Self-Serving Biases I

No one can make you feel small without your consent. ~ Eleanor Roosevelt

In statistics, the term bias is used for two different concepts. A biased sample is a statistical sample in which members of the statistical population are not equally likely to be chosen. A biased estimator is one that for some reason on average over- or underestimates the quantity that is being estimated.

While the term bias sounds pejorative, it is not necessarily used in that way in statistics. A biased sample can be difficult to analyze or may lead to inaccurate or wrong inference if the bias is ignored, but biased estimators may have desirable properties, such as small variance, depending on the situation.

A sample is biased if some members of the population are more likely to be chosen in the sample than others. A biased sample will generally give you a misestimate of the quantity being estimated. For example, if your sample contains members with a higher or lower value of the quantity being estimated, the outcome will be higher or lower than the true value.

A self-serving bias occurs when people are more likely to claim responsibility for successes than failures. It may also manifest itself as a tendency for people to evaluate ambiguous information in a way beneficial to their interests. Dale Miller and Michael Ross first suggested this attributional bias. Self-serving bias also results in a statistical bias resulting from people thinking that they perform better than average in areas important to their self esteem. For example a majority of drivers think they drive better than the average.

For instance, a student who gets a good grade on an exam might say, "I got an A because I am intelligent and I studied hard!" while a student who does poorly on an exam might say, "The teacher gave me an F because he does not like me!" When someone seeks out external causes for their poor performance, it may be labeled self-handicapping. Self-serving bias may simply be a form of wishful thinking.

Self-serving bias may result in bargaining impasse if each side interprets the facts of the dispute in their own favor. In this situation one or more of the parties may refuse to continue negotiating, believing the other side is either bluffing or refusing to accept a reasonable settlement and thus deserves to be ‘punished.’

There is a good deal of experimental evidence to support this hypothesis. In one experiment (described in Babcock & Lowenstein, 1997) which assigned participants to either the plaintiff or defendant in a hypothetical automotive accident tort case with a maximum potential damages payment of $100,000, the plaintiff’s prediction of the likely judicial award was on average $14,500 higher than the defendant’s. The plaintiff’s average nomination of a ‘fair’ figure was $17,700 higher than the defendant’s. When parties subsequently attempted to negotiate a settlement agreement, the discrepancy between the two sides' assessment of a fair compensation figure strongly correlated with whether or not parties reached an agreement within a set period of time. This experiment was conducted with real money with one real dollar being equal to $10,000 experimental dollars and if parties did not reach a negotiated agreement the case was decided by a third party and each side had to pay costly court and legal fees.

Group-serving bias is a similar bias on the group level.

Self-Terms
1. Self-Concept is an individual's system of images, perceptions and conceptions that can be attributed to him/herself as a person and the attitudes that person has about these attributes.
2. Self-Esteem is the positive or negative quality we attribute to ourselves. It is the evaluation we make about ourselves.
3. Self-Handicapping is the tendency to offer excuses prior to an effort (in case I don't do well, I have a built in excuse).