Why are people so scientifically illiterate?

We may be so scientifically illiterate in part because we're not as smart as we used to be.

I read an article recently--in Scientific American I think--summarizing paleontology research that discovered that our brain size has actually shrunk since we adopted agriculture around 10,000 years ago.

No one knows why exactly but my hypothesis is that we needed to be smarter as hunters & gatherers than we needed to be as farmers, and our large brain size kills women, so it's actually advantageous to have our brains as small as possible (and yet maintain the advantages a human brain confers).

It kills women because if it were any larger women wouldn't be able to walk using inverse brachiation (the way gibbons swing through trees, only upside down), but it can't be any smaller without losing brain capacity, since it has to be developed in utero (which is, incidentially, why marsupials are, as a group, as dumb as a box o' rocks).

Also, since the invention of birth control and women's rights (not really possible until we developed the technology needed to let them have fewer kids and not die in childbirth when they did), the smarter the parents, the fewer the children overall.

For one case in point, look at people's frequently simple-minded reactions to America's current economic situation.

It's not their fault, however. We didn't evolve to deal with such numerically complex problems, and a number of brain heuristics (detailed in several books by cognitive psychologists) actively skew our understanding, just to make things even worse.

For one example, take Baye's Law (named after the Reverend Bayes who first formulated it), whose mathematics I certainly don't understand, except that it lets scientists and engineers evaluate probability when two different probabilities apply. Instead of merging the probabilities proportionately, most people just throw one out, in a form of target fixation.

To really understand current economics and how national policy has to juggle issues like debt, unemployment, immigration, public health, city planning, military spending/technology/deployment, fisheries management, agricultural subsidies and more, most people go into what programmers might call a stack overflow condition. So they just focus on one or two things.

Currently the Republican mantra is debt--as if that's the most important problem we face (it's not, huge as it is--unemployment is bigger, and overpopulation/permanent natural resource degradation even worse). It's easy to describe in bumper sticker slogans, and it helps with the real agenda of the GOP's paymasters: to stop government regulation in every way possible, thus by focusing exclusively on debt/spending, they can defund government agencies that try to limit corporate rapacity. But that's not what's said. What's said tries to pretend that the federal government of the biggest economy in the history of the planet can be governed by the same principles and platitudes used by individual familes.

This really reflects not just the scientific illiteracy of the citizenry, but the inability of most citizens to admit that they don't understand it. Instead they turn to bumper sticker slogans used like tribal chants (and I have seen the Democrats go tribal on us as well--particularly with illegal immigration), because it's emasculating to admit that you don't, can't, and never will understand how the U.S. federal government manages its spending and priorities.

And the unwillingness to admit one is over one's head leads to mental shortcuts and not doing the hard work needed to get anything like a handle on the situation. It also leads to anti-intellectualism, since intellectuals/scientists keep saying complicated things. Better to deny such people's worth than to accept their conclusions, which are so unpalatable, and getting moreso every day.

Cassandra was cursed by a god to always predict correctly--and never to be believed.

Scientists can relate.

For example, I live in a condo complex with most buildings built over garages. It doesn't meet modern earthquake retrofit standards. Yet we just lost a vote to spend about $9K a unit to apply a proper retrofit.

The retrofit was opposed fiercely by a group of Russian immigrant families who believed it was all a scam--that our Board was in cahoots with the engineering firm. Some of them are even engineers (though not in structural engineering or earthquake retrofits). But they still opposed it. We're 10 miles from the Hayward Fault, which has generated a 6.8+ earthquake every 140 years or so for many thousands of years. It's now been 143 years since the last one.

And they voted in a bloc against the retrofit, and went door to door around the complex lobbying people, telling their conspiracy theories and being 100% certain that their layman's understanding of the probabilities and dangers was far more valid than a bunch structural engineers with decades of experience in earthquake retrofits.

So we're not just up against scientific illiteracy. We're up against the average person's belief that their know better than the experts.

Same goes for the insanity of parents preventing their kids from being vaccinated, even though the claim that it leads to autism is complete nonsense. And these parents--some with liberal arts BAs--will sit there and say, smugly, "I know what I know."

Only they don't. And they can't learn what they don't know because they deny that they don't know it.

People love science and scientists until they hear things they don't want to hear. Then we get self-confident dim bulbs like Governor Perry ascribing the 98% agreement of climate scientists on human-caused global warming to a vast international conspiracy of those scientists to get grant money.

And a majority of Americans appear to believe Perry...