Inividual Irrationality Cialdini's book Influence: The Psychology of Persuasion listed six human behavioral tendencies that defies rationality.

The six tendencies and my interpretations are:

Reciprocation - We want to give something back when we received a favor. Investment implication: We tend to loose up our discipline after a big gain.

Commitment and Consistency - We hate to change our decision or believe once we are committed, especially when we make the commitment public. Investment implication: We tend to commit to a winning stock and refuse to change our commitment.

Social Validation - We tend to follow what the majority of the crowd do. Investment implication: We want to follow tips, buzz, hot picks by professionals, etc.

Liking - We tend to say Yes to the people we like. Investment implication: We tend to buy the stock we like without doing adequate research.

Authority - We tend to follow orders from higher authority even if the order is obviously wrong and ridiculous. Investment implication: We tend to follow analysts' recommendations.

Scarcity - We find scarce things more attractive. Investment implication: We tend to believe scarce information.  ¶ 11:29 AM