I will preface this with the statement that my older two play team sports, both in HS and travel, and DH and I both played team sports. My eldest DD, DH and I have independently observed that the average IQ of teams that are more individual effort sports (swimming, wrestling, tennis, etc.) seems to be higher than the average IQ of true team sports (football, baseball, basketball, etc.)
This is not a slam against team sports; our family prefers the team sports. There are clearly individuals on certain teams that are very bright; my middle kid has a clearly gifted friend on her travel softball team. We have joked about getting a grant to study this, but I think there is likely a link with the gifted and control of the outcome (as others have mentioned). When my kids were younger, it did frustrate them that often the athletic kids didn't know where the play was (softball); the fielders hadn't thought about it before the batter came up to the plate. My kids are not that athletic, but they knew where the next play was and how each fielder should move.
