Psycho- social Evolution

What is meant by psycho- social evolution? From the living cell up to man, biological evolution was motivated by organic satisfactions, numerical increase, and organic survival. But with the appearance of man, these become, says modern biology, secondary and not primary; the primary motivation becomes fulfillment: and evolution itself becomes, at the stage of man, conscious and deliberate and goal- oriented, unlike the blind processes at the pre- human stages. This revolutionary change is the result of the fully developed cerebral system in man, in virtue of which the evolutionary process itself undergoes a revolutionary change; what was organic evolution becomes psycho- social evolution. Grow your own gnome