The dirty secret of all science. People only study things that someone will pay for. And often the questions that you or I would like to see answered never attract funding. Recently someone discovered that booth babes do not work as a marketing tool by spending their own company's money on some experiments. Unfortunately this kind of thing is rare in the public eye.
Some people think that Google has done such studies but they are part of its secret sauce.
I've heard Google has a special process, unfortunately even if they make it public, it would only help startups in a very limited scope. The hiring requires are different, especially when it comes to a lot of the "soft skills".
Some people think that Google has done such studies but they are part of its secret sauce.