In this chapter, we examine people's ability to envision conditions that would falsify the theories they hold, that is, their ability to generate a counterargument to the theory and supporting evidence that comprise the primary argument. Some subjects do generate successful counterarguments in response to the interviewer's request (“Suppose now that someone disagreed with your view that this is the cause. What might they say to show that you were wrong?”). Others attempt to do so unsuccessfully or decline to make the attempt.

Still others generate only an alternative theory in response to the request for a counterargument. These subjects conceive of another theory that might serve as an alternative to their own, but not any evidence that would challenge the correctness of their own theory. In such cases, the interviewer probes further in an effort to elicit a genuine counterargument (“What evidence might this person give to try to show that you were wrong?”). (See appendix 1 for full sequence of probes.) In this chapter, we look at examples of each of these outcomes and then examine quantitative data regarding their prevalence.

SUCCESSFUL COUNTERARGUMENTS

Counterarguments involving causal sufficiency and/or necessity

The most cogent arguments against the correctness of a causal theory are those demonstrating that the alleged causal factor is not sufficient to produce the outcome and/or is not necessary to produce the outcome. Such demonstrations consist of evidence of one or both of two possible forms of noncovariation between the alleged causal factor (the antecedent) and the outcome.