Your Brain Lies To You

Your brain lies to you? At first glance, a preposterous statement. Why would anyone lie to themselves? But upon further inspection, the statement reveals more layers. It is not stating that we lie to ourselves, which is fairly common, but rather our brains are lying to us. It turns out, the lie is an innocent one, but can have significant effects nonetheless. As authors Sam Wang and Sandra Aamodt describe:

FALSE beliefs are everywhere. Eighteen percent of Americans think the sun revolves around the earth, one poll has found. Thus it seems slightly less egregious that, according to another poll, 10 percent of us think that Senator Barack Obama, a Christian, is instead a Muslim. The Obama campaign has created a Web site to dispel misinformation. But this effort may be more difficult than it seems, thanks to the quirky way in which our brains store memories — and mislead us along the way.

The brain does not simply gather and stockpile information as a computer’s hard drive does. Facts are stored first in the hippocampus, a structure deep in the brain about the size and shape of a fat man’s curled pinkie finger. But the information does not rest there. Every time we recall it, our brain writes it down again, and during this re-storage, it is also reprocessed. In time, the fact is gradually transferred to the cerebral cortex and is separated from the context in which it was originally learned. For example, you know that the capital of California is Sacramento, but you probably don’t remember how you learned it.

This phenomenon, known as source amnesia, can also lead people to forget whether a statement is true. Even when a lie is presented with a disclaimer, people often later remember it as true.

The implications of this phenomenon are disturbing. It helps explain why people often make very definitive statements, yet when questioned for further information, have a difficult time supplying the source or other related information. It is especially troublesome when a person has a high degree of confidence with a high degree of source amnesia. This pairing leads them to make statements with high certainty with little regard to how they came to be so certain. A vicious cycle develops: if the statement is questioned and found to be true, this result just increases their confidence / cockiness. However, if false, the person discounts the result as something "misremembered." I used to think of this as a kind of mental laziness, but now, perhaps I should be more compassionate and realize that the person is not lying to me; perhaps, instead, their brains are lying to them.

For more about the cognitive biases inherent to all of us, check out Nobel Laureate Daniel Kahneman's outstanding book Thinking, Fast and Slow: 

Updated 2015-12-13