Jury Inferential Errors

Faced with the problems of insufficient evidence, of conflicting evidence, and of evidence relayed through the flawed perceptual, retentive, and narrative abilities of witnesses, a jury is forced to draw inferences in its attempt to ascertain the truth. By applying the same cognitive tools they have developed and used over a lifetime, tools may cause jurors to commit inferential errors that distort rather than reveal the truth.

Although juries can make a variety of inferential errors, most of these mistakes in judgment involve the drawing of an unwarranted conclusion from the evidence, that is, deciding that the evidence proves something that, in reality, it does not prove. For example, evidence that the defendant in a criminal prosecution has a a jury that its members would draw totally unwarranted conclusions or even ignore the evidence entirely.

Recent empirical research in cognitive psychology suggests that people tend to commit inferential errors like these under certain predictable circumstances. By examining the available information, the situation, and the type of decision being made, cognitive psychologists can describe the kinds of inferential errors a person or group is likely to make. These evidence on the reliability of the jury’s inferential processes in certain situations.

The notion that juries can commit inferential errors that jeopardize the accuracy of the fact-finding process is not unknown to the courts. In fact, one of a presiding judge’s duties is to minimize jury inferential error through explanation and clarification. Nonetheless, most judges now employ only a limited and primitive concept of and conclusions of psychologists in favor of notions about human cognition held by lawyers.