Contact with other adults
When teenagers are regularly in touch with adults other than their parents, such as family friends, parents of friends, older siblings, aunts and uncles, grandparents, and teachers, it has several positive effects on their ability and willingness to communicate with you.
Such exchanges with other adults reinforce their belief that adults have their best interest at heart and will listen to and respect them. Adults who have faith in them affirm their positive qualities, help them feel good about themselves, and encourage them to go on listening and learning. Also, they see that most adults - even those with different styles of parenting - share common concerns and attitudes so that if you've set a standard in something, the chances are the other adults will back you up; this is helpful and reassuring for your teenager.
While they may want to think that other adults will say that bedtimes are unnecessary, and that chocolate is a main food group, in reality, it's comforting to them to find that their parents sometimes do know best.