A pharmacologist at Oxford, Susan Greenfield, is putting forward a theory that computer games cause dementia in children. The theory itself doesn’t really concern me, but I do notice that often when someone comes out with a theory like this, people tend to be pretty dismissive — you hear things like “How can you possibly think that?” Well, every fact we know about the world had to be thought by someone first, and just because it sounds ridiculous or even offensive doesn’t necessarily make it wrong.

However, any theory, especially a controversial one, does need to be verified or rejected with plenty of evidence, and that’s where publication comes in. At the Bad Science blog post linked above, Dr. Goldacre makes a good point

Science has authority, not because of white coats, or titles, but because of precision and transparency: you explain your theory, set out your evidence, and reference the studies that support your case. Other scientists can then read it, see if you’ve fairly represented the evidence; and decide whether the methods of the papers you’ve cited really do produce results that meaningfully support your hypothesis.

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In this regard, I don’t mean peer review, the “least-worst” system settled on for deciding whether a paper is worth publishing, where other academics decide if it’s accurate, novel, and so on. This is often represented as some kind of policing system for truth, but in reality, some dreadful nonsense gets published, and mercifully so: shaky material of some small value can be published into the buyer-beware professional literature of academic science; then the academic readers of this literature, who are trained to critically appraise a scientific case, can make their own judgement.

The key point is that a valid theory should stand on its own. You should be able to just write it up and set it out there for other people to review. Sometimes people will try to gain support for their pet theories by advertising to the public, or engaging their opponents in a debate, which is fine, but it’s easy enough for the merits (or lack thereof) of the theory to get obscured by the discussion. Having a written description avoids all that. So be wary of any claim whose author is reluctant to write it up and publish it.