New York: If your friends say that you have changed after you started dating, they are right. A new study says that non-dating teenagers who start dating turn more similar to their romantic partners than to friends in behaviour — in this case, in alcohol abuse.

‘The results confirm what most friends complain about — romantic partners are a distraction from friendships,’ said one of the study authors Professor Brett Laursen from Florida Atlantic University.

‘It also is a stark reminder how the peer social world changes during adolescence. Same-sex friends become less important and romantic affiliations become more important,’ Laursen added.

Similarity is the hallmark of adolescent friendships and not coincidently, most single adolescents report friends to be among their most important relationships.

However, the start of a new romantic relationship alters the balance of close relationships.

As romantic relationships surpass friendships in terms of importance, adolescents are inclined to change to become more similar to their romantic partners, even if it means that differences arise with friends.

‘Friends no longer shape drinking habits the way they used to. Romantic partners now dictate terms,’ Laursen said.

In the first part of the study, participants (662 girls, 574 boys) ranging in age from 12 to 19 years, nominated friends and romantic partners, and completed a measure of alcohol abuse.

Friends with romantic partners were less similar on rates of alcohol abuse than friends without romantic partners.

The study was published in the journal Developmental Psychology.