As the younger who skipped, I did not know the impact on my older brother until we were adults. It affected him greatly, self esteem etc. He set the bar lower for himself, lower than he had to. But as I said, it was long after that I realized. Nothing that would be noticeable at the time.
That happens among siblings all the time, regardless of whether there was a skip involved. Siblings often seek to differentiate themselves with some sort of specialty in order to carve out an identity and earn parental approval. Once one of the kids locks down the "smart one" role, the others tend to look around for something else.
This tends to play out in other domains, too, as kids may become "the athlete," "the funny one," "the popular one," "the leader," "the artist/musician/actor," etc. A sibling with a similar talent may hold themselves back/out of such activities simply because they think they'll never be as good as their sibling, so what's the point?
