In court, far-reaching psychology tests are unquestioned

February 15, 2020

Psychological tests are important instruments used in courts to aid legal decisions that profoundly affect people's lives. They can help determine anything from parental fitness for child custody, to the sanity or insanity of a person at the time of a crime, to eligibility for capital punishment.

While increasingly used in courts, new research shows the tests are not all scientifically valid, and once introduced into a case they are rarely challenged, according to Tess Neal, an assistant professor of psychology at Arizona State University.

"Given the stakes involved one would think the validity of such tests would always be sound," Neal said. "But we found widespread variability in the underlying scientific validity of these tests."

The problem is made worse because the courts are not separating the good from the bad.

"Even though courts are required to screen out 'junk science,' nearly all psychological assessment evidence is admitted into court without even being screened," Neal said.

Neal was speaking today (February 15) at the annual meeting of the American Association for the Advancement of Science in Seattle. She presented her findings in the talk "Psychological assessments and the law: Are courts screening out "junk science?"

In a two-part investigation, Neal and her colleagues found a varying degree of scientific validity to 364 commonly used psychological assessment tools employed in legal cases. The researchers looked at 22 surveys of experienced forensic mental health practitioners to find which tools are used in court. With the help of 30 graduate students and postdocs, they examined the scientific foundations of the tools, focusing on legal standards and scientific and psychometric theory.

The second part of the study was a legal analysis of admissibility challenges with regard to psychological assessments, focusing on legal cases from across all state and federal courts in the U.S. for a three-year period (2016-2018).

"Most of these tools are empirically tested (90%), but we could only clearly identify two-thirds of them being generally accepted in the field and only about 40% as having generally favorable reviews of their psychometric and technical properties in authorities like the Mental Measurements Yearbook," Neal explained.

"Courts are required to screen out the 'junk science,' but rulings regarding psychological assessment evidence are rare. Their admissibility is only challenged in a fraction of cases (5.1%)," Neal said. "When challenges are raised, they succeed only about a third of the time."

"Challenges to the most scientifically suspect tools are almost nonexistent," Neal added. "Attorneys rarely challenge psychological expert assessment evidence, and when they do, judges often fail to exercise the scrutiny required by law."

What is needed is a different approach. In their open-access paper in Psychological Science in the Public Interest, Neal and her colleagues offer concrete advice for solving these problems to psychological scientists, mental health practitioners, lawyers, judges and members of the public interacting with psychologists in the legal system.

"We suggest that before using a psychological test in a legal setting, psychologists ensure its psychometric and context-relevant validation studies have survived scientific peer review through an academic journal, ideally before publication in a manual," Neal explained. "For lawyers and judges, the methods of psychologist expert witnesses can and should be scrutinized, and we give specific suggestions for how to do so."
Skip Derra
Media Relations & Strategic Communications
Arizona State University

Arizona State University

Related Psychology Articles from Brightsurf:

More than one cognition: A call for change in the field of comparative psychology
In a paper published in the Journal of Intelligence, researchers argue that cognitive studies in comparative psychology often wrongly take an anthropocentric approach, resulting in an over-valuation of human-like abilities and the assumption that cognitive skills cluster in animals as they do in humans.

Psychology research: Antivaxxers actually think differently than other people
As vaccine skepticism has become increasingly widespread, two researchers in the Texas Tech University Department of Psychological Sciences have suggested a possible explanation.

In court, far-reaching psychology tests are unquestioned
Psychological tests are important instruments used in courts to aid legal decisions that profoundly affect people's lives.

Psychology program for refugee children improves wellbeing
A positive psychology program created by researchers at Queen Mary University of London focuses on promoting wellbeing in refugee children.

Psychology can help prevent deadly childhood accidents
Injuries have overtaken infectious disease as the leading cause of death for children worldwide, and psychologists have the research needed to help predict and prevent deadly childhood mishaps, according to a presentation at the annual convention of the American Psychological Association.

Raising the standard for psychology research
Researchers from Stanford University, Arizona State University, and Dartmouth College used Texas Advanced Computing Center supercomputers to apply more rigorous statistical methods to psychological studies of self-regulation.

Psychology: Robot saved, people take the hit
To what extent are people prepared to show consideration for robots?

Researchers help to bridge the gap between psychology and gamification
A multi-disciplinary research team is bridging the gap between psychology and gamification that could significantly impact learning efforts in user experience design, healthcare, and government.

Virtual reality at the service of psychology
Our environment is composed according to certain rules and characteristics which are so obvious to us that we are scarcely aware of them.

Modeling human psychology
A human being's psychological make-up depends on an array of emotional and motivational parameters.

Read More: Psychology News and Psychology Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to