Perception and Persuasion in Legal Argumentation: Using Informal Fallacies and Cognitive Biases to Win the War of Words

CONTENTSI. INTRODUCTION 320II. KEY CONCEPTS AND HISTORICAL BACKGROUND 325A. Perception and Persuasion 3251. Perception 3252. Persuasion 3273. The interaction between perception and persuasion 330B. Informal Fallacies and Cognitive Biases 331J. Informal fallacies 3312. Cognitive biases 3343. The connection between informal fallacies and cognitive biases 336C. Background and Context: Sophists, Philosophers, and Lawyers 337III. EYEWITNESS TESTIMONY, WRONGFUL CONVICTION, AND THE COURTS 341A. Cognitive Psychologists and Legal Scholars on Eyewitness Testimony 341B. Courts' Limited Role in Excluding Unreliable Testimony 343J. Excluding opinion that lach a rational connection to actual perception 3432. Excluding unreliable identifications due to suggestive circumstances 344IV. CONNECTING THE LINKS BETWEEN SPECIFIC INFORMAL FALLACIES AND SPECIFIC COGNITIVE BIASES 349A. Fallacy of Irrelevant Thesis and Bounded Awareness 349B. Fallacy of Exclusion and Confirmation Bias 352C. Fallacy of Style over Substance and the Framing Effect 354D. Fallacy of Emotive or Loaded Language and Suggestibility 355E. Poisoning the Well, the Straw Man, and Cognitive Dissonance 357V. CONCLUSION 360I. INTRODUCTIONWhen zealously advocating a client's position, the lawyer's ultimate goal is winning. To win, however, the lawyer must convince a judge or jury to accept the lawyer's (and reject opposing counsel's) position. The best type of advocate accomplishes this goal using various rhetorical techniques, attempting to manage other people's perceptions of such things as the facts, the lawyer's own theory of the case, the credibility of eyewitness testimony, the weaknesses of opposing counsel's claims, and the praiseworthiness of the lawyer's own client. By design, we have an adversary system. Roberto Aron and his colleagues characterize litigation quite deftly.Litigation is not a philosophical discussion. Trial advocacy is always controversial. A trial is a judicial contest between lawyers where a given situation and set of facts are interpreted in various ways by the different parties' lawyers, each counsel trying to persuade the judge or jury that justice is on the side of the client for whom counsel is arguing.1But how does the lawyer successfully convince the fact finder that the lawyer's (and not opposing counsel's) position is aligned with justice? Success inevitably boils down to persuasive legal argumentation.2 This is because "the advocate's [only] weapons in the courtroom battle are methods, tactics, and strategies, all of which have in common the ultimate goal of persuasion."3 When lawyers do battle in the courtroom, whichever warrior wages war while wisely wielding wittier words without waning will win. Thus, if the lawyer's ultimate goal is winning, the lawyer must master the art of persuasion. For the art of persuasion4 is intimately connected with the psyetiological process of perception. And perception is what convinces people whether to accept or reject the lawyer's argument.In this Comment, I propose an account of legal argumentation that explains the relationship between mental processes that psychologists label cognitive biases5 and legal arguments that philosophers label informal fallacies.6 Cognitive biases are errors in our thinking and reasoning, which alter our perceptions. Informal fallacies are verbal or written arguments containing material flaws, which enhance their persuasiveness.7 I also describe the process of persuasion at play when the lawyer uses legal arguments that contain informal (material) fallacies. By using legal arguments that contain informal fallacies, the lawyer can play upon the listener's inherent cognitive biases to persuade the listener to see things the same way the lawyer does. When lawyers use these rhetorical techniques - whether before or during trial proceedings - they induce8 in most listeners erroneous perceptions that can, and often do, powerfully alter their listeners' beliefs. …