Imaginary friens, also known as "imaginary companions", are pretend characters often created by children. Imaginary friends often function as tutelaries (or perform a tutelary function) when they are engaged by the child in play activity. Imaginary friends may exist for the child into adolescence and sometimes adulthood. Imaginary friends often have elaborate personalities and behaviors. Although they may seem very real to their creators, studies have shown that children understand that their imaginary friends are not real.