Here's a fascinating discussion of the way we human beings make judgments and decisions. It's especially useful when thinking about how many of us badly miscalculated Iraq's pre-war WMDs and even how to grapple with the costs and risks of acting now to prevent or ameliorate climate change. Humans like certainty. In areas where we know least we are most intent on it. An experiment unpacks how:
Camerer's experiment revolved around a decision making game known as the Ellsberg paradox. Camerer imaged the brains of people while they placed bets on whether the next card drawn from a deck of twenty cards would be red or black. At first, the players were told how many red cards and black cards were in the deck, so that they could calculate the probability of the next card being a certain color. The next gamble was trickier: subjects were only told the total number of cards in the deck. They had no idea how many red or black cards the deck contained.
The first gamble corresponds to the theoretical ideal of economics: investors face a set of known risks, and are able to make a decision based upon a few simple mathematical calculations. We know what we don't know, and can easily compensate for our uncertainty. As expected, this wager led to the "rational" parts of the brain becoming active, as subjects computed the odds. Unfortunately, this isn't how the real world works. In reality, our gambles are clouded by ignorance and ambiguity; we know something about what might happen, but not very much. (For example, it's now clear just how little we actually knew about Iraq pre-invasion.) When Camerer played this more realistic gambling game, the subjects' brains reacted very differently. With less information to go on, the players exhibited substantially more activity in the amygdala and in the orbitofrontal cortex, which is believed to modulate activity in the amygdala. In other words, we filled in the gaps of our knowledge with fear. This fear creates our bias for certainty, since we always try to minimize our feelings of fear. As a result, we pretend that we have better intelligence about Iraqi WMD than we actually do; we selectively interpret the facts until the uncertainty is removed.
My italics. I think the relationship between fear and the need for certainty is strong. It certainly clouded my judgment after 9/11 and before the Iraq war. And I think extreme fear in the face of globalizing modernity is the deep engine for the rise of religious fundamentalism right now - both Christian and Muslim. In fact, that's the key argument of my book. And the antidote to such fear? A combination of reason, doubt - and existential nerve.