One of my recurring themes here recently has been the ways our Old World primate brains make it difficult for us humans to understand many basic things, including probability and risk, geological time, contingency, extremly large- or small-scale events, and so forth.
Here's another one, an excellent psychology article about why we resist some scientific ideas more than others (via Pharyngula). Coincidentally, Harvard history of science professor Steven Shapin addresses a similar topic on the CBC Ideas podcast this week called "Testing Science" (MP3 file). Essentially, research shows that...
...even one year-olds possess a rich understanding of both the physical world (a "naive physics") and the social world (a "naive psychology"). [...] These intuitions give children a head start when it comes to understanding and learning about objects and people. But these intuitions also sometimes clash with scientific discoveries about the nature of the world, making certain scientific facts difficult to learn.
However, some concepts don't work that way, even when they are far from obvious. For example:
[The existence of germs and electricity] is generally assumed in day-to-day conversation and is not marked as uncertain; nobody says that they "believe in electricity." Hence even children and adults with little scientific background believe that these invisible entities really exist.
That's interesting, because our evidence for those things is pretty indirect, however pervasive: light switches and televisions and computers work, and washing your hands helps prevent infection. But most people have never seen a germ, never mind an electron. It would seem, purely objectively, that being able to look at rock strata in a highway cut, or watch the patterns of a coin flipped over and over, or observe the similarities and differences between chimpanzees and humans at the zoo, or hummingbirds and dragonflies in the garden, would make concepts like deep time and randomness and biological evolution easier to understand than electricity or germ theory.
Yet they are not. Our brains are remarkable things, and one of the most remarkable things about them is that we can, if we work at it as we grow up and throughout our lives, help ourselves get around our own cognitive limitations.