Yes it's in America, and things are different over there. However they do have similar diversity challenges when it comes to the workplace.

Below you'll find a link to a 36 page PDF, which almost entirely supports other content and reports I've found on the web (and shared here).

What's really interesting is that this is a company that has taken a very scientific approach, and not a university study.

The most impactful paragraph for me is the one below which you can find on page 18. If you're short on time, skip to page 17 and read the conclusion.

Essentially if you truly value diversity. Don’t tell people. Show people, if you can (just not in a cheesy, overly obvious way).