The "Anna Karenina Principle" That Explains How Optimists Differ from Pessimists

The first line of Leo Tolstoy's famous novel Anna Karenina offers this observation:

“All happy families are alike; each unhappy family is unhappy in its own way.”

Based on a recent research study, there may be some science that actually proves his point. Neuroscientists studying key brain patterns among people who imagined positive events with a feeling of optimism versus those who did so with pessimism found that the optimists brain patterns were largely similar. For pessimists, those same patterns varied widely. The aim of the study was to try and ​understand what distinguishes optimistic thinking from pessimism​.

Given the conclusions of prior studies showing that optimists have larger social networks, higher acceptance from peers and ​generally show better physical, mental and social health​ ... this is an important psychological difference to study. There is also evidence to suggest that optimistic versus pessimistic thinking may evolve with age and that extreme optimism may also be unwise because it can prevent someone from adequately preparing for the future.