They reviewed 42 scientific studies of Facebook users and have discovered the following:
- Healthy people enjoy using Facebook because it improves self-esteem (our shield against feeling like outcasts). Women and members of ethnic minorities use it more than men and Caucasians.
- Healthy people don't idealize themselves on Facebook, with one big exception: they present themselves as more emotionally stable than, in fact, they are.
- Narcissists especially enjoy using Facebook, and spend an hour every day in front of the screen. And they love to upload photos, often enhanced with Photoshop.
- Highly neurotic people share more on Facebook than healthy people. They prefer written posts over photos.
- Extraverts have more Facebook friends and are more likely to become Facebook addicts.
- Introverts substitute Facebook use for real-world social interaction. And shy people spend more time on Facebook than people who aren't shy.
- Good-looking Facebook users are more attractive to other users than plain-looking ones; so are users with good-looking friends.
- Facebook users with only 100 friends are unattractive to other users; so are users with 300 friends.