Evaluating Psychologists as Expert Witnesses
Evaluating Psychologists as Expert Witnesses
In child-abuse cases, both sides often call psychologists as expert
witnesses, but many peopleincluding judgesare confused about what,
exactly, a “psychologist” is. They generally assume that all psychologists
do therapy; but many psychologists are not clinical practitioners of any
kindrather, they are scientists who study human behavior. It is important
to understand the difference. Many “psychotherapists” have no scientific
training, do not keep up with research, and are not even aware of basic
principles of the scientific method. Thus it is up to defense lawyers to
keep junk science and unreliable testimony away from the jury. In what
follows, NCRJ Advisor Dr. Carol Tavris first explains the kinds of
psychotherapists and the kinds of psychological scientists. Next, she
explains how to assess the scientific validity of expert testimony.
The Scientist-Practitioner Gap/Carol Tavris, Ph.D.
KINDS OF PSYCHOTHERAPISTS
- PSYCHOTHERAPIST: Anyone who does “psychotherapy”; the word is unregulated; no degree necessary.
- CLINICAL PSYCHOLOGIST: Has a Ph.D., Ed.D., or Psy.D. (advanced graduate work but usually no research dissertation required). This degree used to guarantee that its recipient had been trained in the “scientist-practitioner” model and had learned scientific methods as well as clinical approaches. Increasingly, however, psychotherapists and clinical psychologists are trained in free-standing schools that are unconnected to university psychology departments and that do not emphasize research or the scientific method.
- PSYCHOANALYST: Has specific training in psychoanalysis after advanced degree (usually, M.D. or Ph.D., but increasingly MSWs and others).
- PSYCHIATRIST: A medical doctor (M.D.) with a specialty in psychiatry. Most used to be trained as psychoanalysts; today, most have a biological view of personality and mental disorders and are entitled to prescribe medication. But few actually have much training or experience in scientific research and empirical psychology.
- LICENSED CLINICAL SOCIAL WORKER (LCSW); MARRIAGE, FAMILY, AND CHILD COUNSELOR (MFCC): Licensing requirements vary; usually at least a Master’s degree in psychology or social work.
- A ZILLION OTHERS, usually with no particular credentials or training other than a weekend course or “continuing education” workshop: play therapists, sand therapists, art therapists, hypnotherapists, heart-centered therapists, crisis counselors, “rebirthing” therapists . . .
KINDS OF PSYCHOLOGICAL SCIENTISTS
Academic psychologists do research, pure or applied, from various perspectives, including:
- Social: study people’s behavior in social and cultural context
- Cognitive: study thinking, decision making, mental biases, etc.
- Experimental: conduct laboratory studies of learning, motivation, emotion, physiology, etc.
- Biological: study human and animal physiology, genetics, temperament, etc.
- Cultural: study the influence of culture on behavior and personality
- Developmental: study physiological, social, and psychological changes across the life span
- Industrial/organizational: study human behavior and motivation in the workplace
- Psychometric: design and evaluate tests of mental abilities, aptitudes, and personality.
ASSESSING EXPERT TESTIMONY: QUESTIONS TO ASK
The differences in the goals, attitudes, and methods typically used by psychological scientists and psychotherapists are apparent in the kinds of testimony that each side is likely to offer in the courtroom. Following are ten critical questions to consider in determining whether a clinical expert—from a psychotherapist with no particular degree to a psychiatrist with dozens of publications—is relying on pseudoscience ane/or personal intuition rather than on scientific evidence in his or her testimony.
- What is the source of the expert’s knowledge—not only credentials, but also training and background? Has the expert a solid grounding in scientific methods, or has the expert acquired “expertise” through a weekend credentialing course or a diploma mill?
- Does the expert have a conflict of interest—e.g., making forensic diagnosis and treating the client? Did the expert use a forensic lab that was independent of the prosecution and police?
- Has the expert submitted his or her ideas to disconfirmation—e.g., to the possibility that a child was not abused, that a suspect is not guilty?
- Is the expert’s theory or diagnosis nonfalsifiable? That is, does he or she squeeze all evidence into being “support” for his or her conclusions?
- Is the primary source of the expert’s knowledge “years of clinical experience” and “clinical insight”?
- Is the expert’s assessment of a defendant based on unreliable projective tests (such as the Rorschach Inkblot Test or children’s play with anatomically detailed dolls) or on empirical methods—including the use of control groups and objective, validated tests?
- Are the expert’s published sources of support for his or her claims case studies, anecdotes, advocacy newsletters, non-peer-reviewed book chapters, convention papers and the like, or are they publications in peer-reviewed, scientifically reputable journals?
- Is the expert aware of how the normal processes of suggestion and influence in therapy, hypnosis, interrogation, or even normal interviewing can create false or tainted memories and false confessions?
- Does the expert offer diagnoses that are trendy but have little scientific support, such as Munchausen Syndrome by Proxy, Parental Alienation Syndrome, etc.?
- Does the expert speak in absolutes (e.g., “Children never lie”; “I know for sure…”)?