Brain Injury Changes Moral Judgment

As a companion piece to yesterday’s post, have a look at this article from today’s New York Times. It begins:

Damage to an area near the center of the brain, several inches behind the eyes, transforms the way people make moral judgments in life-or-death situations, scientists are reporting. In a new study, people with this rare injury expressed increased willingness to kill or harm another person if doing so would save others’ lives.

The findings are the most direct evidence to date that humans’ native revulsion for hurting others relies on a part of neural anatomy, one that likely evolved before the brain regions responsible for analysis and planning.

The researchers emphasize that the study was small and that the moral decisions were hypothetical; the results cannot predict how people with or without brain injuries will act in real life-or-death situations. Yet the findings, appearing Thursday in the journal Nature, confirm the central role of the damaged region — the ventromedial prefrontal cortex, which is thought to generate social emotions, like compassion.

The article goes on to describe how this study is consistent with other results showing that a capacity for moral thinking is hardwired into the brain. This is highly significant. The existence of a moral sense in humans has long been cited by theists as evidence for the existence of God. C.S. Lewis famously made this the centerpiece of his argument in Mere Christianity. But it is becoming undeniable that specific regions of the brain are responsible for our capacity for moral reasoning, and that our moral intuitions are merely more highly developed forms of things already present in modern apes.

In this recent post I discussed work regarding the evolution of religion. I argued that the idea that a propensity for religious belief is something that emerged via evolution is easier for atheists to assimilate than it is for theists. I think the same can be said for the findings described here.

Sure, a physical structure in the brain that provides our capacity for moral reasoning might be a gift from God. The fact remains, however, that our brain can do a great many things and most of those things are not cited as evidence for the existence of God. If our moral sense results from physical structures in the brain that are themselves the product of evolution, it becomes hard to argue that our awarenes of moral universals is evidence for a universal lawgiver.


  1. #1 Blake Stacey, OM
    March 21, 2007


  2. #2 Blake Stacey, OM
    March 21, 2007

    The NYT piece mentions that the research was published in Nature, so here’s a direct link to Kerri Smith’s “To kill one, or watch many die?” in today’s Nature News.

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