Is Morality a Result of Evolution? Study Shows Biological Roots of Moral Decisions

Primate Studies Show Biological "Morality," Recent Human Study Identifies Brain Area Involved

Two days after the New York Times Science section published a discussion earlier this week on apparent morality in primates and how it is reshaping some philosopher's views of their field, reports are discussing an article published Wednesday in the journal Nature in which the origin of a very similar effect in humans has been located, in the ventromedial prefrontal cortex (VMPC) of the brain.

The key difference between the primate discussion and the human experiments is the involvement of reason. The experiments involved subjects with varying states of health of their brains, with some having damage to the VMPC. In the experiments, subjects were presented with moral dilemmas which involved sacrificing one human life for the good of a number of others, such as pushing an individual off a train track to protect others, or killing an AIDS carrier who was planning to infect others.

Results of the experiments showed that subjects with damage to their VMPC were more likely to make choices than involved personally harming another human being, while those without damage to the VMPC refused or were reluctant. The experimenters characterized the difference as being the result of the VMPC's effect on compassion, shame and guilt.

Articles reporting the study from CBS News and the CBC in Canada noted that the subjects with specific damage in this area were not considered "immoral," but that, as in the New York Times article discussing primates, the effect of this part of the brain is where the origins of a moral instinct are found. Humans have developed beyond this instinctive behavior, and the Times article presents a case for the development of conscious moral systems such as religion based on the guidance of specific biological principles.