Don’t date your friends’ exes. That’s the unspoken golden rule of high-school romances. But while this might be a good habit for maintaining friendships, researchers in Northeastern’s Network Science Institute recently found that not dating your friends’ exes actually increases the likelihood that teenagers will be exposed to sexually transmitted infections compared to dating people at random.
“Adolescents are about 75 percent less likely to date someone if that person dated their friend in the past,” says Cassie McMillan, an assistant professor and researcher in the Network Science Institute who co-authored the findings, which were published in the journal Social Networks.
Accounting for that statistic, McMillan and her team found that STI exposure among high schoolers is not merely a numbers game, as common sense would have it. In other words, transmission is not as simple as saying that teenagers who have sex with more people are more likely to contract STIs.