When it comes to issues of race, gender, and diversity in organizations, researchers have revealed the problems in ever more detail. We have found a lot less to say about what does work — what organizations can do to create the conditions in which stigmatized groups can reach their potential and succeed. That’s why my collaborators — Nicole Stephens at the Kellogg School of Management and Ray Reagans at MIT Sloan — and I decided to study what organizations can do to increase traditionally stigmatized groups’ performance and persistence, and curb the disproportionately high rates at which they leave jobs.

One tool at any organization’s disposal is the way its leaders choose to talk (or not to talk) about diversity and differences — what we refer to as their diversity approach. Diversity approaches are important because they provide employees with a framework for thinking about group differences in the workplace and how they should respond to them. We first studied the public diversity statements of 151 big law firms in the U.S. to understand the relationship between how organizations talk about diversity and the rates of attrition of associate-level women and racial minority attorneys at these firms. We assumed that how firms talked about diversity in their statements was a rough proxy for their firm’s approach to diversity more generally.

Two findings were particularly intriguing. First, there are two fundamentally different ways that diversity statements seek to appeal to the stigmatized groups they target. One appeal is to differences and how differences are important. We call this the “value in difference” approach. For example, a value in difference approach advocates for increasing awareness of differences and bias, and signals the organization’s belief that these differences not only improve employees’ experiences in the workplace, but also advance the firm’s bottom-line goals. The other approach is an appeal to equality and fairness irrespective of differences. We call this the “value in equality” approach. For example, a value in equality approach affirms that differences will not be an obstacle to career opportunities and advancement, and that all employees are judged equally and fairly based on their skills, qualifications, and effort.

The second key finding was that there was no evidence that one of these two approaches was more effective than the other overall. But the effectiveness of each approach (in this case, meaning its association with reduced rates of attrition) depended on whether we looked at women or racial minorities.

In fact, our data suggested that women and racial minorities not only responded differently to these two diversity approaches, but that each group responded in virtually the opposite way. The more firms emphasized the value in difference approach, the lower the rates of attrition among women, whereas the more firms emphasized the value in equality approach, the lower the rates of attrition among racial minorities.

What can explain these divergent responses to the same statements? We think one major factor is the difference in numerical representation of women and racial minorities in these firms (and most professional settings). Although women and racial minorities are often considered under the same umbrella of stigmatized groups, the fact of the matter is that in the U.S., white women often comprise close to 40% of all employees in professional settings, whereas black women and men, by contrast, rarely comprise more than 5% of employees in these same settings. The key to understanding our results, we believe, is appreciating that the difference in the relative size of these groups influences how concerned they are with “sticking out” as representatives of their group. While the value in difference approach may energize groups, like white women, who are represented in moderate numbers—helping affirm the importance of their different background and perspectives to the firm—the very same message may, ironically, undermine groups who are represented in very small numbers, like black women and men. Even well-intentioned efforts to “value differences” may only fuel concerns among black women and men that others will think their position, promotion, or positive evaluation is due to their race, rather than their qualifications or competence. The value in equality approach is more effective for groups in very small numbers as it makes them feel less distinct from others while affirming a commitment to equal and fair access to opportunities.

If numerical representation is really the factor that shapes what is desirable and effective in a diversity approach, then what would happen if black women and men made up 40% of the firm? Or if white women were 5% of the firm? We ran a controlled experiment with white and black professionals to test these very questions. We asked these professionals to review web content from the perspective of an employee who had earned a spot in an elite consulting firm. Half of these professionals were told that they were part of a group that constituted 5% of the firm, whereas the other half were told that they were part of a group that constituted 40% of the firm. We then presented them with either a prototypical value in difference or value in equality approach and measured their performance and persistence on a challenging cognitive task. What we found is that when professionals believed that they were part of the 5% group, the value in equality approach led to greater performance and persistence than the value in difference approach—regardless of whether they were white women or black. When professionals believed that they were part of the 40% group, we saw the reverse pattern: the value in difference approach led to greater performance and persistence than the value in equality approach—regardless of their race or gender. This evidence suggests that numbers play a critical role in determining which diversity approach is best.

What does this all mean? For one, I think it means that no approach to talking about differences and diversity will work uniformly well across groups and contexts. Before organizations decide to focus on the value in difference or equality, they should first consider who they are targeting, and how numerical representation and corresponding concerns may shape their responses.

One big practical challenge raised by this work is what an organization should do if it wants to improve the situation for both women and minority groups. Is it possible both to emphasize the value in difference and equality?

We found some evidence that the positive relationships we observed (between more focus on value in difference and less female attrition and between more focus on value in equality and less minority attrition) disappear in firms that try to emphasize both approaches. Understanding why this is the case will require more study, but it seems logical that saying that you care about differences and think they are important — and at the same time, you don’t — could both dilute the broader message and come across as inauthentic.

This research suggests a way to align traditional business objectives of boosting performance and stemming turnover with the goal of helping all groups have the same opportunities to succeed.