During the past five years, the business press has reported on several studies indicating that organizations with a more diverse workforce than their competitors are more effective and profitable. The most recent study, conducted by McKinsey & Co. and highlighted last week in the Wall Street Journal, indicated that “businesses with the most gender diverse leadership were 15% more likely to report financial returns above their national industry median”, and that this figure rose to 35% with a large-enough cadre of ethnically-diverse leaders.

I inwardly cringe when I come across these studies because the place at which I worked that had the highest percentage of people from diverse backgrounds, a call center of a large federal government agency, was by far the most dysfunctional. Race-baiting among African Americans and white people was common, with management taking the lead. The group of visually-impaired people to which I belonged would often say to each other just loud enough for others to hear that the black people hated the white people; the white people hated the black people; and everybody hated us. We led the cheers when a manager announced to the entire staff at the end of one especially bad year that the national office had ranked our call center as the worst in the United States.

Compare this call center with the Columbia Chorale, a community chorus that I have been a member of since 2009: a mixture of men and women led first by a man who is gay followed by two women. Over the years, we have taken on more challenging repertoire in an atmosphere of professional camaraderie.

What distinguishes the ever-worsening call center from the steadily improving Chorale, and what factors make it more likely that organizations can take advantage of the diversity dividend? I suggest two.

* A clearly-defined mission that leaders both communicate and model. While we were supposed to be providing quality customer service at that dysfunctional call center, both managers and those they managed were contemptuous towards the customers we were paid to assist. “All customers are liars,” was a common refrain of my first boss, and most supervisors were even ruder to customers than we were. By contrast, Columbia Chorale members understand why we rehearse most Monday evenings, and the conductors reinforce this commitment by running well-organized rehearsals, acknowledging their mistakes with grace and humor, communicating clearly, and showing confidence in our abilities as they challenge us to get better.

* An ability and willingness to address — and sometimes even welcome — small and large conflicts when they emerge. Consider the differences between how a conflict between a visually-impaired male and a woman leader was addressed at the call center and in the Chorale.

At the call center, another blind employee was rude to both customers and colleagues. His guide dog stole food from tables and signaled the end of the workday with a loud bark. One day, he returned from lunch with a bottle of wine, and encouraged us to drink with him. At day’s end, a blind colleague complained to his boss, and was told: “What am I supposed to do? The guy is blind.”

By contrast, the Columbia Chorale’s conductor asked that another baritone and I sing a four-measure phrase together during a Fourth of July concert. During the concert intermission, I was reading a magazine while listening to the rest of the choir’s babble until the conductor appeared at my side to tell me that my voice wasn’t blending well with that of my partner’s. “How do you view the phrase you’re singing?” she asked.

“Ah,” I stammered, trying to figure out the answer she wanted. “The only word I really want to stress is the word `bite.`”

Suddenly, I realized that I was singing the entire phrase with the “bite” vibe in my voice. I explained this to the conductor, apologized for my lack of musicianship, and smoothed out my voice during the performance. The phrase sounded better, especially to my ears.

The research is clear that a diverse workforce, supported by a diverse cadre of leaders, improves both organization effectiveness and its bottom line. But this dividend will turn into a millstone unless a clear mission and a good-enough ability to address conflicts are in place. Strengthening these building blocks will benefit everyone, especially people from diverse backgrounds.