Small differences in competitive situations can make a big difference. That was the conclusion of Professor Avner Ben-Ner and his coauthors, Drs. John-Gabriel Licht and Jin Park, after analyzing diversity’s impact on every play and every player in 10 years of matches in the Bundesliga, Germany’s top soccer league.

“Controlling for the ability of the players, the effect of diversity is positive among defenders,” says Ben-Ner. “Greater diversity advances the ability to prevent goals and improves the performance of individuals and the team.”

However, the researchers found very different results among those in the role of attacking.

“The greater the diversity in offense, the lower the outcome, both at the team and individual level,” he adds.

Ben-Ner says the unfavorable impact of diversity often appears in minor, diluted ways. Maybe in one of 20 circumstances where the situation calls for passing to a teammate of a different ethnicity, the player may, consciously or subconsciously, elect not to. This occurs because the individual incentives are stronger in offense, making cooperation less likely among members of different groups.

In the defense or prevention role, he says the ethnic or linguistic differences are muted by the instinct to close ranks, to unify.

“What remains is the positive effect of creativity, enhanced by different perspectives, different experiences, different thought processes."

While noting the small positive and negative impact of diversity on the different roles, he quickly adds that the research does not simply suggest teams would benefit by having less diversity in offense, or in companies with similar roles that entail promotion rather than prevention. Instead, Ben-Ner says, maintaining the benefits of diversity via creativity while working on reducing communication problems and antagonism between various groups will generate positive benefits from diversity, as it is in defense roles.

Ben-Ner says the findings from the soccer pitch show that in complex, interdependent settings the ability to take advantage of the positive impact of diversity and mitigate the negative effect can be the difference between winning and losing.