Our court system allows lawyers to examine witnesses using logically flawed questioning that distorts the truth.

Is Logic Optional? Lawyers' Persuasion Techniques
Do Not Always Comply with the Rules of Logic

Christine Alksnis, PhD
Edward Renner, PhD
Laura Park, PhD

            The adversarial model is the foundation of the legal system in Canada. Crown attorneys and Defence lawyers each question witnesses about various aspects of the alleged crime. Both lawyers are attempting to persuade the judge and/or jury to accept their version of the incident. But in our analysis of sexual assault cases in Canada, lawyers' methods do not always conform to the rules of logic.

            Arguments that are not logically sound can still be very compelling. For example, logically flawed arguments that are passionately presented may still effectively sway listeners' opinions.

            Criminal trials may occur months, sometimes years, after the alleged crime. Psychological research has shown that even for adults with normal memory process, small details become more difficult to recall accurately with the passage of time. Defence lawyers often attempt to discredit the victim by asking witnesses to report on small, often irrelevant details about the alleged crime.

            If the witness is unable to answer a highly detailed question, the Defence proceeds to argue that nothing of the witness' version of the events should be believed. Such a conclusion is logically flawed and offends common sense. Just because a person forgets a small detail, doesn't mean that they do not remember the crime or the identity of the perpetrator.

            The following is an example taken from an actual sexual assault case in Canada. The defence in this case asked the witness if the silver adjustable wrench on display in the courtroom was the actual wrench used to threaten her during a sexual assault, or simply a wrench that looked similar. The witness had testified that the accused had threatened her with an adjustable wrench, the investigating police officers found such a wrench in the accused's van, and the wrench that they found was now an exhibit.

            Nevertheless, the Defence argued that since the witness could not differentiate between various silver adjustable wrenches that there was reason to doubt the accuracy of her testimony about being assaulted.

            It does not logically follow that if a witness cannot recall the minute details of a weapon, that no weapon was present and no crime was committed. A woman being sexually assaulted is unlikely to be concerned with what brand or size of weapon the attacker is using to threaten her.

            When defence lawyers are permitted to ask logically flawed questions without being corrected by the Crown attorney or the judge, the legal system that society has put in place to achieve justice may actually contribute to an unjust outcome for the victim. When the judge and the Crown do not challenge illogical arguments, jury members may assume that the arguments are acceptable.

            Jury members are not warned that (1) known potent persuasion tactics will be used during the trial based on the psychology of social influence, and (2) that the goal of using these tactics is similar to that of advertising, not to uncover the truth. Psychological research has shown that messages are less persuasive when the audience is aware that specific known tactics of manipulation will be attempted.

            Crown attorneys and judges do not identify and reject logically flawed arguments. The role of the crown is to object to questions that are irrelevant or are based on faulty logic. However, analyses of court transcript data has revealed that the Crown tends to be very passive in sexual assault cases. In 55% of the cases, the Crown never objected, even once.

            Similarly, judges frequently fail to intervene when faulty arguments are presented. Although it is widely accepted that the judge should intervene when Defence lawyers make errors of commission, (e.g., badgering the witness or introducing material that is irrelevant to the case), the judge can also intervene when Crown attorneys make errors of omission (e.g., neglecting to protect the witness from illogical lines of questioning). Yet, the judge seldom interjects for any reason during the course of the trial.

            There are psychological factors at work in the courtroom that may prevent justice from being served. The use of illogical arguments during persuasion attempts is just one manifestation of this problem.

This article is based on a research paper by the authors entitled “The Standard of Social Justice as a Research Process” which appeared in Canadian Psychology, 1997, 38 (No. 2, May), 91-102, the professional journal of the Canadian Psychological Association. For more information on this research series see: www.napasa.org.

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