People behave differently in different situations because they were raised differently. Had they been raised in the same social "ecology" as you have, they would tend to be much more like you. I've travelled and lived in several different countries that were quite different from that found in modern western societies, but the people were the same (albeit of different skin tone), except for cultural and sociological differences, which are clearly derived from the "nurture" side of the nature/nurture dichotomy.