Biology uses .95 because it's virtually impossible to get better results than that. But it also means that 1 out of every 20 biology papers are completely wrong. And then you have papers based on those....
Physics wants a much greater degree of certainty, and since they have the ability to get it they insist on it.
You have to make sure to have results that are far far better than the number of experiments you are running. Otherwise you are virtually guaranteed to find some result that will seem right, but isn't.
(For example a 1 in a million occurrence (per person per day) [would] happen about 7000 times every day.)
That "completely wrong" is a bit harsh on biologists.
Firstly, it is a lot harder to repeat experiments in biology than in particle physics, as (as far as we know), all electrons are the same.
Secondly, biologists will, in general, not make bold claims. A paper "a possible link between X and Z" that works with p>0.95 and states that further research is needed is not a lie; the popular press makes it a lie by changing it to "OMG: X CAUSES Y".
I know it's a lot harder to repeat experiments in biology than in particle physics - I said that in my post.
Just because someone uses weasel words ("possible") doesn't change the end result: It's a wrong result.
I'm not blaming them - I understand better results are not possible. But it doesn't change the fact that a tremendous number of results are wrong.
It doesn't help that they often search for very subtle results. "It helps, but only a little." It also doesn't help that everyone responds differently to things. It makes the research very hard.
Anyway, I was just explaining why p95 is not accepted anywhere else except biology - biology just doesn't have any other choice. They don't prefer such low results.
Physics wants a much greater degree of certainty, and since they have the ability to get it they insist on it.
This http://xkcd.com/882/ sums it up pretty well.
You have to make sure to have results that are far far better than the number of experiments you are running. Otherwise you are virtually guaranteed to find some result that will seem right, but isn't.
(For example a 1 in a million occurrence (per person per day) [would] happen about 7000 times every day.)