We are a commune of inquiring, skeptical, politically centrist, capitalist, anglophile, traditionalist New England Yankee humans, humanoids, and animals with many interests beyond and above politics. Each of us has had a high-school education (or GED), but all had ADD so didn't pay attention very well, especially the dogs. Each one of us does "try my best to be just like I am," and none of us enjoys working for others, including for Maggie, from whom we receive neither a nickel nor a dime. Freedom from nags, cranks, government, do-gooders, control-freaks and idiots is all that we ask for.
I majored in Statistics in college (with a minor in English Lit), but my stats sophistication is a bit rusty now. But it's not so rusty that I do not raise my brow at any latest stats reported in medicine, or especially in Psychiatry - and especially genetic studies.
As Gene Expressions points out, it's partly because a p-value of 0.05, commonly used in such studies, is unrealistic for these things. It's straight out of How to Lie with Statistics, which is essential reading for all high school students.
For nearly all diseases, reproducible associations have small effect size and are only detectable when one has sample sizes in the thousands or tens of thousands (for many psychiatric phenotypes, even studies with these sample sizes don't seem to find much). The vast majority of candidate gene association studies had sample sizes in the low hundreds, and thus had essentially zero power to detect the true associations. By the argument above, in this situation the probability that a "significant" association is real approaches zero. The problem with candidate gene association studies is not that they were only targeting candidate genes, per se, but rather that they tended to have small sample sizes and were woefully underpowered to detect true associations.
While I find the field of behavioral genetics to be as fascinating as anything else in this world, I always read the latest gene-behavior studies with the highest skepticism. (Do I think real Bipolar Disorder has some provable genetic underpinning? Yes, I do, even though I do not think it has been adequately proven yet. But not much else genetic in Psychiatry has been adequately proven in my view. Schizophrenia maybe, IQ almost certainly, but possibly not homosexuality, or depression, or alcoholism.
The trick to getting papers published is to run your numbers so they show something. It's not rocket science if you know how to do it: just look at the climate studies. (Even Einstein fudged his math. He happened to turn out to be right, though, as far as we know today.) Science is about hypotheses, not Truth.
Excellent summary of what seems strongly genetic in the field at present, compared to what is still speculative.
When people complain that statistics lie, I tell them you can make numbers tell you the truth. You have to grab them by the throat, shake them, and ask "who are your friends?"
Assistant Village Idiot
" That's the great potential of private schools: you can demand performance. And he had a school to run, so could not be bothered with reading puerile or stolen papers. He wanted to know what you had to say for yourself, and he only gave one "A" per class."
You can't demand performance in public schools?
He had a school to run so couldn't be bothered reading papers. Period. That's a fine teacher.
He wanted to know what you had to say for yourself? Were you asked to synthesize new information and tell it to the class in one minute?
He gave only one 'A' per class. What happened when three students earned 'A's'? Did the two who did not get the 'A' feel failure and learn from it?
No paper and no exam. He just 'knew' by his shrewd observance.... Now off to soccer you scholars! I must muddle through my stupidity and send a slacker home.