The double holdback (start kindergarten late, than repeat a grade at some point later) is common among many wealthy families. Middle class and lower families have financial pressures making sure they send their kids to kindergarten on time, and can't afford the extra year of private school tuition later on. Forget about lax - being older gives them an edge academically and socially, which helps them get into the better schools, etc. Than once they graduate from a top college, this fact justifies the nepotism that gets them a plum job.