When are we likely to share resources?  At first glance, some of us might say that we share when we have more of something than other people around us.  It’s not that simple, however.

In “Evolutionary Psychology, Moral Heuristics in the Law,” Leda Cosmides and John Tooby discuss moral heuristics and the evolution of the legal system.  It is a well-written article throughout, though I’d like to focus on one aspect of the article that I found especially interesting.  I’d like to focus on their discussion the circumstances under which people are willing to share and when they are not.

Cosmides and Tooby note that the “hunter-gatherer life is not an orgy of indiscriminate sharing, nor is all labor accomplished through collective action.”  On the other hand, the hunting of large animals often is a social activity and the meat, whether caught by a few or by a large cooperating group, is often shared throughout the social group.  These transfers of meat are “not characterized by direct reciprocation in any obvious way.” Cosmides and Tooby go so far as to suggest that the sharing of meat may be closest to that predicted by Marx’s belief that hunter-gatherers “lived in a state of primitive communism, where all labor was accomplished through collective action and sharing was governed by the decision rule,’ from each according to his ability to each according to his need.'”

The widespread sharing of meat appears to challenge the evolutionary model, which would hold that “selection would not favor indiscriminate sharing.”  Cosmides and Tooby argue that different kinds of rules regulate sharing in different kinds of situations.  Each of these subprograms embedded in us “produce different moral intuitions about when to provide help and to whom, and each is activated by different situational cues.”  We have different programs, they argue, for sharing meat versus sharing gathered goods. Why would it be that meat and gathered food would be shared in different ways?  It boils down to the perception of luck, according to Cosmides and Tooby.

Success in hunting is relatively unpredictable.  Even great hunters often return empty-handed.  Therefore, success in hunting (whether for meat or honey) often depends upon factors outside of the hunters’ control.  The Ache hunters of Paraguay, for example, return empty-handed 40% of the time. In this situation, “an individual is better off redistributing food from periods of feast to periods of famine.”  This can be done in two ways: through food storage or by pooling resources with others, although the former is often not feasible when it comes to spoil-prone meat in hot climates. Cosmides and Tooby suggest that meat “can be stored in the form of social obligations.”  In fact, the same sharing rule will evolve wherever the social group faces “frequent and random reversals of fortune.”  This rule is triggered “by the perception that the suffering is caused by bad luck, rather than lack of effort.

Contrast hunting with the lack of variance of success that one encounters regarding gathered goods.  Luck plays a relatively small role in gathering.  Harder work tends to reward the worker proportionately.  Similarly, gatherers who are more skilled tend to gather more.  Because of this,

band-wide food sharing would simply redistribute food from those who expend more effort or are more skilled to those who expend less effort or are less skilled . . . there is little reason to expect that the future will be different from the present and, therefore, little reason to expect that those with less food now will be in a better position to reciprocate in the future.  Under these circumstances, selection will favor adaptations that cause potential recipients to welcome sharing, but potential donors to be reluctant to share.

Cosmides and Tooby cite studies supporting these differences in their willingness to share.  They suggest that these deep biological programs take the form of the following propositions:

1.  If he is the victim of an unlucky tragedy, then we should pitch in to help him out.
2.  If he spends his time loafing and living off of others, then he does not deserve our help.

The authors correctly point out that these expressions seem self-evident, that “there seems to be nothing to explain.”  On the other hand, see what happens when these expressions are reversed:

3.  If he is the victim of an unlucky tragedy, then he does not deserve our help.
4.  If he spends his time loafing and living off of others, then we should pitch in to help him out.

Cosmides and Tooby point out that although 3 and 4 sound eccentric, they present “no logical contradictions.”  The inferences they embody seem to violate a grammar of social reasoning.  Their conclusion is that “the grammar structuring these moral intuitions [1 and 2] was selected for because of the fitness effects [they] had ancestrally.”

I find these observations and conclusions intriguing for several reasons.  First of all, there does not seem to be a general sharing rule, as claimed by many moral flaws first.  Instead, there seem to be several types of sharing rules, just as Cosmides and Tooby suggest.  Second, commonly encountered sharing behavior does seem to treat needy people differently, based upon the perception (by potential sharers) that the resource was obtained through luck.

Consider, for instance, the attitude of many people who have won the lottery, compared to those people who have worked hard and scrimped all their lives to obtain the same amount of money.  Lottery winners are much more likely to use the rule “easy come, easy go.”  The same attitude can be seen at tax time each year.  People are much more likely to share (or “blow”) their refund, which is often perceived to be a matter of good fortune, compared to a comparable amount of money that they might put into their bank account, week after week, throughout the year.

Consider also the attitudes of different kinds of wealthy people.  Families that have been working hard to preserve their family money over the generations treat money differently than the nouveau riche, who be much more likely to see their relatively sudden attainment of money to be a matter of good fortune.

Over the past year I’ve attended several auctions on behalf of benevolent organizations, where the winner of a substantial cash prize was announced.  Invariably, the winner stands up and proudly gives that money to the good cause.  I’m not claiming that there aren’t potentially other factors at play here (including substantial social pressure that might boil down to a Darwinian display of fitness).  On the other hand, the theory of Cosmides and Tooby would suggest this result.

Generally, people who perceive that they have come into money as a matter of fortune or luck are much more willing to share.  Those who have worked hard to incrementally accrue comparable amounts of money are loath to share with those they perceive to be lazy.  Further, we readily come to the rescue of those who have been injured due to a sudden calamity that we perceive to be a matter of bad luck, such as a hurricane, even when such victims have used bad judgment in allowing themselves to be in a position to be damaged by the hurricane.  We are much less likely to help out someone who made a long string of bad decisions resulting in an equally desperate situation.  We are not usually willing to consider conscious decision-making as a matter of luck given the prevalent belief in “free will.”

I’m going to think some more about this approach presented by Cosmides and Tooby.  I suspect that they are on to something.  It is certainly much more compelling than the often disproved proposition that people are generally willing to share.