Back in Tilburg, Stapel sank into a deep depression. Through the winter he filled a series of Moleskine diaries with reflections on his life. It was an accounting exercise encouraged by his therapist. Forgiven by his wife, Stapel wondered if he would ever be forgiven by those he had damaged the most — his students and postdocs.

A few reached out. One day in December 2011, Saskia Schwinghammer, a former student and now a researcher at the University of Applied Sciences in Utrecht, visited him at his home. Stapel wept as he apologized. He reminded her that she and other students were in no way to blame, that they did not have to feel they should have been more discerning when accepting data from him. “You came up with these ideas,” Stapel told her. “You designed the studies. I took away one little thing from the process. Don’t let people think that you’re worthless because you worked with me.”

Schwinghammer left teary-eyed. “It was good to have seen you,” she said. A year later, she told me she had forgiven the man but not his actions. “There are good people doing bad things,” she said, “there are bad people doing good things.” She put Stapel in the former category.

At the end of November, the universities unveiled their final report at a joint news conference: Stapel had committed fraud in at least 55 of his papers, as well as in 10 Ph.D. dissertations written by his students. The students were not culpable, even though their work was now tarnished. The field of psychology was indicted, too, with a finding that Stapel’s fraud went undetected for so long because of “a general culture of careless, selective and uncritical handling of research and data.” If Stapel was solely to blame for making stuff up, the report stated, his peers, journal editors and reviewers of the field’s top journals were to blame for letting him get away with it. The committees identified several practices as “sloppy science” — misuse of statistics, ignoring of data that do not conform to a desired hypothesis and the pursuit of a compelling story no matter how scientifically unsupported it may be.

The adjective “sloppy” seems charitable. Several psychologists I spoke to admitted that each of these more common practices was as deliberate as any of Stapel’s wholesale fabrications. Each was a choice made by the scientist every time he or she came to a fork in the road of experimental research — one way pointing to the truth, however dull and unsatisfying, and the other beckoning the researcher toward a rosier and more notable result that could be patently false or only partly true. What may be most troubling about the research culture the committees describe in their report are the plentiful opportunities and incentives for fraud. “The cookie jar was on the table without a lid” is how Stapel put it to me once. Those who suspect a colleague of fraud may be inclined to keep mum because of the potential costs of whistle-blowing.

The key to why Stapel got away with his fabrications for so long lies in his keen understanding of the sociology of his field. “I didn’t do strange stuff, I never said let’s do an experiment to show that the earth is flat,” he said. “I always checked — this may be by a cunning manipulative mind — that the experiment was reasonable, that it followed from the research that had come before, that it was just this extra step that everybody was waiting for.” He always read the research literature extensively to generate his hypotheses. “So that it was believable and could be argued that this was the only logical thing you would find,” he said. “Everybody wants you to be novel and creative, but you also need to be truthful and likely. You need to be able to say that this is completely new and exciting, but it’s very likely given what we know so far.”

Fraud like Stapel’s — brazen and careless in hindsight — might represent a lesser threat to the integrity of science than the massaging of data and selective reporting of experiments. The young professor who backed the two student whistle-blowers told me that tweaking results — like stopping data collection once the results confirm a hypothesis — is a common practice. “I could certainly see that if you do it in more subtle ways, it’s more difficult to detect,” Ap Dijksterhuis, one of the Netherlands’ best known psychologists, told me. He added that the field was making a sustained effort to remedy the problems that have been brought to light by Stapel’s fraud.