True the seasons in northern areas of the world are brutal. Thus scientists speculate that the need to work together to survive and planning required to farm and harvest and survive the brutal winters were perhaps the reasons why some groups appear to work harder than others.
That is very well true today. However in the past it was the sub-tropics which gave birth to all the great civilisations.
Egyptian, Roman, Greek, Indus, Persian, Mesopotamian, Mayan etc etc.