Watching rather diverse outcomes between even identical twins, much less non-identical siblings, suggests that the genetic component is a rather strong contributor. While equality before the law is essential, any expectations of equal achievement are bound to be frustrated. Further, even defining “equal achievement” is impossible: is a welder better or worse off than a bus driver or a music teacher? Is a person raising one well adjusted kid better off than another raising three less well adjusted kids? Are two identical twins in identical jobs and relationships truly equal if one of them is happy and the other isn’t? And, should perfect equality of outcome become possible, how would such a heterogeneous population survive any changes in the environment?
Equality of opportunity is likewise a fiction. If all are offered math instruction and only some succeed at first, then all kinds of science classes are beyond the grasp of the laggards. The same is true with artistic and communication ability: further opportunities are neither tenable nor hold much interest for the unequipped. Remedial courses are an option, but they take from the finite time available for learning skills of greater interest. Lastly, nobody should be obligated to teach a student whose fondest dream is harming the teacher or the other students rather than absorbing the lessons.