There are an awful lot of variables, but I don’t doubt that wealth and empathy are negatively correlated. I do believe that a lack of empathy makes it easier for someone to get ahead because it often takes a sort of competitive ruthlessness to get ahead in a capitalist system.
I used to work for some very wealthy people many years ago, and it was always amusing to watch them calculate tips and other types of compensation for people who served them. They were FAR stingier than most “poor” people when it came to tipping, etc. Of course, they would argue that being stingy is how one accrues wealth and gets ahead (and they’d be right). Just something that really struck me back then.
Of course, after calculating an exact 10% tip for the overworked waitress who just served their party of 12 (and they’d complain more than most patrons, too), they would spend $100K+ on a new car for themselves, or do an $80K+ remodel on their kitchens every three years or so (and this was back in the 80s).
Another possibility is that people who are very successful need to feed the belief that they “did it all by themselves through hard work,” etc. If they were to honestly consider the role of luck in their good fortune, it would become apparent that their luck could run out just as easily. It’s frightening to think about, so they create a story in their heads that they are “different” and “more deserving” by default. If they empathize too much with those on the lower rungs, they will too easily see that, “there, but for the grace of God, go I,” so they distance themselves from those less fortunate.
And since truly successful people have to maintain their social networks (another major factor where most wealth is concerned), they can’t be seen associating with the “little people” unless it’s for some sort of charitable cause. They have to maintain the image — both for themselves and the other social climbers who surround them — that they are really and truly superior to the struggling masses.