I'd say Freedom Fox gives a good insight. We human beings are (for all practical purposes, e.g. at the scale of one -- or a hundred -- human lifetimes) essentially unchanging. Homo sapiens (the physical species) have been around at least 200,000 years and our close ancestors way before that. One implication, if one accepts that human traits are essentially static, is that at any given time there must be a certain percentage of sociopaths or other dysfunctionals within a population. What varies with time is how effectively (ruthlessly?) such abnormals are restrained or otherwise prevented from causing trouble.

None of the above is to say that human institutions cannot change. Of course circumstances, economies, cultures, religions, and so forth evolve with time and circumstance. A key failing of any idealist or reformer, though, is that with a wish that human being’s (or outer reality’s) inherent natures can be altered to taste, that Reality will bend to the command of the powerful merely because they have been designated “leader.”