From emulating celebrities we admire, to buying that "cool" pair of jeans that the "popular" girls all have, we all copy from the world around us sometimes. And when it comes to relationships, copying can be one of the main ways we compliment or show admiration for our friends. But that doesn't mean it's always welcome!

Believe it or not, copying friends is actually a normal part of our social development, and it happens both consciously and unconsciously. For example, if you find yourself in an awkward situation, you may look to your more experienced friends for information on what would be considered appropriate behavior. If a friend has qualities that you admire, you may copy her or him in the hopes of sharing those qualities. Finally, if you copy what your friends wear, think, or say, it may help you feel like you're fitting in.

"I think most people copy because they like something that their close friend has or does, which is OK," says Jessica, 19. "What's not OK is when friends copy because they don't have their own ideas or opinions."

Dr. Benjamin Karney, associate professor of social psychology at the University of Florida, explains that people often define themselves in part through the social groups to which they belong. "When a group is doing well, people like to affiliate themselves with that group, and will dress in ways that identify themselves as members, like in the movie Mean Girls," he says. "We tend not to copy people unless we admire them and want to be like them. The problem is that it is also nice to be unique."

Can't Get You Out of My Head

The tension between fitting in and being unique is pretty central to modern social life, and different people resolve it in different ways. When someone copies you, they may threaten your uniqueness, and that can be extremely irritating. That's why it's important to keep the lines of communication open with your friends. If they are over-copying you and it's driving you nuts, it's a good idea to express your feelings about it early on.

"If I do something that my friend likes, it's no biggie if they copy me, but if they start to do everything I do, it goes too far," adds Jessica. "I value individuality in a friendship. I'm with myself all of the time. Why would I spend more time with someone who is exactly like me?"

Occasionally, copying can go from simple flattery to more dangerous territory. If your friend starts to smother you, "steal" your life,, or behaves in a way that makes you feel threatened or intimidated, it's time to talk to a parent or teacher you can trust. In a situation like this, says Karney, something is probably wrong in the relationship. "Everything needs to get out into the open if the relationship is to continue," he says. "Or it may be a sign that the relationship should end for the health and safety of everyone involved."

Just Like Me

We can discover a lot from watching and copying others. In fact, it's one of the main ways we learn. But maintaining a sense of individuality is also key. The trick is keeping everything in balance. Don't be afraid to express your uniqueness — it's what makes you you.

"Copying can be very flattering at times, but it has its limits," says Dave, 14. "One should never feel the need to try to completely become the person they look up to. Be sure to keep yourself in the mix!"