So my question is, is the percentage of the rich gambling lower than the middle and lower class?
Well the number of rich people that gambles would always be lesser than the poor because it obvious that our society is filled with more poor or average than rich, asides that majority of the poor vies gambling as an alternative to getting rich quick and would always fall back to try their luck when they run out of options, and I think your friend was right when he said most people are addict to gambling for the love of it and not mostly because of money, whereas a poor man's reason for gambling addiction would always fall back to making money.