The NYTimes has started a blog series on this topic, titled: "The Anosognosic's Dilemma: Something's Wrong but You'll Never Know What It Is (Part 1): A ludicrously botched bank robbery leads to the question, Can you be too incompetent to understand just how incompetent you are?"
350 comments so far--many from obviously intelligent people--yet not one (nor the blog authors) seem to realize the four biological facts that are crucial to this issue:
1. evolution is totally blind. It's a mechanism, not a purpose.
2. evolution does not select for the fittest individual. It selects for the most reproductively successful GENE POOL.
3. we evolved to succeed as hunter/gatherers in the Kenyan highlands, with minor adaptations to other hunting-gathering environments.
On the macro level, however, we stopped evolving for the most part once we learned how to evolve our environment to suit ourselves, instead of vice-versa.
So we're still optimized to be hunter/gatherers living in tribes of a few dozen people (i.e. no more than can find food in one place in one day). Biologically speaking, you could say that modern society blindsides our inner nomadic forager every day.
4. the human race has a high degree of genetic plasticity--that is, we breed every whichway, like dogs, and unlike cats. Meaning that nature keeps trying stuff.
This probably stems from our evolving during unstable circumstances, forcing us to be highly adaptable, not just as individuals, but, evolutionarily speaking, not \"knowing\" just what's going to work. In highly stable circumstances evolution produces highly specialized life forms. Think koalas, which only eat one thing and have the brains of a turnip.
So--sociobiologically, the bell-shaped intelligence curve stems from the fact that (1) most people have enough intelligence to learn what to eat, how to acquire stuff to eat, how to avoid what wants to eat or kill you, in a particular environment; and (2) a tribe can't have all chiefs and no indians.
But this blog wasn't about the prevalence of stupidity. Nor is it really about ignorance of ignorance. It's about unwarranted confidence.
To understand why we have that, consider this situation: it's 100,000 years ago. Your band of a few dozen people is walking through the veldt. You don't even know about bows and arrows--all you have is rocks and clubs. Maybe some spears--sharpened sticks, really. Now here comes a lion.
If everyone were completely rational and only lived for self-advantage, the alpha male would toss the lion babies and children until it was satiated and went away. Or everyone would try to hide behind everyone else, with the strongest pushing the weakest in front of them--with similar results.
But they weren't rational. The alpha male would be full of rage at the lion trying to take his possessions--the other tribe members--and he'd also be full of self-sacrificing protective urges for his own females and his children. And he and his beta males would stand shoulder to shoulder confronting the lion with their rocks and clubs etc.
And within each of they psyches they'd figure the lion may get the guy beside me but he won't get me. I'll succeed. I'll pull this off. Because...well, because I'm ME.
That's where this all comes from, and it's found to varying degrees in most of us, both smart and stupid. It's just more easily seen in the hapless American Idol loo-hooser contestants. But the BP CEO wanting his life back or Bernie Madoff have this same trait.
Those of us who are somewhat self-aware can realize the power of this build-in heuristic in our minds, and try to compensate for it. But it's really, really hard.
Worth trying, though. I wish everyone the best of luck in trying to perceive reality accurately in the midst of the hormonal hurricane that is the human mind.
And of course, just because you may understand the origins of some aspect of human behavior--such as overconfidence--doesn't free you from its grip. It just makes you more morally culpable. "Responsibility" factors into response-ability, after all.
So those who see sociobiology as excuse-making need not fear. It's anything but.
OTOH if you think understanding how we came to be what we are is irrelevant--well, the best way to be controlled by the adaptive heuristics buried in our DNA is to deny their existence. Plus, one of the commonest forms of overconfidence is the persistent human belief that we invented ourselves, free of any kind influence by society, family, language, propaganda...and biological heritage.