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Emory brain imaging studies reveal biological basis for human cooperation
EurekAlert ^ | 17 July, 2002 | Kathy Ovnic

Posted on 07/19/2002 4:21:00 PM PDT by Nebullis

Functional MRI scans have revealed a "biologically embedded" basis for altruistic behavior, with several characteristic regions of the brain being activated when players of a game called "Prisoner's Dilemma" decide to trust each other and cooperate, rather than betray each other for immediate gain, say researchers from Emory University. They report on their study in the July 18 issue of the journal Neuron, published by Cell Press.

For many years, evolutionary biologists, behaviorists, economists and political scientists have attempted to understand why cooperation exists between human beings, even though that cooperation may not result in a direct or immediate reward. This unselfish behavior called "altruism" is almost uniquely a human trait.

Up until now, almost all brain imaging experiments that have studied the social brain have done so by exposing subjects to static 2-D images inside the scanner. "This study represents an attempt to learn about the social brain by scanning people as they are engaged in a true social interaction," said James K. Rilling, Ph.D., principal investigator in the Emory study, who is currently serving a postdoctoral fellowship at Princeton University. In the Fall of 2003, Dr. Rilling will return to Emory as a faculty member with a joint appointment in the Center for Behavioral Neuroscience (CBN) at Emory University School of Medicine and the Emory University Department of Anthroplogy.

In two separate experiments, the researchers used fMRI to scan the brains of 36 women while they played the "Prisoner's Dilemma Game," a decades-old model for cooperation based on reciprocal altruism. Two players independently chose to either cooperate with each other or not (defect), and each was awarded a sum of money that depended upon the interaction of both players' choices in that round.

In the first experiment, 19 subjects were scanned in four game sessions designed to observe neural function during cooperation and non-cooperation during both human interactions (social) and interactions with a computer (non-social). The results of the first experiment revealed different patterns of neural activation depending on whether the playing partner was identified as a human or a computer. In the second experiment, 17 subjects were scanned during three game sessions, focusing specifically on human interaction.

Mutual cooperation was the most common outcome in games played with presumed human partners in both experiments, even though a player was maximally rewarded for defecting when the other player cooperated. During the mutually cooperative social interactions, activation was noted in those areas of the brain that are linked to reward processing: the nucleus accumbens, the caudate nucleus, ventromedial frontal/orbitofrontal cortex and rostral anterior cingulate cortex.

"Our study shows, for the first time, that social cooperation is intrinsically rewarding to the human brain, even in the face of pressures to the contrary, " said Gregory S. Berns, M.D., Ph.D., co-investigator and associate professor of psychiatry in the Emory University School of Medicine Department of Psychiatry and Behavioral Sciences and member of the CBN. "It suggests that the altruistic drive to cooperate is biologically embedded-- either genetically programmed or acquired through socialization during childhood and adolescence."

"Reciprocal altruism activates a reward circuit, and this activation may often be sufficiently reinforcing to override subsequent temptations to accept but not reciprocate altruism. This may be what motivates us to persist with cooperative social interactions and reap the benefits of sustained mutual cooperation," said Dr. Rilling.

"The combination of game behavior and functional brain imaging also provides a unique paradigm to explore the neural basis of social behavioral disorders such as autism, drug addiction and sociopathy, that are characterized by deficits in social reciprocity, impulse regulation, or social reward processing," adds Clint Kilts, Ph.D., co-investigator and associate professor of psychiatry at Emory. "It defines the most complex form of the human genesis of a social bond. It may help us define why wars are fought and loves are lost."

###

The study was sponsored by the Markey Center for Neurological Sciences Fellowship, National Institute on Drug Abuse (NIDA), National Institutes of Mental Health (NIMH) and National Alliance for Research on Schizophrenia and Depression (NARSAD). Other Emory researchers involved in the study were David A. Gutman, Thorsten R. Zeh, and Giuseppe Pagnoni, Ph.D.


TOPICS: Culture/Society; Miscellaneous; News/Current Events; Philosophy
KEYWORDS: altruism
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To: tpaine
At #30 you claimed 'reliance on self-interest' to be a flaw in a libertarian society.

It's a failure of the system, for not taking into account human nature, not a failure of libertarians. Or, I suppose that insofar as it's a human failure, it's a failure of design.

Not so;
--- In a constitutional republic, which is the prefered
government form of libertarians.
--- Wouldn't you agree?

That depends on the implementation. It seems pretty clear to me that a totally non-coercive, completely voluntary system is going to be a pretty risky proposition. At a minimum, there will need to be some element of mandatory contribution to something like national defense. Take cases like that into account, and I think a society that is about 98% built on libertarian principles is entirely workable. I just don't think you can go all the way 100% libertarian, as a practical matter. Not that there's anything wrong with a society that's more libertarian than it is now, to be sure.

I've seen no libertarian system that so proposes. - Have you?

Sure. a full-blown anarcho-capitalist system always relies on the common good to be improved by people acting in their own rational self-interest. Sometimes, though, the best, most rational choice for individuals leads to a breakdown of the common good, as in the case of national defense, and perhaps one or two other things. I don't think that these cases of negative externalities are nearly as common as most people believe, but I do think it's hard to avoid admitting that they do exist in a few cases...

41 posted on 07/21/2002 2:12:06 PM PDT by general_re
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To: Ahban
In other words, what if one innocent person chose to die so that 1,000+ others could have a chance to live- Would that person have made a moral or immoral decision?

I don't think it's moral or immoral. It's a rational decision. The soldier makes a rational decision to place his life at risk for his family and country. When he is in a situation where he purposely places himself in the line of fire he is following through on his contract to risk his life. I suppose this could be considered ethical behavior.

Moral imperatives are for everyone. Actions beyond that, that is those which incur death or great harm to self for the sole benefit of others, may still be rational but they fall outside of morality.

42 posted on 07/21/2002 2:54:12 PM PDT by Nebullis
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To: Nebullis
Moral imperatives are for everyone. Actions beyond that, that is those which incur death or great harm to self for the sole benefit of others, may still be rational but they fall outside of morality

Thought provoking. Perhaps I should have asked the question differently.

43 posted on 07/22/2002 7:54:52 AM PDT by Ahban
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