Would their children deviate from the norm in the other direction? What would we call this deviation? What characteristics would these children have? Would they be super-manipulators of others; or merely very charming?
Many other intensified characteristics might emerge out of assortative mating. How about very combative kids from parents who meet at the local dojo? Very bookish kids from parents who meet in graduate school? Very overweight children from parents who meet at Weight Watchers?
Practically every human trait can become a source of "birds of that particular feather flocking together." The possibilities are nearly endless. Think of your own examples.
