Envy arises when we compare ourselves to someone else and conclude they're better off. We've all been there. And while envy is a universal emotion, it's also a corrosive one. In a large longitudinal study of more than 18,000 adults, researchers found that higher levels of envy predicted poorer well-being years later. Put simply: The more envious we are, the worse we tend to feel over time.
Bandura (1977) showed that human beings tend to imitate those who appear to be powerful, or to be rewarded for their actions. When a "model" was observed by children to assault a "bobo doll" punching bag, the children generally tended to attack the bag with greater frequency and intensity, especially if the model was an adult (and hence relatively powerful by child standards), or was seen to be rewarded for the violent action. This "modeling" behavior was basic to the development of social learning theory.