The first and second factors are of equal importance in the psyche and the same evolutionary tendencies which support survival also support culture (and all of the baggage that comes with it). This is because for a long period in our evolution the two were identical – culture was our memetic means of survival, as things like migratory flight routes were those of geese. What’s more, you can apply the same evolutionary rules and look for the same evolutionary patterns in culture as you can in biology. Some mass movements are actually excellent examples of Fisherian runaway applied to the propagation of ideas rather than genes.