New finding offers neurological support for Adam Smith's 'theories of morality'

April 9, 2012, New York University

The part of the brain we use when engaging in egalitarian behavior may also be linked to a larger sense of morality, researchers have found. Their conclusions, which offer scientific support for Adam Smith's theories of morality, are based on experimental research published in the latest issue of the Proceedings of the National Academy of Sciences.

The study, coming seven months after the start of the Occupy Wall Street Movement, which has been aimed at addressing , was conducted by researchers from: New York University's Wilf Family Department of Politics; the University of Toronto; the University of California, San Diego; the University of California, Davis; and the University of Nebraska, Lincoln.

Previous scholarship has established that two areas of the brain are active when we behave in an egalitarian manner—the ventromedial prefrontal cortex (vmPFC) and the insular cortex, which are two neurological regions previously shown to be related to social preferences such as altruism, reciprocity, fairness, and aversion to inequality. Less clear, however, is how these parts of the brain may also be connected to egalitarian behavior in a group setting.

To explore this possibility, the researchers conducted an experiment in which individuals played a game to gauge brain activity in decision-making. In the "random income game" participants in a group are randomly assigned a level of income and the group is assigned to one of three income distributions. Subjects are shown the income of all members of their group, including their own, on a computer screen. Individuals are then asked if they wish to pay a cost in order to increase or decrease the incomes of group members. Subjects are told they may keep the money they don't give away to the others shown on their screen, so there is a strong incentive not to part with any of the money already allocated to them. Nonetheless, the researchers found that the study's subjects frequently sought to reallocate resources so the money was more equally distributed among the group members.

During this period, the researchers gauged the subjects' neurological activity through functional magnetic resonance imaging (fMRI). As shown in previous studies, the researchers found significant activity in the brain's vmPFC and insular cortex.

But to get at a more detailed understanding of neurological activity during these behaviors, they also examined whether activations in these areas were associated with two additional measures of egalitarian preferences elicited outside of the fMRI. As part of a survey, subjects were asked their level of agreement or disagreement to six questions, which included: "Our society should do whatever is necessary to make sure that everyone has an equal opportunity to succeed" and "This country would be better off if we worried less about how equal people are." In addition, subjects completed a series of decision-making tasks asking them to split money with another anonymous person. The choices individuals make in this task are a measure of egalitarian behavior.

The researchers found that these two measures of egalitarian preferences were significantly associated with activations in the insular cortex, but not with the vmPFC.

This particular result is a potentially profound one as the insular cortex is also the part of the brain that processes the relationship of the individual with respect to her or his environment. In other words, egalitarian behavior may not exist in isolation, neurologically speaking, but, rather, be part of a larger process that stems from altruism and a sense of the larger social good.

Adam Smith, in The Theory of Moral Sentiments, expressed this perspective in his 18th-century essay.

"Adam Smith contended that moral sentiments like egalitarianism derived from a 'fellow-feeling' that would increase with our level of sympathy for others, predicting not merely aversion to inequity, but also our propensity to engage in egalitarian behaviors," the researchers wrote. "The evidence here supports such an interpretation—our results suggest that it is the brain mechanisms involved in experiencing the emotional and social states of self and others that appear to be driving egalitarian behaviors. This conclusion is consistent with a broader view of the as a neural substrate that processes the relationship of the individual with respect to his or her environment."

Explore further: How fair sanctions are orchestrated in the brain

Related Stories

How fair sanctions are orchestrated in the brain

October 6, 2011
Civilized human cohabitation requires us to respect elementary social norms. We guarantee compliance with these norms with our willingness to punish norm violations – often even at our own expense. This behavior goes ...

Sense of justice built into the brain

May 3, 2011
A new study from the Karolinska Institute and Stockholm School of Economics shows that the brain has built-in mechanisms that trigger an automatic reaction to someone who refuses to share. In the study publishing next week ...

Researchers determine region of the brain necessary for making decisions about economic value

May 18, 2011
Neuroeconomic research at the University of Pennsylvania has conclusively identified a part of the brain that is necessary for making everyday decisions about value. Previous functional magnetic imaging studies, during which ...

Recommended for you

New technique helps uncover changes in ALS neurons

June 22, 2018
Northwestern Medicine scientists have discovered that some neurons affected by amyotrophic lateral sclerosis (ALS) display hypo-excitability, using a new method to measure electrical activity in cells, according to a study ...

Broken shuttle may interfere with learning in major brain disorders

June 22, 2018
Unable to carry signals based on sights and sounds to the genes that record memories, a broken shuttle protein may hinder learning in patients with intellectual disability, schizophrenia, and autism.

Watching stem cells repair spinal cord in real time

June 22, 2018
Monash University researchers have restored movement and regenerated nerves using stem cells in zebra fish where the spinal cord is severely damaged.

Scientists discover fundamental rule of brain plasticity

June 21, 2018
Our brains are famously flexible, or "plastic," because neurons can do new things by forging new or stronger connections with other neurons. But if some connections strengthen, neuroscientists have reasoned, neurons must ...

Waking up is hard to do: Prefrontal cortex implicated in consciousness

June 21, 2018
Philosophers have pondered the nature of consciousness for thousands of years. In the 21st century, the debate over how the brain gives rise to our everyday experience continues to puzzle scientists. To help, researchers ...

Researchers find mechanism behind choosing alcohol over healthy rewards

June 21, 2018
A new study links molecular changes in the brain to behaviours that are central in addiction, such as choosing a drug over alternative rewards. The researchers have developed a method in which rats learn to get an alcohol ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.