After a two-year federal investigation, the Office of Research Integrity found former Harvard psychology professor Marc D. Hauser responsible for six counts of research misconduct, including fabrication of data, doctoring of results, and misrepresentation of research methods in his Harvard lab.

In a public statement, Hauser said that although he does not agree with the entirety of the report, he accepts full responsibility for errors made when he was head of the laboratory. He attributed many of those faults to his taking on too much responsibility at the University.

“I tried to do too much, teaching courses, running a large lab of students, sitting on several editorial boards, directing the Mind, Brain & Behavior Program at Harvard, conducting multiple research collaborations, and writing for the general public,” he wrote. “I let important details get away from my control, and as head of the lab, I take responsibility for all errors made within the lab, whether or not I was directly involved.”

The two-year inquiry came to an end today when the Department of Health and Human Services posted its official notice online. According to the report, Hauser’s research misconduct affected work—both published and unpublished—funded by four different national agencies, including the National Institutes of Health and the National Institute of Mental Health.

Hauser, whose research primarily concerned animal cognition and moral psychology, maintains that much of the doubt surrounding his research is unmerited.

“I am saddened that this investigation has caused some to question all of my work, rather than the few papers and unpublished studies in question,” he wrote. “Before, during and after the investigation, many of my lab’s research findings were replicated by independent researchers. I remain proud of the many important papers generated by myself, my collaborators and my students over the years.”

Harvard conducted an internal review of Hauser’s work that preceded the national investigation by three years. After the Boston Globe announced that Hauser was taking a one-year leave of absence due to an investigation into the integrity of his work, Dean of the Faculty of the Arts and Sciences Michael D. Smith confirmed in Aug. 2010 that a Harvard committee had found Hauser “solely responsible” for eight instances of misconduct.

Since Harvard’s investigation, Hauser retracted or corrected three of the published articles found to be problematic. In more than one case, he and his associates also replicated findings and published their work again.

The new ORI report acknowledged these changes but still found the original papers faulty.

“As Dean Smith said two years ago, no university or college wants to see a member of the faculty found responsible for research misconduct, for such misconduct strikes at the core of our academic values,” FAS spokesperson Jeff Neal wrote in a statement.

Bert Vaux, a former associate professor of linguistics at Harvard who in 2010 criticized the handling of the case, wrote to The Crimson that although he finds the report “clear and in certain ways reasonable,” he finds the amount of money invested in investigating Hauser’s case by Harvard and the government unwarranted, given that “the identified problems were all either retracted or never submitted.” Vaux communicated via email because he was traveling without access to a cell phone.

Hauser resigned from his tenured position on the Faculty of Arts and Sciences in July 2011 after colleagues on the faculty voted to bar him from his teaching duties. In his statement on Wednesday, he called the investigation “long and painful” and added that he is “relieved” it is finally complete.

Since leaving Harvard, he wrote, he has turned his attention to working with at-risk youth.

Although Hauser “neither admits nor denies committing research misconduct,” according to the ORI report, he has agreed to supervision for any new government-sponsored research he conducts, review and public disclosure to funding agencies of the legitimacy of his data by institutions that employ him in the future, and exclusion from advisory responsibilities to the U.S. Public Health Service.

—Staff writer Radhika Jain can be reached at radhikajain@college.harvard.edu.