Yes. Jeff Bezos parents gave him a loan of $245,573, in 1993 money to start Amazon. This indicates that he grew up if not very wealthy, but solidly on the upper side of middle class. Growing up poor he would've probably not had the opportunities to get into Princeton (statistically), so probably would have had a harder time breaking in the hedge fund industry, giving him less cash on hand, and probably wouldn't have started Amazon. Maybe growing up poor he could have, but its more likely as a smart ambitious poor person, he'd have gone to whatever school gave him a good scholarship, and then ended up as an Engineer or some other safe profession and landed middle class.
Being born rich lets you take a lot more risks.