I cannot say that the religious are more selfish. As a former Muslim the worldview was that man was just a slave of Allah and not worthy of anything. It heavily denigrates the role of man to be akin to disposable trash. You can't take Christian theology and lump it with all religion since Christianity and its various flavors drastically differ in approach. I can't fathom a selfish Muslim on the basis of his religion nor can I fathom historical Muslims as being uninterested in the world considering their contribution of creating Algebra as we know it along with modern astronomy.
Ut supra, ita inferius
Uƚ ƨuqɿɒ, iƚɒ inʇɘɿiuƨ