Dr. Hauser’s fall from grace, if it occurs, could cast a shadow over several fields of research until Harvard makes clear the exact nature of the problems found in his lab. Last week, Dr. Smith, the Harvard dean, wrote in a letter to the faculty that he had found Dr. Hauser responsible for eight counts of scientific misconduct. He described these in general terms but did not specify fabrication. An oblique sentence in his letter said that the Cognition paper had been retracted because “the data produced in the published experiments did not support the published findings.”

Scientists trying to assess Dr. Hauser’s oeuvre are likely to take into account another issue besides the eight counts of misconduct. In 1995, Dr. Hauser published that cotton-top tamarins, the monkey species he worked with, could recognize themselves in a mirror. The finding was challenged by the psychologist Gordon Gallup, who asked for the videotapes and has said that he could see no evidence in the monkey’s reactions for what Dr. Hauser had reported. Dr. Hauser later wrote in another paper that he could not repeat the finding.

The small size of the field in which Dr. Hauser worked has contributed to the uncertainty. Only a handful of laboratories have primate colonies available for studying cognition, so few if any researchers could check Dr. Hauser’s claims.

“Marc was the only person working on cotton-top tamarins so far as I know,” said Alison Gopnik, a psychologist who studies infant cognition at the University of California, Berkeley. “It’s always a problem in science when we have to depend on one person.”

Many of Dr. Hauser’s experiments involved taking methods used to explore what infants are thinking and applying them to monkeys. In general, he found that the monkeys could do many of the same things as infants. If a substantial part of his work is challenged or doubted, monkeys may turn out to be less smart than recently portrayed.

But his work on morality involved humans and is therefore easier for others to repeat. And much of Dr. Hauser’s morality research has checked out just fine, Dr. Haidt said.

“Hauser has been particularly creative in studying moral psychology in diverse populations, including small-scale societies, patients with brain damage, psychopaths and people with rare genetic disorders that affect their judgments,” he said.