Debiasing: Detection and Correction of Bias

WHAT TRIGGERS DELIBERATIVE DEBIASING EFFORTS?

Deliberative debiasing has two stages: deciding that bias has occurred and attempting to correct it. Naive theories can come into play at both stages. Because people do not have good access to their cognitive processes, they must rely on their theories when deciding whether a judgment is biased. Once this decision is made, people must again rely on their theories to inform them how to correct for the bias.

As noted by Martin and Stapel (1998), researchers have paid more attention to the second stage of the process (debiasing) than to the initial, bias-detection stage. In most of the research in this area, people are specifically instructed to avoid bias, which leaves open the question of when and how they invoke debiasing processes on their own (for exceptions, see Petty & Wegener, 1993; Stapel, Martin, & Schwarz, 1998).

How likely are people, in the absence of blatant warnings, to invoke a theory that their judgments are biased? Although this question is difficult to answer, our hunch is similar to Martin and Stapel’s (1998) that people’s default response is to assume that their judgments are uncontaminated. One source of evidence for this conclusion comes from studies showing that people are more willing to attribute bias to other people’s judgments than to their own (Kruger & Gilovich, 1999; Pronin, Puccio, & Ross, ch. 36, this volume; Wilson & Brekke, 1994; Wilson, Gilbert, & Wheatley, 1998).

The reason for people’s faith in their own judgments can be traced to both motivational and cognitive factors. On the motivational side, it can be disquieting to conclude that one’s own judgments are biased, and functional to overestimate the validity of these judgments (Taylor & Brown, 1988). On the cognitive side, the immediacy and inescapability of a phenomenal judgment probably contributes to its perceived validity. The phenomenal experience of one’s own judgment has a compellingness that is absent from the knowledge that someone else feels differently, which probably contributes to the greater faith in one’s own judgment.

Although the question of how often people detect bias and try to correct for it in everyday life is difficult to answer, we are not optimistic. If there were any group of people who would be particularly sensitive to mental contamination, one would think it would be research psychologists familiar with the extensive literature on biases in social cognition and the difficulty of avoiding these biases. We offer two anecdotes suggesting that psychologists are no more likely than others to take steps to avoid unwanted influences. The first is a colleague who said that when he grades his students’ papers and exams, he does so with full knowledge of the students’ identity and past performance, even though he is aware of studies showing that halo effects can color one’s impressions of papers and exams. “I don’t want to be biased by how much I like the students or how well they did on a previous test,” he said, “so I simply keep a close watch on myself to make sure this doesn’t happen.” Although this colleague is aware of research showing that people do not have direct access to how much they are biased by halo effects (Nisbett & Wilson, 1977a), he believes that he is an exception.

The second anecdote concerns the validity of the interview in predicting job performance of a job candidate. Despite evidence for the extremely low validity of the interview (e.g., Hunter & Hunter, 1984), the members of most departments of psychology are as confident in their impressions of a candidate after meeting him or her for half an hour as anyone else would be, and are as willing to let this impression override information known to be more valid (e.g., letters of recommendation, publication record). We confess that we often feel the same way. A strong impression of a person is so compelling and odorless, in Wilson and Brekke’s terms, that it is difficult to acknowledge that it might be tainted by unwanted influences, despite the fact that we are quite willing to see other people’s impressions as rather smelly.