Small differences at the individual level are magnified at the social level.  For example, decades of social engineering to encourage women to take traditional male jobs has had little impact in the aggregate on job choice in Sweden.  This phenomenon exists despite the fact that at the individual level the difference between male and female mental abilities and personality proclivities is rather small.  

Humans are very sensitive to differences in personality and may tend to associate with people of similar proclivities.  They are also sensitive to differences in physiological traits, abilities and predispositions.  In any case and for whatever reasons people naturally form groups.   Groups will form subtle systems of social censure to maintain their identity, consciously or unconsciously.

Group dynamics are complex and chaotic, subject to outside influences and resistant to simple explanations.  It's why social engineering so often fails.  For social engineering to succeed it has to have complete control of every aspect of an individual's life.  The desire to be autonomous gets in the way.  Humans are particularly poorly suited for social control.  In some ways we are the most dependent species.  Slow development greatly extends the period of complete dependence but at the same time even from infancy humans have to have will.  We have to will ourselves to learn to stand and then walk.  We have to have the willpower to learn a vast array of essential skills.  Other animals have to have a similar "will" to live and learn but it is often more instinctual and always development is faster and in some ways less complex.  For humans the period of dependence never ends because of cultural complexity.  

The desire for autonomy and the need for cooperation define human existence.  Any practical political system will accommodate both.  Often by creating the illusion of autonomy.  Paradoxically people are easily convinced they are doing something of their own freewill when they are being manipulated.  Group identity, it turns out, is necessary for survival and is deeply instinctual.  At times it is possible to expand group identity such as in times of war or crisis.  The trick to practical political systems is to expand group identity to good times.  In the West group identity has been expanding to the point that "the brotherhood of man" is widely accepted.  At the same time group identity has splintered because we have had the luxury to believe ourselves self-sufficient.  Luxus it seems leads to delusion.  Hard times tend to dispel the illusion of independence and foster cooperation.  

The question is cooperation with whom.  The elites seem intent on artificially creating hard times to foster cooperation with them.  I'm not sure they even know what they are doing.  Group dynamics are so instinctual that they are not necessarily conscious.  The saying that leaders are born not created illustrates the point.  Some people simply want to have control from birth more than others.  The problem is that the same group dynamics that make cooperation possible also do not necessarily rely on merit.  The instinct for group identity also leads to subservience.  Correcting both of these flaws requires a carefully crafted social dynamic.  It will not happen naturally.  It's why only merit based civilizations are successful in the long run.