Logic and Research Versus Intuition and Past Practice as Guides to Gathering and Evaluating Eyewitness Evidence

• Author: Stephen C. Want,John Turtle
• Date: 01 October 2008
• DOI: 10.1177/0093854808321879
• Published date: 01 October 2008
• Subject Matter: Articles

LOGIC AND RESEARCH VERSUS INTUITION

AND PAST PRACTICE AS GUIDES TO

GATHERING AND EVALUATING

EYEWITNESS EVIDENCE

JOHN TURTLE

STEPHEN C. WANT

Ryerson University

Psychologists have conducted extensive research and devoted substantial thought to the memory, cognition, decision-making,

logic, and human interaction components of eyewitness evidence. It is fortunate that much of that work has been formally

recognized by law enforcement and the legal community and used as the basis for procedure and policy changes with regard

to how eyewitness evidence is collected and evaluated. The authors discuss reasons that some segments of law enforcement,

the legal community, and the public resist these research findings (e.g.,by seeing psychology’s role as a way to discredit eye-

witness evidence or being committed to established procedures that have no empirical support). The authors also address gaps

between these common misconceptions and what the psychology research perspective has to offer, in an effort to gain even

more support for research- and logic-based recommendations concerning eyewitness evidence.

Keywords: eyewitness evidence; intuitive beliefs about memory; police investigation procedures

Like many issues in the psychology–law area, when it comes to eyewitness evidence,

researchers see an obvious opportunity to help solve a problem—in this case, to max-

imize the rate of accurate information and identification decisions while at the same time

minimizing the rate of mistakes. Psychology is especially well suited to this task, given its

interest in the psychological aspects of eyewitness evidence, such as attention (e.g., study-

ing an assailant’s face while being assaulted vs. learning only later that a bank customer

committed fraud by passing a bad check), perception (e.g., of color, distance, height,

speed), memory (e.g., length of retention interval, interference, source monitoring), deci-

sion making (e.g., determining the odds of a witness choosing a suspect by chance), inter-

personal communication (e.g., witness interviews), and attribution theory (e.g., a witness

wonders why she has been asked a particular question or shown a particular lineup).

So, to address the legal system’s “problem,” the box of tools familiar to psychology

researchers—stocked with things such as skepticism, empiricism, experimental design and

hypothesis testing, theory building, and practical application—is brought out of the truck and

carried to the job site where, combined with our existing knowledge, we expect to make some

progress on the homeowner’s predicament. In many cases, the tools and assistance are wel-

comed as helpful procedure and policy changes (e.g., National Institute of Justice, 1999; Wells,

2006; Wells, Malpass, Lindsay, Turtle, & Fulero, 2000), and field experiments are under way

to measure the effect of implementing these changes (see Steblay, 2008; Wells, 2008). In

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CRIMINAL JUSTICE AND BEHAVIOR, Vol. 35 No. 10,October 2008 1241-1256

DOI: 10.1177/0093854808321879

© 2008 International Association for Correctional and Forensic Psychology

AUTHORS’ NOTE: Please address correspondence to Dr. John Turtle, Department of Psychology, Ryerson

University, 350 Victoria Street, Toronto, ON M5B 2K3, Canada; e-mail: jturtle@psych.ryerson.ca.

other cases, however, a homeowner not familiar with the methods and goals of a research

perspective meets us on the driveway and tells us that the problem is already under control,

was working fine up until today, and that “it ain’t rocket science” to keep it up to their stan-

dards in the future. And besides, the homeowner continues, the floor plan in there is pretty

complicated, and they have heard that our own house is a bit of a mess, so maybe, they

politely suggest, we should go get that in order instead. In this article, we discuss some of

the reasons that a science-based approach to eyewitness evidence is sometimes difficult to

sell at first (or indeed even give away) to law enforcement and the legal community, with

the aim of gaining even more support for what we believe are beneficial strategies that have

already been adopted in several jurisdictions.

Lilienfeld and Landfield (2008) discuss much of the rationale for using science as the way

to figure out how the world works, but the problem remains that not everyone seems to always

agree with that rationale, and this difference of opinion can have serious consequences.

Although the scientific/scholarly community might take it for granted that their perspective is

best—personally, we feel it is obvious that science, logic, and research have proven them-

selves as the most productive routes to knowledge—it is literally a daily experience for psy-

chologists working in applied fields to talk with people who view these routes as just possible,

tenuous candidates among many alternatives, most of which boil down to some version of

interpreting their personal experiences based on their intuitive notions of how things work.

The clash between scientific perspectives and intuitive, personal notions of the way the world

works may indeed be particularly apparent to applied psychologists, as opposed to, say, the-

oretical physicists. It is obvious to most people that they cannot see atoms, or quasars, or dark

matter, so their lack of personal experience with those phenomena does not (usually) inter-

fere with a belief that they exist. But, they can definitely “see” that a psychic is sometimes

“correct” or that witnesses are sometimes extremely confident when they report an extraordi-

nary number of details about a particular memory. And, people are much more interested in

predicting their own future, and discerning true memories from false ones, than they are in

atomic structures, dead stars in remote galaxies, or the basic structure of the universe. So,

when it comes to thinking about everyday, human-scale problems, many people feel like they

are gathering evidence, testing a hypothesis, and arriving at a logical conclusion, based on an

nof 1 (themselves) in many cases.

It is ironic, and therefore often difficult to explain to others, that those with a science ori-

entation are usually more humble about their ability to divine how things work based on

personal experience. Our livelihood depends on knowing about confirmation bias, regres-

sion to the mean, probabilities of guessing correctly, unintended social influence, the

history of claims and refutations in a particular area, the burden of proof, and so on. So, it

is hard for us to make much of the fact that five witnesses who encountered an offender in

a pitch black room independently picked the guilty suspect from a lineup based on their

witnessing experience, except that something very wrong (or at least very unlikely) has

occurred. To some people, however, it might suggest that the world sometimes works in

mysterious ways—“You just never know, do you?” After all, the bad guy did get picked.

Therefore, any procedural recommendation based on the position that it is best to remove

human judgment from the equation and relinquish control to a general principle (which in

the case of the five witnesses who never saw the offender would likely lead to no identifi-

cations of him) is sometimes viewed as the antithesis of the best way to do the job.

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