A leading psychopathy researcher has used the threat of legal action to have changes made to a research paper critical of a widely used criminological rating scale he developed 20 years ago. In the process the paper, which was accepted for publication in 2007 by Psychological Assessment, was delayed three years. It finally appeared in the journal's June issue, but the whole affair has raised questions about how legal threats can impact the progress of psychological science.

The article in question concerns the Hare Psychopathy Checklist–Revised (PCL-R), which is commonly administered in serious criminal cases to help make sentencing decisions as well as in prisons and psychiatric hospitals to determine suitability for release. A high score on the PCL-R is used to diagnose psychopathy.

People familiar with the matter say the scale's author, Robert Hare of the University of British Columbia, deserves only partial blame for the delay, to be shared with the American Psychological Association (APA), the journal's publisher. But they say Hare's use of legal threats has at best subverted the peer review process that is the crux of modern scientific progress, and could at worst encourage junior researchers in the field of forensic psychology to pursue other lines of research.

"I find this action to be completely inconsistent with the man I had [great] respect and affection for," says Stephen Hart of Simon Fraser University in British Columbia, a collaborator and former student of Hare's. "People I speak with automatically think, 'Well, what's in that article that makes him so upset? What's he so afraid of?'"

In their finally published critique of the Hare checklist, Jennifer Skeem of the University of California, Irvine, and David Cooke of Glasgow Caledonian University argue that forensic psychologists and psychiatrists have wrongly come to view the PCL-R as a complete description of psychopathy. They say it leaves out certain characteristics such as low anxiety that are central to the disorder and focuses too much on criminal behavior. These features may "promote overdiagnosis of psychopathy," they wrote.

According to a document Hare has circulated to journalists and other researchers, Skeem and Cooke's original manuscript misrepresented Hare's work by incorrectly paraphrasing a 2005 paper published in Current Psychiatry Reports, taking words out of context from it and other papers to support the argument that researchers have viewed criminal behavior as "important" or "central" to psychopathy.

Based on this disagreement and others Hare and a colleague lobbied a senior editor of Psychological Assessment to get Skeem and Cooke to reexamine their paper, which had already passed peer review, and make revisions. But Hare says the subsequent revisions were minimal, and after consulting with his lawyer he threatened to sue for defamation if the paper was published in its then current form. The APA then appointed a new group of editorial reviewers, who requested additional changes from the authors. "It was [a] shock," Skeem says of Hare's legal threat. "This is not about Professor Hare, and it's only incidentally about the Psychopathy Checklist," she says. "The focus was really on how we could move the field forward." Skeem says she now worries that papers she submits for review will be labeled as biased.

The situation could have been worse: In 2008 the British Chiropractic Association sued U.K. writer Simon Singh for libel after he wrote in the Guardian that the group "happily promotes bogus treatments." Although a judge initially ruled that Singh's words constituted an assertion of fact, which would have made it hard for him to win a trial case, in April 2010 an appeals court found that his statement qualified as "fair comment" and was therefore protected. Back in the academic world APA publisher Gary VandenBos says he has fielded 20 to 30 legal threats similar to the current one in his 25-year tenure. "The APA has always published any article that was challenged," VandenBos says, "but APA…has a responsibility to all parties to evaluate a legal claim."

The current case became more widely known after a commentary on it appeared in the International Journal of Forensic Mental Health (IJFMH), written by two researchers at the University of South Florida in Tampa—Norman Poythress, who frequently collaborates with Skeem, and John Petrila. They argue that threats such as Hare's "strike at the heart of the peer review process" and "may have a chilling effect on the values at the core of academic freedom."

In an academic disagreement, "filing a defamation suit…may be the last response in extreme cases," Petrila says, "but you have to search for a long time before finding a case in which a threat to sue is the first or an early response."

Hart, who edits IJFMH, says Hare has a vested interest in the PCL-R because he receives significant royalties from it. Hare counters that if money was his goal, he could have made much more by testifying in high-profile criminal cases as some of his colleagues do. He says he receives less than $35,000 annually for royalties associated with the PCL-R and its derivatives.

Hare says his side of the matter has not been heard. "The APA would not have done anything had my complaint not been valid," he says. "Obviously there was something wrong to start with." In the document he has circulated he questions why Poythress and Petrila did not seek his version of events before writing their commentary and why Hart did not offer Hare a chance to respond in the same issue of IJFMH.

Other researchers are more concerned with the effects of Hare's actions on the field, although not all of them are convinced those effects will be enduring. "The reaction to this, and the way this has sort of unfolded, I don't think [it] leaves anyone thinking litigation is helpful," says forensic psychologist Daniel Murrie of the University of Virginia, who was not involved in the dispute.

Hart says he would like to see everyone put the "disturbing and embarrassing" matter behind them. "We need to get over this part of it as quickly as possible and get back to science."