I think one should take a closer look at those McKinsey studies - they cite them after all!
https://www.mckinsey.com/~/media/mckinsey/featured%20insights/diversity%20and%20inclusion/diversity%20wins%20how%20inclusion%20matters/diversity-wins-how-inclusion-matters-vf.pdf
Here’s the first author:
Prior to joining McKinsey, Sundiatu worked with a leading Swiss pharmaceuticals company as a senior project manager in drug development, and with Geneva University Hospital as a clinical research coordinator.