Individual, the conglomerate entity, has differences rather than similarities with each other. But every individual is confined to the helplessness of generalized perception. In other words, it is a human deficiency that human beings can't afford unwanted energy expenditure as part of their increasing utility demands that leads them to generalize things to a certain extent on the basis of some perceivable common threads running through them. These threads can be observed as the major factors identified similar in the things around. This 'weakness' of identifying similarities can be a boon to the human civilization.
Read the full article on SOCYBRETY.