GAMBLER'S BIAS
It's called a fallacy, but it's more a glitch in our thinking. We tend to put a tremendous amount of weight on previous events, believing that they'll somehow influence future outcomes. The classic example is coin-tossing. After flipping heads, say, five consecutive times, our inclination is to predict an increase in likelihood that the next coin toss will be tails — that the odds must certainly be in the favor of heads. But in reality, the odds are still 50/50. As statisticians say, the outcomes in different tosses are statistically independent and the probability of any outcome is still 50%.
Relatedly, there's also the positive expectation bias — which often fuels gambling addictions. It's the sense that our luck has to eventually change and that good fortune is on the way. It also contribues to the "hot hand" misconception. Similarly, it's the same feeling we get when we start a new relationship that leads us to believe it will be better than the last one.
POST-PURCHASE RATIONALIZATION
Remember that time you bought something totally unnecessary, faulty, or overly expense, and then you rationalized the purchase to such an extent that you convinced yourself it was a great idea all along? Yeah, that's post-purchase rationalization in action — a kind of built-in mechanism that makes us feel better after we make crappy decisions, especially at the cash register. Also known as Buyer's Stockholm Syndrome, it's a way of subconsciously justifying our purchases — especially expensive ones. Social psychologists say it stems from the principle of commitment, our psychological desire to stay consistent and avoid a state of cognitive dissonance.
NEGLECTING RESPONSIBILITY