Chances are, you've either heard of or joined a Facebook group over the years. It's a great way for people to connect with friends, loved ones, neighbors or people who you hate with a passion but want to stalk so you can see that you're doing better than them.
There are "swap" groups across the country that let people buy and sell their junk. There are "living" groups that help people find businesses or find out what's going on around town.
In the 1990s, a psychologist named Martin Seligman led the positive psychology movement, which placed the study of human happiness squarely at the center of psychology research and theory. It continued a trend that began in the 1960s with humanistic and existential psychology, which emphasized the importance of reaching one's innate potential and creating meaning in one's life, respectively.
