Numbers, not value, motivate cooperation in humans and orangutans
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- The Ohio State University, Psychology
- The Ohio State University
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- Manuscript
- Date:
- Received 05 December 2007 21:07 UTC; Posted 05 December 2007
- Subjects:
- Developmental Biology, Ecology
- Abstract:
Cooperation among competitors-whether sharing the burden of wind resistance in the Tour de France, forming price-fixing cartels in economic markets, or adhering to arms-control agreements in international treaties-seldom spreads in proportion to the potential benefits. To gain insight into the minds of uncooperative agents, economists and social psychologists have used the prisoner’s dilemma task to examine factors leading to cooperation among competitors. Two types of factors have emerged in these studies: the relative rewards of defecting versus cooperating and breakdowns in trust, forgiveness and communication. The generalizability of economic and social psychological factors, however, relies on the assumption that agents’ comparisons of gains and losses (whether for themselves, others, or both) preserves ratio information over arbitrary units, such as dollars and cents, and real rewards, such as food. This assumption is inconsistent with psychophysical studies on how the brain represents quantitative information, which suggests that mental magnitudes increase logarithmically with actual value. Thus, discrimination of two numerical magnitudes improves as the numerical distance between them increases and decreases as the magnitudes increase. Here we show an important consequence of this representational system for economic decision making: in the prisoner’s dilemma game, purely nominal increases in the numerical magnitude of payoffs (such as, converting dollar values to cents or whole grapes into grape-parts) has a large effect on cooperative behaviour. Moreover, a logarithmic scaling of the ratio of rewards for cooperation versus defection predicted 97% of variability in observed cooperation, whereas the objective ratio predicted 0% of variability. By linking the brain’s system of representing the magnitude of rewards to motivations for cooperative behaviour, these findings suggest that the nature of numerical representations may also account for the subjective value function described by Bernoulli, in which the apparent value of monetary incentives increases logarithmically with actual value.
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- This document is licensed to the public under the Creative Commons Attribution 3.0 License
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Furlong, Ellen and Opfer, John. Numbers, not value, motivate cooperation in humans and orangutans. Available from Nature Precedings <http://hdl.handle.net/10101/npre.2007.1392.1> (2007)
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Ajay Kohli on 30 January 2009 05:31 UTC
Interesting –
I was about to post a comment, rather a question in response to the article when I saw the box for ‘voting’. Me voting for this article is a sort of cooperative behavior. Why am I cooperating with the previous 3 voters in ‘applauding’ this article. I guess there may be a psychological reward – for all 4 of us – in the knowledge that we are a number of people who think that this article makes sense. If I believe this article is useful then voting for it rewards me with membership of a group of 4, not voting ‘doesn’t give me anything’. There are surely more than 4 people who read this article and thought of it as a sensible argument. Would more such people vote for it if the article already had 40 votes? OR, would more people read it if had 40 votes instead of 4? Would I have voted if there were no votes. The answer to the last question at least is a YES, but why…. I guess the driver remains the same as above – adding to the number of people who think like me.
BUT – what is the value of adding to this number and/or what is the value of the article per se with more or less votes, I am really not sure. So we do seem to be going by numbers not value. Any comments?
Coming to the original thought I had in mind after reading the article. Here’s a factual situation:
The exchange rate of USD to Philippino Peso is the same as that to Indian Rupee (ca. 1:50).
At most green markets in Delhi (unless you are at real upscale locations) INR 100 buys you 7-8 kg of locally produced tomatoes. At similar green markets in Manila, Peso 100 buys you only 4 kg of locally produced tomatoes. The monetary numbers are the same (100) but their value (kg tomatoes) is different. The situation can be extrapolated to many other products (in fact I am yet to come across anything, vegetables to furniture to electronics) that is cheaper in Manila than in Delhi). There may be many economic factors contributing to this situation and since I am not an economist I won’t get into that.
Compare that to the fact that INR 100 = USD2 = 1-2 kg locally grown tomatoes.
The question I have in two parts is this:
a. What would be the predictions for cooperativity in a group of Indian compared to Pilipino people for a prize money of Peso/INR 100/-. This compares the value of the prize money when the number is more or less the same
b. What would be the predictions for cooperativity in a group of Indian/Pilipino people for a prize money of INR/Peso 100/- compared to cooperativity between a group of people in US for a prize money of USD 2/-
Again, extrapolating the situation wrt your article, would it be fair to say that cooperativity will break down more easily in the US. I know it’s a daft question because comparisons could best be made between USD 2 and 200 perhaps, yet I wonder if numbers have implications on societies when it comes to comparing international societies for behavioral traits, not necessarily influenced by cultural practices. For example, the question becomes very relevant when higher-middle class salaries in India today are more or less the same as in the US but an US employee will be taking home USD 5000/- while an Indian employee will be taking home INR 250,000/- (1:50). At such numbers, apparently INR 250,000/- will elicit more cooperativity among Indians than USD 5000/- would do among North Americans. Could this be the reason for a tight, supportive, friendly and hospitable (even to strangers) higher-middle class in Delhi compared to a fragmented, ‘minding-one’s-own-business’ high-middle class in NY. I refer to higher-middle class only for the sake of somewhat valid comparison because Delhi now offers – in its own cultural contexts – similar extra-professional/recreational activities/facilities to this class of individuals and families, as available to the US group in this class. So time constraints for others due to catering to one’s own family and oneself in Indian Metros are similar to those in NY.
Countries such as Italy where transactions were in millions (of lire) at the corner shop before the Euro, which now limits similar transaction to less than 10 Euros, could be a good case study in terms of societal changes, other things remaining the same.
Apologies for pouring out the thoughts like this, but the interest was piqued after reading the article and perhaps you would have some enlightening professional reactions.