As Second Life and other massive multiplayer online role playing games become increasingly popular, scientists at Stanford University have begun researching how someone's "avatar," or digital persona, changes how they behave in the real world. The researchers hypothesized that specific attributes of an avatar like facial attractiveness and height might influence the real world creator's actions. The team tested this hypothesis in an immersive virtual reality environment, where subjects wore virtual reality goggles, first saw their virtual self in a mirror and then interacted with another subject in a controlled environment.

Immediately, "people placed in attractive avatars become more sociable," said Nick Yee, a graduate student who conducted the research, dubbed "The Proteus Effect," with a paper currently awaiting publication. "People conform to the stereotype of their avatar."

In Second Life users can customize their avatars with 150 detailed features, such as the width of their nose and the length of their arms. Users can also buy clothing and accessories. The Proteus Effect implies that having an attractive avatar in such virtual worlds boosts the confidence and social skills of the user behind it when they leave the computer and go about their regular lives. Yee notes that most users of MMOs create avatars that are more attractive, powerful, youthful and athletic than their real world counterpart.

"Who we choose to be in turn shapes how we behave," Yee writes in the draft paper. "While avatars are usually construed as something of our own choosing – a one-way process – the fact is that our avatars come to change who we are."