> Interesting. I couldn’t initially think of any plausible explanation for why height would cause intelligence.

Science is no longer interested in explanations, correlation is enough to assume causal "contribution."

I honestly think that taller people could be smarter simply because they're more often looking down at the person they're asking for an explanation from. It's a lot easier to ignore or brush off someone who is looking up at you.

edit: I also had a little sister (14 years younger) who was very tall as a child, although by adulthood she fell back closer to the norm (she's only about 5'10" now.) It was amusing to our family how carefully strangers explained concepts to her that were well beyond her age level to understand; because her height made her look older, it also made her look stupid for her age, and invited special attention from people who didn't realize how young she was. We use height as a proxy for age, and put pressure on taller people to be smarter earlier.