REASONING FROM FALSE PREMISES - THE ROLE OF SOUNDNESS IN MAKING LOGICAL DEDUCTIONS

A believable conclusion is usually judged more acceptable than an unbe lievable one, all other things being equal. However, there has been li ttle empirical work to address how the believability of the premises a ffects the acceptability of an argument. In the present experiment, pa rticipants solved problems having either believable, unbelievable, or neutral premises, and having either believable or unbelievable conclus ions. People were more likely to accept a conclusion when it was suppo rted by believable premises than when it was supported by either unbel ievable or neutral premises; this effect was true of both valid and in valid arguments. The fact that premise believability did not interact with logical validity suggested that premise believability acts indepe ndently of logical analysis. The results suggest a ''filtering'' mecha nism, which operates after logical analysis has occurred, and which re jects conclusions that are unbelievable, or that are derived from unbe lievable premises.