Everyone knows teen behavior is highly influenced by their

[Ella_Michigan]

Everyone knows teen behavior is highly influenced by their friends, but a new study finds even a friend's parents can influence whether or not a teen drinks or uses drugs.

If the parents of your teen's friends are unaware of their child's drug or alcohol use, or worse, condone it, that may make your child more likely to partake as well, the study found.

"Among friendship groups with 'good parents' there's a synergistic effect - if your parents are consistent and aware of whereabouts, and your friends' parents are also consistent and aware of their (children's) whereabouts, then you are less likely to use substances," study author Michael Cleveland, research assistant professor at Penn State University, said in a university news release. "But if you belong to a friendship group whose parents are inconsistent, and your parents are consistent, you're still more likely to use alcohol."

The study is published in the May issue of the Journal of Studies on Alcohol and... Researchers surveyed about 9,000 ninth-graders from rural school districts about their closest friends, their parents' discipline and if their parents knew who their friends were. After questioning the teens, the researchers identified nearly 900 different groups of friends, each made up of about 10 to 11 teenagers. One year later, the teens were surveyed again about their use of cigarettes and marijuana.

Teens whose parents were consistent in their discipline and generally knew what their children were up to were less likely to use drugs or alcohol. However, even if parents were consistent and aware of their teen's activities, some of that protection was erased if their friends' parents were more lenient or clueless.