I found this with ds10 as well - he got a 22, which is in the 95th%-ile for 8th graders - and he has NO interest in science. They do almost no science in elementary school and it is not a topic about which he chooses to learn.
Same with my DS. He has not read any science book at home for a long time, but still got 25 last year and 24 this year. DS used to be a science kid and his teacher let Him lecture 1st graders about sun/moon/earth season relationship once. Now his interest has shifted totally from science (especially chemistry) into alchemy and mythology. They do have science in school, covers from force and motion to weathering and corrosion, all just barely introduction, nothing in depth according to DS.
