According to Raph Koster in his book A Theory of Fun for Game Design, one of the four major source of enjoyment can be found in social interactions (Koster 92). These interpersonal interactions include:
- Schadenfreude -- pleasure from watching a rival fail
- Fiero -- expression of triumph after completing a significant task
- Naches -- enjoyment from watching someone you mentor succeed
- Kvell -- the emotion that comes from bragging about a pupil's accomplishment
- Grooming behaviors -- signals of intimacy
- Feeding others -- (also giving gifts)
Some of these, particularly fiero, are discussed by Jane McGonigal in her TED Talk "Gaming can Change the World."