Mr. Spock, the half-Vulcan first officer of the Starship Enterprise, claimed to lack human emotions. As a result, he was utterly rational in his decisions. I remember watching Star Trek as a kid and not being able to understand why Starfleet had chosen the somewhat impulsive James T. Kirk as captain over the more ‘logical’ choice.
Why wouldn’t you want the captain of the starship to make his decisions based on logic, without the irrational impulses foisted upon us by our human emotions? While the show attempted to answer this question by having Kirk make an illogical decision that turned out to save the ship, the crew, or possibly whatever world they happened to be visiting, it seems a bit of a stretch. Perhaps Kirk had a better grasp of human (alien?) nature, but about more concrete decisions of probability or logic, you’ve got to give the nod to Spock, right?
Not so fast. Maybe the Vulcans have a better system, but for humans, emotions seem to be key to rational decision making. Sounds bonkers, I know, but bear with me. As with much else in neuroscience, the key experiments take advantage of the plight of patients with particular brain injuries. The injuries, in this case, have to do with areas of the brain that either generates emotions or integrate them with factual information. Just as with lobotomy patients, a lot of these patients appear relatively normal and score well on intelligence tests, but suffer from severe problems nevertheless. One reasonably famous case involves a successful accountant who suffered a brain injury that removed his ability to experience emotions normally.
You will not be surprised to learn that his marriage subsequently collapsed. But what may seem a bit odd is that he also lost the ability to function as an accountant—a field in which emotion does not immediately seem critical—and wound up losing all of his money to a serious of scam artists in get-rich-quick schemes. In fact, this poor man lost the ability to make decisions generally. Upon returning to work after the injury, he was faced with the choice of whether to sign a document with a blue or black pen. This does not seem like a decision fraught with emotional consequences, but this man found himself unable to decide. You would think that he should have been able to rationally decide that this was a choice that simply didn’t matter and he could pick either one and not worry about it. But this proved impossible for him. Since either choice was equally reasonable, he was unable to choose between them and spent hours agonizing over which to use.
Now that was a bit of a particular case—a decision where there really isn’t a right or wrong answer and logic is only really necessary to tell you it isn’t worth bothering with. But what about a situation where Spock should really shine, where logic and probabilities are the keys, and there actually are right and wrong answers? Emotion still seems to be essential, strangely enough. Neuroscientists gave subjects a test called the gambling task. Most of the subjects were healthy. Still, some of them had an injury to a part of the brain, the ventromedial prefrontal cortex, which is critical for integrating factual information and emotional states. Simplifying things a bit, the subjects were allowed to pick cards from one of two decks, which had an amount of money on each card.
In the first deck, 9 out of 10 cards gave +$100, but the tenth was a loss, such that on average, every ten cards had an expected loss of $250. In the second, 9 out of 10 gave $50, and the tenth was a loss averaging $200, for an expected gain of $250 every ten cards. Most participants gradually started choosing more and more from the ‘good’ deck and less from the ‘bad’ deck. Eventually, the subjects were able to reason out the fact that the $50 deck was the better choice and explain their reasoning to the scientists. This was true of both the unimpaired and impaired subjects.
The unimpaired subjects, however, did something interesting. Well, before they consciously understood which was the better deck and before they even believed they had a hunch as to which was better, they were choosing the $50 deck more often. And their physical responses—perspiration, heart rate, etc.—were already anticipating a negative outcome when they picked from the bad deck. The impaired subjects did not do this. They failed to have any anticipatory response at all, which isn’t all that odd given their particular injuries. It isn’t even all that strange that they did not start choosing the good deck before they consciously understood what was going on. After all, they didn’t have the emotional guide that made them more anxious when they were picking from the bad deck than the good deck. The really odd thing is what happened after they had figured out what was going on with the two decks. Even though they knew the $50 deck was better, and could lucidly explain why they persisted in picking more from the $100 deck than the $50 deck. It’s not entirely clear what was going on. Still, scientists believe that without the anticipatory emotional response making the $100 deck feel bad, the subjects were unable to resist the lure of the higher amount. It is apparently not so much our rational analysis of the payoffs but the ability to imagine the emotional state we will be in if we hit the big negative card that causes us to choose $50 instead of $100.
So much for the power of rational thought. It seems that the best we humans can hope for from our logical, rational faculties is that they enable us to have the anticipatory emotional responses which guide us to do the right thing. Sure our emotions can be manipulated—the reason why the fresh fruit and vegetables are near the entrance of the supermarket is because the supermarkets know that we’ll be more receptive to buying junk food if we have already had the warm virtuous feeling that comes from buying the wholesome stuff—but without them we wouldn’t be rational, responsible Spocks. We’d be isolated, terminally indecisive, and somehow willing to fall for any get-rich-quick scheme that crosses our paths. Give me irrational fat and happy any old day, so excuse me while I go eat some of those Oreos that somehow wound up in my grocery cart yesterday.