Should we trust psychologists and psychiatrists, especially as expert witnesses in court cases?

This is an important question because, depending on their opinions, a person can inherit vast sums of money, lose custody of a child, be tried for murder or shut away for life in gaol or an asylum.

Two American psychologists, Jay Ziskin and David Faust, have looked at the performance of their own profession with a scientific eye and think they have good reason to question the accuracy of their colleagues’ opinions in courts. They point to several famous experiments.

In one study, several psychologists examined the same group of mental patients. The experts disagreed on the patients’ diagnoses, motivations or conflicts, and their conscious and unconscious feelings more often than they agreed on these things.

In other experiments, professional psychologists did no better than office secretaries in recognizing people with damaged brains, and few clinicians could distinguish between people with real brain damage and those only pretending. More studies showed that children feigning brain damage fooled most practitioners and professional psychologists did no better than high school students in predicting violent behaviour.

Several studies showed that psychiatric judgment did not improve with wide experience or special qualifications. Highly qualified old psychiatrists were no better than novices in spotting the presence, location or cause of brain damage.

Drs Faust and Ziskin think that many of these experts are ill fitted to work on criminal courts for two reasons. In their day-to-day work, psychologists and psychiatrists have an ingrained tendency to help and sympathise with their patients. But in the unfamiliar arena of the court they must do something quite different — uncover truth whatever the implications are for the accused, so their judgment is often clouded.

Another reason for their failure is because their disciplines are not yet true sciences. Human thought and behaviour still resist objective, direct, reliable observation and measurement, so clinicians can make few accurate predictions. In the place of science, psychology has only loosely bound conjectures — dozens of fash-ionable personality theories and hundreds of ever-changing approaches to psychotherapy. New theory may not be better, only a fresh attempt to resolve a recalcitrant problem.

Check this out in Jay Ziskin and David Faust’s three-volume Coping with Psychiatric and Psychological Testimony. Fifth Edition 1997. Nothing here about New Zealand psychologists and psychiatrists who are, of course, a cut or two above their American counterparts.

Originally published in the Dominion Post, January 26, 2003. A book of Bob Brockie’s collected columns is being released August 2003.

Recommended Posts