Study finds ‘junk science’ used as evidence in courts

WASHINGTON — Courts are not properly screening out unreliable psychological and IQ tests, allowing junk science to be used as evidence, researchers have concluded. Such tests can sway judges or juries and influence whether someone gets custody of a child or is eligible for bail or capital punishment.

The scientists looked at hundreds of psychological tests used in recent court cases and found that a third of those exams weren’t reviewed in the field’s most prominent manuals. Of those that were reviewed, just 40% were graded favorably. Nearly a quarter were deemed unreliable.

“There’s huge variability in the psychological tools now being admitted in U.S. courts,” said Tess Neal, an Arizona State University psychology professor and co-author of the study published Saturday in the journal Psychological Science in the Public Interest.

“There’s a lot of stuff that looks like it’s junk and should be filtered out by the courts, but it’s not being filtered out,” said Neal.

Legal challenges to the validity of psychological tests occurred in less than 3% of cases, the researchers found.

“This paper is highly significant, in part because many people’s fates are determined by these tests,” said Dan Simon, an expert on law and psychology at the University of Southern California Law School, who was not involved in the research.

The new study is not the first critique of how science is used in the courts.

In 2009, the National Research Council released an extensive report on courtroom science that found that “testimony based on faulty forensic science analyses may have contributed to wrongful convictions of innocent people.”