Diversity might be a good thing, but forced training in tolerance not only fails in the business world, it backfires, according to a new Harvard study.

Managers sent to mandatory diversity training sessions often come away resenting the very groups they are being encouraged to accept, according to the study, entitled “Why Diversity Programs Fail,” and published in the latest edition of Harvard Business Review. It gets even worse when threats and punishments are imposed to ensure participation, the study found.

“People often respond to compulsory courses with anger and resistance,” wrote authors Frank Dobbin, a professor of sociology at Harvard and Alexandra Kalev, a professor of social sciences at Tel Aviv University. “Your organization will become less diverse, not more.”

The study looked at financial institutions, where in mandatory initiatives aimed at increasing diversity have not increased the number of white women and black men in managerial positions, the study claims. Five years after implementation of involuntary training, the proportion of minority managers either remained stagnant or declined — as much as 9 percent for black women.

“Mandatory diversity training sends exactly the message of control - and psychological research shows us time and time again [that] people resist control,” Kalev told FoxNews.com in an email.

On the other hand, the option to undergo voluntary training invoked the opposite effect- minority representation in management increased, around 4 percent for black men. The study found that when training is not forced on employees, as many as 80 percent take part – and the benefits are measurable.

Large banks and other big companies shell out millions of dollars every year for diversity training programs, in part to guard against discrimination lawsuits. Morgan Stanley budgeted an additional $7.5 million toward diversity programs in 2007 after getting hit hard with multiple discrimination lawsuits, Bloomberg News reported, in settlements that cost the company more than $100 million in the past few decades.

But ineffective training will not protect companies from legal exposure, said attorney Suzanne Bish, who litigated a discrimination suit against an investment bank.

“It doesn’t mean very much to us if there’s diversity training or not,” she said. “There are companies who want to appear that they are doing something, and it could be window dressing.”

The study’s findings did not surprise Bish, who said forced training could cause employees to “get defensive” and that people often “don’t react in a positive way to that training,” especially if higher-ups aren’t perceived as authentic in their diversity beliefs.

The study also has implications for college campuses, where mandatory diversity programs and voluntary courses have increasingly expanded from coast to coast.

In one of the more aggressive programs, the University of Toledo will implement elements of its Strategic Plan for Diversity and Inclusion, which will require all faculty and students to enroll in diversity training by the 2017 school year. The plan is proceeding even though two-thirds of students who had never had diversity training said they were opposed to it. Forcing those students to participate would be counterproductive, according to Kalev.

As in the business world, mandatory diversity training could cause members of the campus community to “disengage from the idea of diversity” and “develop negative attitudes toward minority students and faculty” she warned.