I stumbled on an interesting article over at New Scientist that asks the question where does your sense of right and wrong come from? (subscription required) In other words, are moral decisions based on emotion or logic? As it turns out, the answer is both.
The article lists a few scenarios requiring moral judgment. For instance,
A TROLLEY train comes hurtling down the line, out of control. It is heading towards five people who are stuck on the track. If you do nothing they face certain death. But you have a choice: with the flick of a switch, you can divert the trolley down another line – a line on which only one person is stuck. What do you do? Perhaps, like most people, you believe that it is right to minimize the carnage, so you do the rational thing and flick that switch.
But what if the situation was slightly different? This time you are standing on a footbridge overlooking the track. The trolley is coming. The five people are still stuck, but there’s no switch, no alternative route. All you’ve got is a hefty guy standing in front of you. If you push him onto the line, his bulk will be enough to stop the runaway trolley. You could sacrifice his life to save the others – one for five, the same as before. What do you do now?
In scenario two, very few people will actually push someone to their death for the sake of the greater good. It just feels wrong to them.
Scientists are curious to know why – and Joshua Greene, a philosopher and cognitive scientist from Princeton University has used brain imaging techniques to understand the difference.
Their functional magnetic resonance imaging studies suggest that the different situations elicit different brain responses. Given the choice to flick a switch, areas towards the front of the brain, associated with “executive” decision-making functions, become active, much as they do in any cost-benefit analysis. By contrast, when deciding whether or not to push a man to his death there appears to be a lot of activity in brain areas associated with rapid emotional responses. Throwing someone to their death is the sort of up-close-and-personal moral violation that the brain could well have evolved tools to deal with, explains Greene. By contrast, novel, abstract problems such as flicking a switch need a more logical analysis.
As well as using different brain areas in the footbridge scenario, people also take longer to make a decision – and longer still if they decide to push the man. There is evidence of an internal conflict as they consider taking a morally unpalatable action to promote the greater good. This shows up as increased activity in the anterior cingulate cortex, an area of the brain known to be activated in cognitive conflict. Following this, areas associated with cognitive control and the suppression of emotional responses also light up – with activity particularly marked in people who choose to push.
Greene believes this activity reflects the cognitive effort required to overcome the emotional aversion to harming others.
So how do emotion and logic play roles in our morals? In many cases, people go with their gut instinct without relying on rational thinking. Studies by Jonathan Haidt from the University of Virginia in Charlottesville support the notion that emotions like disgust play a big role in what we find morally acceptable.
For example, they presented people with a scenario in which a brother and sister, holidaying in a cabin, decide to experiment by having sex with each other. Both use contraception, so there is no chance of producing a child that would pay the genetic price of inbreeding. They never repeat the experiment and continue their lives normally, with neither suffering any adverse psychological effects.
If you recoil at this, you are not alone. But many people go further – they condemn the act as morally wrong. When pushed to explain why, they often end up saying something like: “I don’t know, I can’t explain it, I just know it’s wrong.” According to Haidt, this “moral dumbfounding” suggests that moral reasoning occurs after moral decisions have been made, and is really about publicly justifying moral judgements already reached though intuitive, emotional processes. “The reasoning process is more like a lawyer defending a client than a judge or scientist seeking the truth,” he says.
Yet, we also use rational thinking when social norms change. At one time, slavery, interracial marriage and unequal rights were considered the norm. Now, the hot button issues people are fighting over are abortion and gay marriage. What will tomorrow bring?
And on a day to day level, we rationalize things all the time. What’s more important – work or your kid’s soccer game? Donating to charity or buying that new gadget you’ve had your eye on? Giving money to the homeless beggar or avoiding eye contact?
Still, like the article points out, it’s fascinating how closely disgust and morality go together – and how much our gut emotional reaction can be easily influenced.