I found this analysis quite interesting as an example of the tough decision-making parents face.
Sports participation in childhood brings a lot of enormous benefits – cardiovascular fitness which can really increase adult health, for example, and lots of skills related to cooperative behavior and social interaction. Also, organized sports are a path for a kid from a less-advantaged home to achieve a college education and a big step up on the socioeconomic ladder.
And, the risk of lifelong bad outcomes that are large enough to measure appears very small. So, why not let your kid play – or even encourage them to?
On the other hand… there’s plenty of sports out there which offer the exact same benefits without risking lifelong brain damage. As a hypothetical parent, I’d sure be much happier if my kid picked one of those.
Refining our understanding of the risks will be difficult, because kids (and people in general) have such unknowable potential. If your kid plays sports and comes out a pretty average adult – who is to say s/he wouldn’t have come out a genius without the sports?
And in a world where lots of parents choose to let their kids (and everyone else) risk horrible infectious diseases because they heard vague and now-debunked concerns about immunizations… the only guaranteed thing is that most parents won’t make this call on a rational basis anyway.