The Believing Brain - Michael Shermer [73]
True: Most people have ten fingers and ten toes.
False: Eagles are common pets.
Uncertain: The Dow Jones Industrial Average rose 1.2 percent last Tuesday.
ETHICAL
True: It is bad to take pleasure at another’s suffering.
False: Children should have no rights until they can vote.
Uncertain: It is better to lie to a child than to an adult.
They made four important discoveries:
1. There were significant reaction time differences in evaluating statements. Responses to true (belief) statements were significantly shorter than responses to both false (disbelief) statements and uncertain statements, but there was no difference in reaction time detected between false (disbelief) statements and uncertain statements.
2. Contrasting the reaction to true (belief) statements and false (disbelief) statements yielded a spike in neural activity associated with belief in the ventromedial prefrontal cortex, an area of the brain associated with self-representation, decision making, and learning in the context of rewards.
3. Contrasting the reaction to false (disbelief) statements and true (belief) statements showed increased brain activity in the anterior insula, associated with responses to negative stimuli, pain perception, and disgust.
4. Contrasting the response to uncertainty statements with both true (belief) statements and false (disbelief) statements revealed elevated neural action in the anterior cingulate cortex—yes, the ACC that is involved in error detection and conflict resolution.
What do these results tell us about belief and the brain? “Several psychological studies appear to support [seventeenth-century Dutch philosopher Baruch] Spinoza’s conjecture that the mere comprehension of a statement entails the tacit acceptance of its being true, whereas disbelief requires a subsequent process of rejection,” Harris and his collaborators of the study reported. “Understanding a proposition may be analogous to perceiving an object in physical space: We seem to accept appearances as reality until they prove otherwise.” Thus, subjects assessed true statements as believable faster than they judged false statements as unbelievable or uncertain statements as undecidable. Further, because the brain appears to process false or uncertain statements in regions linked to pain and disgust, especially in judging tastes and odors, this study gives new meaning to the phrase that a claim has passed the “taste test” or the “smell test.”38 When you hear bullshit, you may know it by its smell.
As for the neural correlates of belief and skepticism, the ventromedial prefrontal cortex is instrumental in linking higher-order cognitive factual evaluations with lower-order emotional response associations, and it does so in evaluating all types of claims. Thus, the assessment of the ethical statements showed a similar pattern of neural activation as did the evaluation of the mathematical and factual statements. People with damage in this area have a difficult time feeling an emotional difference between good and bad decisions, and this is why they are susceptible to confabulation—mixing true and false memories and conflating reality with fantasy.
This research supports what I call Spinoza’s conjecture: belief comes quickly and naturally, skepticism is slow and unnatural, and most people have a low tolerance for ambiguity. The scientific principle that a claim is untrue unless proven otherwise runs counter to our natural tendency to accept as true that which we can comprehend quickly. Thus it is that we should reward skepticism and disbelief, and champion those willing to change their mind in the teeth of new evidence. Instead, most social institutions—most notably those in religion, politics, and economics—reward belief in the doctrines of the faith or party or ideology, punish those who challenge the authority of the leaders, and discourage uncertainty and especially skepticism.
The Brains of Believers and Nonbelievers
In a second fMRI study in search of the neural correlates of religious and nonreligious belief, Sam Harris and his UCLA