexual activity taking a toll on lives.

Harden believes that there may be a number of reasons why those who wait longer to have their first sexual experiences have better romantic lives later on. She suggests that they may be pickier in choosing romantic partners or better-equipped to handle relationships if they enter intimate relationships for the first time. Waiting to pursue intimate relationships may also mean that they avoid early encounters with relationship aggression that could take a toll on later romantic relationships.

Earlier sexual activity is not always negative. Harden found that teens who had their first sexual experience earlier, especially those who were in relationships, were less likely to engage in delinquent behavior.

The study will be published in the upcoming issue of Psychological Science.