Evidence, procedure, and the upside of cognitive error.

• Author: Sanchirico, Chris William

INTRODUCTION I. THE TEST OF TESTIMONY A. The Correlation Between Knowledge and Interest B. The Necessity and Nature of the Test 1. The oath 2. The ordeal 3. Demeanor 4. The polygraph 5. Perjury and obstruction C. Testing Semantic Content D. General Evidence for Consistency and Detail II. PREPARING FOR TESTIMONY: WITNESS COACHING A. Comparison of Preparatory Tasks 1. Story construction 2. Contingent thinking 3. Memorization B. Additional Legal Applications 1. Use of writings in preparing testimony 2. Prior consistent and inconsistent statements 3. Asymmetric treatment of consistent and inconsistent statements 4. Witness exclusion C. Summary III. PERFORMING TESTIMONY: LIVE TESTIMONY AND CROSS-EXAMINATION A. Unanticipated Questions 1. The law of surprise B. Closed-Loop Control of Questioning 1. Implications for discovery C. Fatigue 1. Implications for discovery IV. THE CONTEST OF TESTIMONY A. Witness Versus Herself B. Witness Versus Questioner 1. The battle over consistency 2. Anticipation and closed-loop questioning 3. Cognitive artifacts 4. Fatigue and tag-team questioning 5. The sincere witness's strategy C. Factfinder Versus Witness Versus Questioner 1. Accommodation from attorneys 2. Accommodation from the judge 3. Cognitive artifacts V. REAL EVIDENCE A. The Creation of Cognitive Artifacts 1. Two case studies 2. The special efficacy of cognitive artifact evidence B. Control and Destruction of Real Evidence 1. Cognitive artifact evidence 2. Other real evidence CONCLUSION INTRODUCTION

As an information processor, (1) the human mind falls far short of its own ideal. Working memory--where intermediate information is stored in multistep thinking (2)--holds only about seven items, (3) and only for several seconds. (4) Longer-term memories can be purposefully acquired, but only with substantial effort and attention. (5) Even when successfully acquired, long-term memories cannot always be retrieved on demand. (6) Indeed, focusing the attention required for managing long-term memory--as well as for many other cognitive tasks--can itself be a challenge. (7) And just to make matters worse, the mind's limited capacity further constricts as it quickly grows fatigued. (8)

When legal scholars make reference to the limitations of human cognition, it is usually in connection with bad news about the legal system. Nowhere is this more clearly the case than in applications of cognitive psychology to evidentiary procedure. (9) A vast literature stretching back several decades is almost uniform in its grim prognosis for factfinding. (10) Eyewitnesses, we are told, see little, remember less, and often believe they remember what they never saw. (11) Witnesses' indications of confidence in the accuracy of their perceptions bear little relationship to actual accuracy. (12) Juries and judges nonetheless place substantial weight on witnesses' expressions of certainty and doubt. (13) Indeed, factfinders are purportedly prone to a full catalog of cognitive illusions and biases, symptoms of their general mental deficiency. (14) "Hindsight bias," (15) for example, causes them to believe that accidents that happened to occur were bound to happen and, thus, that sufficiently cautious defendants were negligent. (16) The "representativeness heuristic" (17) induces them to place too much weight on whether the evidence matches their mental picture of, for example, negligent behavior, and too little weight on the base frequency of such behavior in the population. (18)

Though somewhat less pronounced, a similar pessimism informs applications of cognitive psychology to substantive-law fields. To be sure, many of the applications in this more recent research program are put forward primarily as challenges to the methodology of law and economics, with its "working assumption" that individuals are perfectly rational. (19) But many also speak directly to the detrimental effect of cognitive limits in the substantive-law arena. Thus, we read that consumer choice with regard to dangerous products may not be the rational expression of economic preference, but rather the outcome of systematic mistakes in judging risk which have, in turn, been manipulated by producers. (20) And even in the absence of transaction costs (as conventionally defined), parties to a nuisance dispute may not bargain around an ill-informed verdict, as the Coase theorem (21) would optimistically predict. (22)

Taken individually, many elements of the literature applying cognitive psychology to substantive and procedural law make valuable contributions, not just to our understanding of the legal system, but also to its practical design. (23) Viewed as a whole, however, the literature offers a woefully unbalanced account of what human imperfection means for law. Ironically, nowhere is the account more askew than with regard to evidentiary process. For when it comes to how the legal system itself processes information, the limits of the human mind are as much an instrument as an impediment. (24)

Elucidating the instrumental value of cognitive imperfection to evidentiary process is the primary object of this Article. (25) Secondarily, the Article sets out to show how the law of evidentiary procedure tilts the playing field of litigation in a manner that mitigates the cognitive failings of certain actors while exacerbating the failings of others. En route to both objectives, the Article provides a novel perspective on several critical, though underanalyzed, topics in the law of evidence and procedure. More generally, in exploring how cognitive limits bear on the pervasive issue of legal information processing, the Article casts new light on the significance of cognitive limits for law as a whole.

The argument for the existence of an upside to cognitive deficiency begins with a simple, but apparently elusive, point: the normative status of mental limitations depends on the object to which the mind is directed. This Article stands apart in its approach to cognitive error because it focuses on a set of mental objectives that to date have been largely ignored in applications of cognitive psychology to law, both substantive and procedural.

Where cognitive psychology has been applied to substantive legal rules, these rules are most often considered in a form that is disembodied from the problem of how the law gathers the information required for implementation and enforcement. In this artificial realm, we may stipulate, the fact that individuals have limited cognitive capacity is usually a detriment to social welfare. When, for example, the individual's mental objective is to identify remote contractual contingencies or minimize accident avoidance costs, the greater her capacity to process information, the better for society.

Applications of cognitive psychology to evidentiary process, on the other hand, have addressed only certain issues in that field. Near exclusive attention has been paid to the perception and memory of the truly disinterested witness and the rationality of the truly impartial trier of fact. Again, we may stipulate that when the mind under study belongs to one of these beneficent actors, the greater its cognitive capacity, the better for social welfare.

But surely the dramatis personae of evidentiary process consists of more than just disinterested witnesses and impartial factfinders. After all, what about the "bad actor" (26) of evidentiary process--the one who cogitates about evasion, who ruminates on deceit, who deliberates about how to break the law without a trace; the one who lies under oath, (27) alters phone logs, (28) shreds key documents? (29) We well understand the archetype of the evil genius. (30) Then, too, we should understand that when the individual puts her mind to fabricating an airtight alibi, covering up a paper trail, or obfuscating clear of her opponent's burden of proof, her cognitive limitations are a boon for system function. (31)

The perfect mind, after all, effortlessly constructs the perfect lie, anticipating much of cross-examination. It easily comprehends the constellation of evidence that is likely to be available to the other side and weaves its lie through these fixed objects with agility. Even when a question is unanticipated, the perfect mind spontaneously and consistently extrapolates in a manner consistent with both its own prior statements and other available evidence.

Needing no notes to keep straight the details of its illicit plan, the perfect mind leaves no evidentiary trail of documents, records, and other "cognitive artifacts." (32) Even when the perfect mind must resort to making records, it remembers if and where the records are stored, it keeps straight whether and where any copies were made, and it comprehensively erases these evidentiary traces of its activities--without then leaving additional traces of the erasure.

The limited mind, in contrast, has difficulty thinking more than several steps ahead in anticipating the give and take of cross-examination, it pauses to answer the questions it has failed to foresee as it attempts to calculate what kind of answer will be both consistent with prior testimony and also unlikely to lead to yet another difficult question. The limited mind quickly fatigues, whereby its attention and working memory become woefully impaired. Late in the day, deep into the deposition, it cannot remember the details of the answer it gave to a sneakily similar question five hours earlier. Rehearsal is an intense, time-consuming, and doubtful solution. The limited mind, unable to fully anticipate the questions it will face, is equally unable to target preparatory effort. What it ultimately decides to rehearse, it is slow to learn and quick to forget.

In the process of perpetrating its crime, tort, or breach, the limited mind takes copious notes to help it pay attention, to help it comprehend, to help it remember what to do next and what to say to whom. It forgets that these notes exist. It...