The fact that we are aware of our own beliefs, feelings, and desires does not automatically make us experts on where they come from. Introspection is therefore an unreliable guide to how the mind works, reflecting cultural truisms rather than providing infallible insights.
Our intuitive theories about how things are subtly shape our memories for what has been. Thus, we unknowingly reconstruct the past in terms of the present rather than simply remembering the past in its original form.
Although we are fairly adept at predicting how events will make us feel, we overestimate how long those feelings, especially when unpleasant, will last. One reason for this is that we possess a psychological immune system that, over time and without our knowledge, softens the impact of life's trials and tribulations.
Our group loyalties and preconceptions cause us to perceive events and other stimuli in a biased manner. One consequence of this is that partisans on both sides of an issue tend to overestimate bias in media reports.
People avoid risks when they stand to gain, but take risks when they stand to lose. Consequently, how a choice is framed, in terms of loss or gain, can influence how people choose, over and above the objective consequences of choosing one way or the other.
If you wish to change somebody's opinion, subtly induce them to act at odds with it while letting them think they did so of their own free will. This tactic works because people readily rationalize objectionable actions for which they feel responsible by adjusting their attitudes to match them.
When people voluntarily undergo an unpleasant experience to achieve something, they come to value that something more, not less. This helps explain why people become committed members of groups even when membership entails considerable initial sacrifice and offers scant subsequent reward.