Judgment and Reasoning: An Overview
There are both parallels and contrasts between judgment and reasoning. In both domains, we find uneven performance—sometimes people are capable of wonderfully high-quality thinking, and sometimes they make outrageous errors in their judging or reasoning. We also find, in both judgment and reasoning, that various factors or cues within a problem can trigger better quality thinking (System 2)—so that the way someone thinks depends heav-ily on what they’re thinking about. Thus, when thinking about a Sunday football game, peo-ple are alert to the role of chance and wary of drawing conclusions from a single game. The same people, in thinking about a job interview, might not realize the sample of information is small and so might overinterpret the evidence. Likewise, people’s performance in the selection task is fine if the problem contains cues suggesting a possibility of cheating or a need for permission; the same people perform miserably without these cues.
Judgment and reasoning differ, though, in how they proceed in the absence of these triggers. In making judgments, we often rely on System 1 thinking—a set of strategies that generally lead us to sensible conclusions and that are quick and efficient. But there’s no obvious parallel to these strategies in many reasoning tasks—for example, when we’re trying to evaluate an if-then sentence (like the one in the selection task). This situation is reflected in the fact that people don’t make occasional errors with logic problems—instead, we’ve mentioned error rates of 80 and 90%! It’s fortunate, therefore, that our daily experience unfolds in a context in which the triggers we need, leading us into better quality reasoning, are often in place.
One last parallel between judgment and reasoning is important and quite encouraging: In both domains, training helps. We’ve mentioned that courses in statistics, and training in the interpretation of data, seem to improve people’s judgment—perhaps by making them more sensitive to the need to gather an ade-quate sample of evidence and by making them more cautious about samples that may be biased. Education also improves people’s ability to reason well—and, again, the education seems to help by making people more alert to cues that might trigger decent reasoning—cues that help people to think about issues (for example) of per-mission or obligation (Lehman & Nisbett, 1990). Thus, we can offer the optimistic conclusion that, with the appropriate training , people can learn to think more care-fully and accurately than they ordinarily do.