Academic journal article Michigan Law Review

Digging into the Foundations of Evidence Law

Academic journal article Michigan Law Review

Digging into the Foundations of Evidence Law

Article excerpt

(ProQuest: ... denotes formulae omitted.)

DIGGING INTO THE FOUNDATIONS OF EVIDENCE LAW The Psychological Foundations of Evidence Law. By Michael J. Saks and Barbara A. Spellman. New York and London: New York University Press. 2016. Pp. xiv, 241. Cloth, $89; paper, $38.


Professors Michael Saks1 and Barbara Spellman2 have produced a gem of a book. A concise, cogent, and thoughtful introduction to the major rules of evidence, The Psychological Foundations of Evidence Law glitters in the light of ideas from social and cognitive psychology. PFEL, as I will abbreviate it, is an eminently accessible3 book that evidence professors should assign to their students; that psychologists seeking research questions about evidence law should consult;4 that litigators seeking to sharpen their persuasive powers should peruse; and that judges engaged in screening improperly prejudicial evidence from jurors should examine. In Saks and Spellman's words, the book

explores a number of important practices from evidence law about which psychology does, or could, have a lot to say to illuminate the underlying assumptions, and evaluates whether those assumptions are consistent with the psychological research or whether the law's goals for evidence doctrine could be achieved more successfully with a modified rule or a different rule or no rule at all. (p. 3)

This Review has three goals. Part I surveys PFEL's scope and provides examples of several of its conclusions. Part II focuses on one psychological (or logical) model that the book presents for understanding two fundamental concepts in evidence: relevance and probative value. It digs into the foundations of these concepts more deeply to expose a slightly different conception of the probative value, or, more metaphorically, the weight of evidence.


At a granular level, the sheer number of rules of evidence is vast,5 but PFEL surveys the major federal rules with emphasis on probative value, counterweights to relevant evidence, character evidence, competency of witnesses, privileges, impeachment, hearsay, limited admissibility,6 and expert and scientific evidence.7 Throughout these areas, PFEL maintains that psychology can improve on rulemakers' "assumptions, impressions, anecdotes, and reasoning about human behavior" in two ways (p. 16)-by conducting controlled experiments (simulations with mock jurors and "similar studies to take place in the setting of actual trials")8 and by "borrow[ing] from the findings of more basic empirical research, or from theoretical knowledge about human perception, memory, and information processing" (p. 17). In particular, PFEL brings to bear findings about mental contamination ("how prior knowledge can bias future judgments in an unwanted manner"),9 dual systems reasoning (System 1's fast and frugal heuristics10 versus System 2's "slower, conscious, and reflective" processing) (p. 20), information integration theory ("how people combine bits of information into a final judgment") (p. 43), motivated reasoning (p. 208), contextual bias (p. 26), attribution theory (p. 79), "weapons of influence" (pp. 40-41), and "diffusion of responsibility" (p. 216). It also includes specific studies on such topics as the impact of gruesome pictures (pp. 64-65), observer or expectancy effects in forensic science,11 lie detection (pp. 122-28), decision aids for expert evidence (pp. 226-27), and framing effects in the presentation of statistical evidence (pp. 221-22).

On the basis of such theory and findings, Saks and Spellman give the modern trial process high marks in some respects. As they see it, "[t]he rules came into being to rein in the inevitable excesses of lawyers in an adversarial system" (p. 11). That is, Saks and Spellman embrace the theory of several legal historians that "limits had to be placed on what . . . lawyers would be permitted to do" (p. 11) in an adversarial system as opposed to an inquisitorial one, in which these one-sided lawyers played a more ancillary role. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed


An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.