lifefin 72

Stuff I couldn’t stuff into thebook,
but that I think is pretty interesting …
(mostly on the brain science around Life)

One portion of the brain is tasked with keeping us alive. The amygdala is a small, almond-shaped (the word amygdala is drawn from the Latin word almond) collection of three nuclei at the base of the brain. The amygdala governs our emotions and our “fight or flight” responses. The pathway from the amygdala to the prefrontal cortex (which governs our actions) has been described as a one-way superhighway. There is a strong one-way connection to ensure that when we fear for our lives, we take immediate action. The pathway back from our decision-making center in the prefrontal cortex to the amygdala has been described as a series of winding little country roads. Our decisions—particularly life and death decisions— are not ours to make. The brain’s structure makes it very difficult for us to regulate emotions based on what our logic tells us we should do. And you can’t short circuit the connection.

Consequently, we have a bias to notice and pay attention to things that may harm us. In a 1988 study in the Journal of Personality and Social Psychology, Hansen and Hansen found that we naturally pick angry faces out of a crowd much more quickly than happy faces. Sure, we’d all love to believe the world is a happy place, but our amygdala makes sure that any potential threat is dealt with first. Our brain makes sure that we are protected first … then and only then, can we begin to enjoy.

Throw mama from the bridge

Joshua Greene, an Assistant Professor of Psychology at Harvard, spent his early career investigating such trade-offs—most famously by using the switch versus the footbridge experiment. In this research a runaway trolley is hurtling toward five people tied to a track, but there is a switch to divert the trolley to a track with only one person tied to the track. Most people would choose to divert the train and sacrifice one person to save the lives of five.

But in the next scenario, the same trolley is hurdling toward the five people but there is no switch this time. Instead you are standing on a footbridge over the track with a stranger. The question is: would you push this person in front of the trolley—definitely stopping the train—to save the five people further down the track? To this, most people say, “No.” (

The utilitarian part of the brain knows that it is better to save five and kill one, but in the footbridge scenario, the emotional part of normal brains kicks in and we abhor the “action” of pushing another person to their death. However, patients with damage to their ventromedial cortex are just as likely to throw the switch, as they are to throw a stranger from the bridge.

Damage to the prefrontal cortex increases utilitarian moral judgments. Something about that part of the brain is what makes us not want to harm other people—it is the part of the brain where we decide that not only our own Life, but the lives of other people are really important and that we shouldn’t harm them (Koenigs, M. et al., Nature, v. 446, 2007).

And in this, we are quite different from other animals. Most species on earth are out to protect only themselves. Sometimes mothers will instinctively protect their young, but once they are grown, it is all for one and none for all. But, as humans we will throw ourselves in the path of an oncoming car to protect another. And, even more oddly, we’ll risk harm and death to protect other species. We punish other humans if they are cruel to or kill animals that we deem worth protecting. We are truly good folk!

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