When it comes to watching your back, hone in on narcissism and anger.
Not surprisingly, not everyone is inclined to vengeance and some are much more inclined than others as research shows; additionally, certain emotions such as anger are much likely to up the possibility of revenge as well. People who set great store by their reputations, for example, are more likely to seek revenge if they feel they and their honor have been unfairly impugned. But the clear winner on the vengeful scale is the person high in narcissistic traits. Up next? The one high in neuroticism.