If a teenager begins to adopt new behaviors and attitudes influenced by their friends, what is the likely underlying cause?

When a teenager starts to change their behaviors and attitudes because of their friends, it's usually because of peer group influence. This means that they are affected by the people they spend time with, as friends can strongly shape how someone thinks and acts. Teenagers often want to fit in and be accepted, so they may imitate their friends' interests or habits to feel more connected. For example, if a teen's friends enjoy a certain type of music or activity, the teenager might start liking those things too, even if they didn't before. This desire for acceptance and belonging is a natural part of growing up and can lead to both positive and negative changes.