This document discusses 5 concepts from social psychology:
1. Discrimination and stereotyping, such as negative views of people with tattoos.
2. The halo effect, where one positive trait causes us to positively judge other unknown traits.
3. Optimism bias and counterfactual thinking, like being overly optimistic about academic results.
4. Self-fulfilling prophecies, where expectations of others can influence their actual performance.
5. Social loafing in groups, where people put in less effort due to diffusion of responsibility.