In my continuing ramblings about what science is versus what it ought to be, I thought I’d touch briefly on a topic that is well understood in the community but doesn’t seem understood outside of it, that is the question of how a scientific hypothesis becomes scientific dogma.  I don’t mean dogma in a negative sense, in my area of science a dogma is simply something that is without question because all the evidence points to it being true.  The “central dogma” of biology for example is that DNA is where genetic information is stored, RNA is the messenger of information, and protein executes the functions that are demanded by the information.  DNA->RNA->proteins is a dogma taught to every aspiring biologist and bored high school student, and it underpins every piece of modern biology we do.

But dogmas don’t become dogmas out of nothing, there must be a mountain of evidence in their favor, and additionally there is usually a prior dogma or competing hypothesis that they must replace.  This last bit is important, it has often been said that you can’t reason someone out of a position they did not reason themselves into, but equally true is that you often can’t reason them out of something that they did reason themselves into either.  People just don’t like changing their mind.  And so when a new hypothesis comes along challenging an old dogma, scientists don’t just accept it straight away, instead they will demand more and more evidence for it while continuing to cling to what they learned in the old dogma.  Science advances not through persuasion but through retirement as these heralds of the old dogma retire and get replaced by people who learned the new hypothesis.  And those people in turn accept the hypothesis fully and turn it into a dogma to be taught to students who don’t yet have the full knowledge base yet to understand why something is true but who can be taught that it is true, hence dogma.

During the upwelling of a new hypothesis though, holy wars can happen.  I don’t mean fighting and purges, I instead mean the kind of holy wars that nerds engage in, the kind of demeaning of those on the “other side” in the sense of “oh you have a Gamecube instead of a PC? I should have known you were a console peasant.”  These holy wars infect science too, scientists try to be nice for professionalism of course but they will spend enormous efforts undercutting each other’s theories and at times even undercutting each other’s professional trajectories in their bid to garner support for their own theory.  This may seem needlessly cruel but there is an element of rational self-interest, if you think your theory is true then supporting the truth against the false is good praxis, and in more base terms there is only so much funding to go around so ensuring that your dogma or theory is held in higher esteem will ensure your side is the one receiving the lion’s share of scientific funding.I know this all sounds like pointless waffle, but I was specifically reminded of this when I recently saw a few talks on Alzheimer’s disease.  The holy war over Alzheimer’s can’t be summed up in a short blog post, but some people think Alzheimer’s is caused by a protein called “A-beta” and some think it is caused by one called “tau”.  A few hold a compromise position that perhaps both proteins are necessary but most of the scientists I’ve seen presenting talks hold to one side or the other, and both sides are competing to become the new dogma.  For the most part these two sides talk past each other, if you think that A-beta is the cause of Alzheimer’s disease then there isn’t as much a point in researching tau, and vice versa.  But occasionally you’ll find both sides present at a symposium and there they will feel the need to defend themselves to the audience and slyly denigrate the opposing position.  Never to the level of insults (in public) but instead to the level of “I respectfully suggest that those other scientists have grossly misunderstood the evidence.”  Which is a very kind way of saying fuck you.