How we really think. Not what you might expect.

Have you heard of the Trolley Problem paradox?  It is the best illustration of how human thinking is not rational like a computer.  That doesn’t mean it’s irrationally silly; it is actually a lot more complicated.  There are many pieces that evolved to do totally different things working in conjunction but not working together.  That’s what evolution does, compared to an engineering lab.

The reason the Trolley Problem is such a great illustration is that it is really simple to understand.  And it is very reliable – it has been tested over and over again with all different kinds of people and dozens of variations.  And there have been fMRI scan studies that clearly show what brain areas are driving each part of the decision.

Here is the basic problem.  A trolley is coming uncontrolled down the track.  If you don’t do anything, it will run into and kill 5 people instantly.  Or you can pull a track switch and move the trolley to a track that only has one person on it.  You will be saving the 5 people, but you will be signing the death sentence of the other one.  What do you do?

Then here is another problem.  Same basic premise – a trolley coming uncontrolled down the track, about to run into 5 people and kill them instantly.  There is another track that with nobody on it.  But you are on top of a bridge and the switch to shift the trolley is on the ground below.  You are not heavy enough to jump off the bridge and land on the switch to shift it.  So your only choice is either do nothing and let the five people one the track die, or to push a heavy guy standing next to you off the bridge, killing him, but saving the 5 people on the track.  What do you do? 

There are no right or wrong answers.  If you are a utilitarian (always choose the option that does the most good for the most people), then you would pull the switch and you would push the heavy guy to his death off the bridge.

If you don’t believe that you (or anyone) have the right to decide who should live and who should die, no matter how many people are involved, then you should not pull the switch and you should not push the heavy guy off the bridge. 

But what makes this a paradox is that most people pull the switch, but don’t push the heavy guy off the bridge (you probably made the same choices).  We seem to have one ethical value in one case and the other ethical value in the other case.  And when asked, we have a lot of trouble explaining the discrepancy.  This inconsistency broke all the models of early psychologists and early philosophers.  There were hypotheses, but nothing could ever be proven to a statistical probability.  It wasn’t until the invention of fMRI that we were able to learn what was happening.  And it is really fascinating !!!

So here is what we have learned.  In the first case, when you are pulling a switch, the cortex does most of the heavy lifting.  This is the rational part of the brain that thinks utilitarian.  The most good is to pull the switch.

But in the second case, the “ick” factor (composed of visceral feelings of guilt, sadness, and disgust) of personally contacting the person who is killed causes the amygdala and gyrus to override the cortex and make the opposite decision.  The amygdala and gyrus are evolutionarily older parts of the brain, so they win in any disagreement.  Not for logical reasons, for emotional reasons.

But people who have injuries in their amygdala/gyrus always make the utilitarian choice (push the heavy guy off the bridge).  They tend to be sociopaths because they don’t care about the person who is hurt as a result.  At least not emotionally.

And if we fatigue the cortex by making a person do a lot of thinking and reasoning, then they are more likely to make the less “icky” choice (they won’t even pull the switch). When rational thinking is tired, emotional thinking is happy to jump into the gap.

There are also personality differences.  People with more trait anger (not just temporarily angry, but more angry in general) make more utilitarian judgments (push the guy off the bridge).  On the other hand, trait empathy and trait disgust increase the “ick” feeling and make people less utilitarian.

Being temporarily happy (or really any positive emotion) decreases your ick feeling (guilt, sadness, and disgust) so you are more likely to be utilitarian. 

These results have been reproduced in a wide variety of decisions, not just trolleys.  The scenarios have gone with administering the death penalty, throwing a hand grenade, hitting someone by bowling a ball down the lane, and more.  Researchers have looked at old people, young people, ethical experts, ethical ignoramuses, males, females, different cultures, religions, etc.  There are many individual differences that change the exact percentages, but the main effect is generally the same.  More of each group pull the switch than don’t and more people don’t push the heavy guy off the bridge than do.  Except extreme groups like sociopaths.