People are identical in the simplest ways --- and absolutely unique in the most complex ones.
We're totally alike at the level of fundamental forces, particles and fields, matter and energy ... made out of the same old standard building blocks ... protons and neutrons and electrons ... hydrogen, carbon, nitrogen, oxygen ... amino acids, peptides, and what-nots.
But mind and spirit, choice and experience, goal and path --- all different. It's something of a miracle that we can identify with others, sympathize with them, understand their motives, and communicate. (Maybe the most serious problems of crime and mental disability come from failures to do precisely that?)
Even at the seemingly-primitive level of cellular structure and metabolism, human individuals have already begun to diverge. A few decades ago I remember reading You Are Extraordinary, a general-audiences science book by biochemist Roger Williams which hammered home that very point. People react in wildly different ways to the very same foodstuffs, medications, stresses, and a host of other parameters.
Generalizations are risky; they need to be tested before they're believed. One size fits one, not all....
TopicScience - Datetag20020707