Man, wish I could find the link - I had read something probably 10 years ago that discussed the abnormally high number of independently wealthy people in academia and research. Makes sense given how expensive it is and how infrequently it nets positive ROI.
A big part of science are 'ideas', and ideas are interesting things in Human culture. To be the 'idea person' in a social group requires considerable social status. I see so many people in corporations battling to have their ideas win. I see so many people of higher status claiming ownership of the ideas of those 'beneath' them. I see plenty of great ideas being ignored because of who proposes them. And, it's very rare to see an outsider's idea gain influence.
They say that execution matters much more than ideas - but they go hand-in-hand. The person who gets to execute also gets to choose the idea.
Given the comparitive physical weakness of the Human, 'the idea' is their number one weapon and asset. It enables power. So, there are probably a lot of social reasons why most lower-status (lower income) people are kept out of science and research. It's probably more of a systematic result of Human behavior than just being poor.