In my opinion, this is not at all different between rich people and poor people because the risks are basically the same. Even though rich people will remain calm and will not experience difficulties when they lose at gambling, poor people will definitely have difficulties and can even immediately experience difficulties when they lose at gambling. So I think that's the small difference between a rich person and a poor person who loses a gambling bet at the same place.
But don't you think weather remaining calm either as a poor or rich person is a product of how much such individual gambled it, because you just can't expect a rich man who earns $1000 monthly and gambled $10 on a bet and lost it to worry, unlike a poor man who earns $50 monthly and then went and gamble same $10 not to be madly worry about his lose, because just as $10 is 1% of $1000, if the same poor man gambles same 1% of his income, which is $0.5 and lost it.. Do you think such poor man will be angry?
You have a point there, but first, I still do not categorise the person earning barely $1,000 rich, but the way you relate that money with betting is quite fair and understood. If one is earning $1,000 and risks $10 out of it for gambling, that means the person is risking just 1% of his earnings. This can't in any way affect the person much. Unless such is risking it over and over again when losing, but if the 1% is the monthly budget for gambling, and such which the person adheres strictly to, then it will not in a way affect him and he will be gambling reasonably and not with emotion. As a matter of fact, the person who could be using 1% of his total earnings to gamble has already concluded in his mind that he is not making wealth out of gambling, if not, more money would have been committed to it than that, and I am talking of at least 10% of his monthly income.
But not doing that means that such is gambling with the amount of money he can afford to lose, and this also means that there is less hassle and desperation to gambling and making money through it, which is the best practice that can make gamblers stay responsible and also not get addicted to it. But for the poor who earn less and gamble more, it is an issue, there is no way such will not want to make money through gambling by all means (desperation), and that mindset alone is enough to kill the account of the gambler and make him reckless at the same time. Above all, since the rich will make more money than the poor and still have enough to fall back on when they lose, they will always have a better mindset towards gambling, and hence, better gamblers than the poor in my opinion.