When someone holds a one-sided point of view, we accuse him or her of being prejudiced, or having a bias. Human beings on an individual basis are inclined to interpret situations in biased ways, often based on their cultural norms and beliefs. But there is another kind of bias, called cognitive bias, that all humans share. Cognitive bias is our tendency to make systematic decisions in certain circumstances based on cognitive factors rather than evidence. Human beings exhibit particular inherent errors in thinking when we process information. These errors are the result of genetic predisposition that has arisen over time as humans have evolved; in fact, you can see many of the same biases that humans display in rats, birds, and monkeys. Researchers who study decision making theorize that somewhere in our evolutionary past, many of these biases helped us to survive. For example, the negativity bias causes us to give more weight to negative experiences than positive ones. In the dangerous environment in which our ancestors lived, avoiding negative outcomes likely meant life or death; being especially concerned with avoiding the bad made our ancestors more likely to survive. Other biases may be the result of our brains having limited processing power with which to analyze information, and therefore taking shortcuts—called heuristics—that sometimes lead us to irrational conclusions.
Behavioral economist Dan Ariely puts it thusly: "We usually think of ourselves as sitting the driver's seat, with ultimate control over the decisions we made and the direction our life takes; but, alas, this perception has more to do with our desires—with how we want to view ourselves—than with reality." Bias affects everything we do: from deciding how to handle our money, to relating to other people, to even how we form memories of the past. Though many of these biases were beneficial in the past, these days they sometimes lead us to make big mistakes. Loss aversion, the cognitive bias that makes us strongly prefer avoiding losses to acquiring gains, causes many people to make awful economic decisions. Marketing executives use this to their advantage: you'll sign up for a free trial of a service and then be loathe to cancel it, avoiding a loss. Though we can't eradicate bias—it's far too deeply wired for that—we can try to be aware of it. As we learn more about these biases and where they come from, humans become better equipped to understand why we do the things we do.Read more