A lot of the effects were clustered right around zero

From Finally Some Robust Research Into Whether “Diversity Training” Actually Works – Unfortunately It’s Not Very Promising by Jesse Singal.

The methodology of the research is weak so not too great store can be set on the findings one way or another.  

For a new paper in PNAS, a prominent team of researchers, including Katherine Milkman, Angela Duckworth, and Adam Grant of the University of Pennsylvania’s Wharton School, partnered with a large global organisation to measure the real-world impact of the researchers’ own anti-bias intervention, designed principally to “promote inclusive attitudes and behaviors toward women, whereas a secondary focus was to promote the inclusion of other underrepresented groups (e.g., racial minorities).” The results were mixed at best – and unfortunately there are good reasons to be sceptical that even the more positive results are as positive as they seem.

The company in question emailed 10,983 employees, inviting them to “complete a new inclusive leadership workplace training,” as the researchers sum it up. Out of those, 3,016 employees, 38.5 per cent of them American, answered the call and were assigned, in thirds, either to one of two online treatment groups or to a control group.

The researchers measured changes in the attitudes of the participants in the training and found some modest effect size.

More critically, when they measured actual changes in behavior, the results were bleak.

Meanwhile, the behavioral results (based on participants’ choices of who to mentor, which new hires to speak to, and colleagues’ excellence to recognise) were far less impressive than the attitudinal ones. A lot of the effects were clustered right around zero and/or differed greatly on the basis of sex or nationality (which isn’t a good sign for programmes that are designed to be delivered to large, diverse groups of employees). The biggest effect involved an email invitation, 14 weeks after follow-up, to talk on the phone with either a male or a female new hire. There was no overall effect, but among women only, those in the bias-training group were more likely, at a statistically significant level, than those in the control condition, to agree to talk to newly hired women than men.

A weak study showing near zero effect sizes is not much of a peg to hang a confident hat on.  But it is reasonably consistent with other emerging evidence on diversity training.  They don't work and not infrequently exacerbate tensions.

No matter the good intentions, it appears that trying to make people more racially self-aware is not a particularly beneficial or progressive achievement.