March 20, 2012

Cumulative culture and cooperation in humans and other primates

Two recent papers compare the problem-solving abilities of humans and other primates. Individual humans are smarter than individual chimps, of course. But our most-impressive intellectual feats depend on the accumulation of cultural knowledge over many generations. A blacksmith might make some of her own tools, but she didn't invent most of them, or smelt the iron from ore she mined herself. Computer programmers, in turn, depend on technology that built on the work of blacksmiths and many others.

I once read a story in which Earth was visited by aliens with vastly superior technology. Initially, humans assumed that the aliens must be much smarter than we are. It turned out that most of them were pretty stupid, easily duped by humans. It's just that their civilization was older, so they'd had time to invent spaceships and such, even with fewer geniuses than we have. How much of our technological superiority to nonhuman primates is due to superior individual problem-solving ability, and how much to cumulative culture?

"Identification of the Social and Cognitive Processes Underlying Human Cumulative Culture" was published in Science by L.G. Dean and others. They compared the ability of groups of 3-4 year-old human children, chimps with capuchin monkeys, in solving a "puzzle box", where retrieving the most-valued food reward depended on solving three successive levels of increasing difficulty. Only one chimp of 33 got to level 3, while many humans did. Why?

Humans copied others more than chimps or monkeys did. Chimps tended to copy the moves needed to get to the first level, but not beyond that, so it didn't help much to let them see a chimp that had been trained to reach level 3. All 23 clear cases of "teaching" (2/3 verbal and 1/3 via gestures) were by humans. Humans were more generous in other ways also: 47% shared food with others, while none of the chimps or monkeys did. Chimp mothers stole from their own offspring. In summary:

"The children responded to the apparatus as a social exercise, manipulating the box together, matching the actions of others, facilitating learning in others through verbal instruction and gesture, and engaging in repeated prosocial acts of spontaneous gifts of the rewards they themselves retrieved. In contrast, the chimpanzees and capuchins appeared to interact with the apparatus solely as a means to procure resources for themselves, in an entirely self-serving manner, largely independent of the performance of others, and exhibiting restricted learning that appeared primarily asocial in character."

Human adults may be different, however, with rich (or well-educated?) adults acting more like chimps. See last week's post.

The second paper also compares cooperation in humans and other primates. "Old World monkeys are more similar to humans than New World monkeys when playing a coordination game" was recently published by Sarah Brosnan and others in Proceedings of the Royal Society B. Pairs of humans, rhesus monkeys, and capuchin monkeys played the Assurance (or Stag Hunt) game, using computer joysticks to enter their moves. An individual choosing Hare gets a reward whatever the other player does. But if both choose Stag, they each get double the reward.

All of the human pairs talked, but only some talked about the game. Of those that did, all 22 pairs ended up playing mostly cooperatively -- but not 100%, even after seeing the potential benefit. Those who talked about other topics played mostly noncooperatively, forgoing the benefits of cooperation.

The two monkey species differed. For both species, if individuals could see the other's move, they learned to "cooperate" and got high rewards. (They could see each other, but did they realize they were playing with each other, rather than with the computer?) The capuchins played more randomly when they didn't know the other's move, whereas two pairs of rhesus monkeys quickly learned to trust their partner and cooperate (or, anyway, to play as if they did). Rhesus monkeys are native to Africa, rhesus monkeys to South America. So, as the authors put it:

"Old World primates outperformed New World primates,
rather than humans outperforming non-humans."
They speculate that, perhaps:
"...humans' abilities are built on a shared foundation that extends back at least as far as the split with Old World monkeys [which was longer ago than the split between apes and old-world monkeys, let alone the split between humans and other apes]."
An interesting hypothesis, but I would like to see data for more species.

March 24, 2011

Education as a tragedy of the commons

The New York Times is discussing whether we spend too much on education, or not enough. It might help to phrase the question more explicitly, either as:

1) Would individual families benefit from investing more in their own education?

2) Would society as a whole benefit from investing more in education?

Two commentators point out that individuals with more education have substantially higher salaries, on average. Maybe those individuals would have had higher salaries even if they hadn't gone to college, of course, or even if they'd gone to a less-expensive college. That question has been debated elsewhere, and I don't have anything to add.

But even if college is a good investment for individuals, it isn't necessarily true that we would be better off, collectively, if we spent more, collectively, on education. Assume, for the sake of argument, that the number of high-paid jobs is fixed at 10% of the working-age population. If those with more education are more likely to get those jobs, then investing in education makes sense for individuals and their families.

Education could be a sound individual investment even if the education itself was worthless and incomes were determined only by credentials relative to others. But, if producing more people who are qualified to be medical doctors doesn't increase the number of jobs for doctors, then the higher pay of college-educated doctors relative to less-educated nondoctors doesn't make educating more people a good investment for society as a whole.

Individual benefits from investing in education don't necessarily translate into societal benefits from investing in education.

How might society benefit if more people were more educated? My guess is that, if more people were better educated, we would have less crime, a stronger economy, and better political decision-making. My guess is that these societal benefits would outweigh the societal costs of investing more in education. But you can't estimate the total return on these societal investments from the economic return to individuals from investing in their own education. Societal benefit:cost ratios could be lower or higher than those for individuals.

Here's another important point. The return on investments in one kind of education for one group doesn't necessarily predict the return on investments in other kinds of education for other groups. Years ago I saw a comparison of countries that started with similar economies and invested similar amounts of public money either in universities or in primary education. Investing in primary education led to lower birth rates, so the education budget was spread among fewer kids. They developed educated workforces and their economies grew, so that eventually they could afford universities as well. (Until then, citizens wanting more education got it in other countries, thereby making contacts that improved trade.) In contrast, the countries that focused on universities only educated -- "credentialed" might be a better word -- the children of the ruling kleptocracy. The overall population stayed ignorant, birth rates stayed high, and economies stagnated.

Fortunately, I live in a rich country that can afford both great universities and great primary and secondary schools. An honest cost:benefit analysis would be a good place to start.

December 10, 2010

Conditional cooperation in commons management: Ostrom versus Hardin

"To many, the word coercion implies arbitrary decisions of distant and irresponsible bureaucrats; but this is not a necessary part of its meaning. The only kind of coercion I recommend is mutual coercion, mutually agreed upon by the majority of the people affected." -- Garrett Hardin, The Tragedy of the Commons

Garrett Hardin's "The tragedy of the commons", published 42 years ago in Science, is one of the most influential papers of all time. He made four main points, of which the first two have received the most attention:
1) Some important problems cannot be solved by purely technological means. For example, increasing crop yields is at best a temporary solution to the problem of feeding an ever-growing population.
2) Adam Smith's "invisible hand", whereby individuals following their own interests benefit society as a whole, doesn't always work. This is because the individual benefit from grazing a cow on shared land (a "commons"), or from harvesting a rare fish species, or from a manufacturing process that pollutes the air, can exceed the individual cost of that one cow's damage to the grazing land, the slightly increased extinction risk for the fish species, or breathing slightly more-polluted air.
3) Human decisions about reproduction are similar to the above examples, because they are largely based on individual costs and benefits. Any genetic or cultural lineages that restrain their reproduction for the public good will be overwhelmed by lineages that do not.
4) It is widely recognized that some limitations on grazing, fishing, and pollution are needed to bring individual behavior in line with the long-term common good. Similarly, some restriction of the freedom to breed will be necessary to limit population growth.

Except in China, which apparently missed the "mutually agreed upon" part, most people have ignored Hardin's main point, the claim that some form of mutual coercion is needed to limit human reproduction. Instead Elinor Ostrom and others have done lots of good research on the ways that various groups manage common resources, such as forests or fishing grounds. When she spoke here recently, by video link, I was surprised to hear her accuse Hardin of advocating government (as opposed to community) control of common resources. I'm sure he advocated government control in some cases, but his statement quoted above is equally consistent with community-based solutions. The key point is that there must be some individual incentives for individuals to act in ways consistent with the common good.

An example of recent work on commons management is a paper, also published in Science, titled "Conditional cooperation and costly monitoring explain success in forest commons management", by Devesh Rustagi, Stefanie Engel, and Michael Kosfield. They compared 49 different community groups in Ethiopia, each of which manages a forest. In the absence of some mechanism to prevent individuals from, for example, harvesting too many trees, Hardin's hypothesis would predict over-harvesting and deterioration of the common resource.

The researchers used the number of young trees per hectare (PCT=potential crop trees) as a measure of management success. Most such trees were cut for charcoal before the community-management program began, so regrowth of young trees requires communities to forgo some immediate gain for longer-term benefits.

The abstract of the paper reports that this measure of successful management was correlated with "conditional cooperation." This seemed a bit odd to me. In a group of only two people, it's simple enough to say "I won't over-harvest if you don't", but that sort of tit-for-tat cooperation doesn't directly translate into larger groups. It turns out, though, that the authors measured conditional cooperation using a two-person version of the public goods game, where conditional cooperation essentially amounted to punishing non-cooperation by the other player. That attitude (or cultural norm) seems likely to translate into some tendency to enforce forest-management rules in the real world. And indeed, individuals classified as conditional cooperators based on the game spent more time patrolling the forest, enforcing rules against over-harvesting.

What about the "community" versus "government" distinction? Is the "executive committee on the group level chaired by the group leader" charged with "punishment of free riders" part of a community, a form of local government, or both? In any case, the "distant bureaucrats" apparently disdained by both Ostrom and Hardin did apparently play at least two key roles. The article states that:

"...groups of the Bale Oromo people were given secure tenure rights to use and manage their forests as common property resources (39). In return, these groups are required to maintain their forest cover, for which they are allowed to implement local rules regarding forest use"

So the national or regional government (1) protected group land tenure (for example, against the sort of problem Ostrom mentioned in her talk here, where a local community managing their fishery sustainably was unable to exclude outsiders who over-harvested), and (2) enforced result-based management standards, though without micromanaging. For example:
"...assessment is carried out once every five years by the forest administration with active participation from group members. The main purpose of this assessment is to determine the annual allowable timber quota and the rent each group has to pay to the local forest administration".

March 22, 2008

Oestrus Island

"A struggle for existence inevitably follows from the high rate at which all organic beings tend to increase... It is the doctrine of Malthus applied with manifold force to the whole animal and vegetable kingdoms" -- Charles Darwin, Chapter 3, The Origin of Species
This week's paper is more about ecology and sustainability than evolution per se. In recognition of Easter, a holiday originally honoring Oestre (the goddess of spring, who also lent her name to oestrus), and still retaining much of its original association with fecundity, I will discuss "The simple economics of Easter Island: A Ricardo-Malthus model of renewable resource use" written by J.A. Brander and M.S. Taylor and published in 1998 (Am. Econ. Rev. 88:119). The other logical choice for the holiday would be a discussion of mammals that lay eggs, such as the platypus a missing link that makes a brief appearance in a great recent post on Pharyngula, which discusses some of the evidence that we are descended from egg-laying ancestors.

Continue reading "Oestrus Island" »

February 15, 2008

Mutually-assured-destruction fund

This would combine the benefits of old-age insurance, mutual funds, and Russian roulette

The problem: even if average retirement savings were adequate, a few long-lived individuals would outlive their savings.

Insurance seems a logical solution, at first, because only a few people will live much longer than average. Insurance works well to spread current risks, such as home fires, where it’s easy to audit reserves, payouts, etc. But it’s hard to audit a promise that benefits will be available decades in the future, especially if governments are more concerned with the next election than with oversight. So pension programs (essentially old-age insurance) turn into pyramid schemes, which may fall apart as more people start collecting benefits. Government pension programs can keep making payments by raising taxes or by printing money. However, either “solution? can hurt the overall economy, e.g., by increasing inflation.

Mutual funds with stocks and bonds have the potential to keep ahead of inflation. But to supply enough income indefinitely, you need to invest a lot more money than if you were able to use it up during your lifetime. The problem, of course, is that you don’t know how long you’ll live.

Continue reading "Mutually-assured-destruction fund" »

October 5, 2007

Aristotle on the tragedy of the commons

"What is common to the greatest number gets the least amount of care. Men pay most attention to what is their own; they care less for what is common; or at any rate they care for it only to the extent to which each is individually concerned. Even when there is no other cause for inattention, men are more prone to neglect their duty when they think that another is attending to it."
-- Aristotle, Politics (Oxford: Clarendon Press, 1946), 1261b.

August 23, 2007

Failure to communicate as a tragedy of the commons

Bruce Schneier suggests that incompatibility among communication systems used by emergency workers is the result of a tragedy of the commons. He calls it a "collective action problem."

Although there may be subtle differences, "tragedy of the commons", "collective action problem", "prisoners' dilemma", "coordination problem", and the "free-rider problem" all seem similar enough that a solution to any of them would be at least a partial solution to all of them. It's a shame that researchers working on similar problems can't all agree to use the same terminology, to facilitate communication among disciplines. But the first brave researchers to switch to the common terminology would find their papers dropping into obscurity within their own disciplines, where decisions about grants and promotions are made...

August 22, 2007

Evolution of cooperation reviewed

The theme of the latest issue of Current Biology is "Biology of Societies." There are reviews on the social life of spiders, crows, hyenas, amoebae, and insects, plus the role of cognition in social interactions among humans. If you are interested in the evolution of cooperation, it might be worth a trip to your nearest university library (if you don't have access via the web) to browse this issue.

I particularly liked "Evolutionary Explanations for Cooperation" by Stuart West, Ashleigh Griffin, and Andy Gardner. Their review reprints figures from several recent papers, so you can see some of the data upon which their generalizations are based. I won't try to summarize the whole thing, just some points that may have been neglected in other reviews of this topic.

Continue reading "Evolution of cooperation reviewed" »

July 21, 2007

Diversity, stability, productivity, and policing

Any hypothesis worthy of the name makes predictions. Testing these predictions may take a long time or lots of money. Edmond Halley's 1716 prediction that a transit of Venus could be used to measure the distance to the sun could not be tested until the next transits of Venus in 1761 and 1769, and required global scientific expeditions. (Mark your calendars for 6 June 2012!) The Rothamsted Experiment Station has been testing the hypothesis that wheat can be grown with only inorganic inputs and without rotating to other crops, since 1843. This may not be long enough to uncover all possible problems with inorganic fertilizers and continuous monoculture, but it's quite a contrast with an acquaintance who wrote that "I've been farming sustainably for three years."

If even one of a hypothesis's predictions turns out to be unambiguously wrong, the hypothesis must be discarded or revised. On the other hand, multiple correct predictions do not prove that a hypothesis is true -- there might be other hypotheses that make the same predictions. Either way, it's useful to consider several hypotheses, if you can. Tom Kinraide and I discussed these points in an article in American Biology Teacher in 2003. His boss wouldn't let him include his USDA affiliation, because someone at the lab complained that testing hypotheses would undermine his religion. I don't know; maybe it would.

In interpreting the data in this week's paper, we need to remember that conflicting hypotheses can sometimes make some of the same predictions, a point which is also reinforced in a recent review article. Both papers consider the benefits of biological diversity.

Continue reading "Diversity, stability, productivity, and policing" »

June 12, 2007

Better methods for pragmatic problem-solving?

That's what David Brin thinks is our "most urgent scientific and technical need" according to an interview in Wired Science. He doesn't go into a lot of detail, but neither do the many strangely hostile comments.

Continue reading "Better methods for pragmatic problem-solving?" »

March 30, 2007

Political applications of social escrow

Politics is dominated by special interest groups that make large campaign contributions. A presidential campaign in the US can cost over one billion dollars. That's only $3 per American, so you might think that a $10 contribution from each family to their favorite candidate would make special-interest money irrelevant. Wrong!

Continue reading "Political applications of social escrow" »

March 23, 2007

Viruses as technical solutions: just science fiction?

According to Hardin's paper, individuals, each pursuing self-interest, will often act in ways that undermine our collective welfare, causing problems like collapse of fish stocks or human overpopulation. He thought the solutions were essentially political, "mutual coercion, mutually agreed upon." He had little faith in technical solutions.

Mutual coercion seems to work to limit some kinds of antisocial behavior (e.g., violent crime) in many societies, but the only societies that coerce people into having fewer children (e.g., China), or more children, for that matter, -- Rumania in the 1980's is one of the more extreme examples -- can't claim that the coercion is mutually agreed upon. Furthermore, some kinds of antisocial behavior are so difficult to monitor that coercion might not be practical even if it were widely supported by the public.

Technical solutions to these sorts of problems, based on viruses that alter human behavior (e..g. a virus for altruism) or reduce human fertility have been proposed in science fiction.

Could this actually happen? This question really has two parts:

Continue reading "Viruses as technical solutions: just science fiction?" »

March 16, 2007

Driver behavior a tragedy of the commons after all?

Apparently some of what I wrote last week is wrong. I contacted Dr. Martin Treiber, a traffic expert in Germany who is working on an "adaptive cruise control (ACC) system that is designed not only to provide a comfortable acceleration and deceleration behaviour to the driver, but also to improve the overall traffic flow." He writes that there is sometimes a conflict between the two objectives of: 1) improving the experience of individual drivers and 2) overall traffic flow. Apparently the driving pattern that optimizes traffic flow feels unnatural to the driver.

Continue reading "Driver behavior a tragedy of the commons after all?" »

March 9, 2007

Tail-gating tragedy reversed?

We know that one selfish driver can slow everyone down by weaving in and out of traffic, but is the reverse also true? William Beaty claims to have figured out how one driver can eliminate those annoying, slow moving "clots" of cars. He simply maintains a longer-than-usual following distance when he approaches a clot. That prevents the clot from growing at the rear, while it gradually evaporates at the front. I would have thought that might lead to another clot behind him, but he says actual road tests show it improves traffic flow both in front and behind. Apparently the key is driving at a constant rate, which would be impossible if he were tail-gating the clot, but isn't that hard to do if you leave enough space in front of you to buffer speed fluctuations of the car ahead.

Continue reading "Tail-gating tragedy reversed?" »

March 1, 2007

The Tragedy of the Commons vs. The Three Musketeers

[Yossarian:] "We won't lose. We've got more men, more money, and more material. There are ten million men in uniform who could replace me. Some people are getting killed and a lot more are making money and having fun. Let somebody else get killed."
[Major Major:] "But suppose everybody on our side felt that way?"
[Yossarian:] "Then I'd certainly be a damned fool to feel any other way. Wouldn’t I?"
-- Catch-22

“In fact, four men such as they were - four men devoted to one another, from their purses to their lives; four men always supporting one another, never yielding, executing singly or together the resolutions formed in common; four arms threatening the four cardinal points, or turning toward a single point - must inevitably, either subterraneously, in open day, by mining, in the trench, by cunning, or by force, open themselves a way toward the object they wished to attain, however well it might be defended, or however distant it may seem. The only thing that astonished D'Artagnan was that his friends had never thought of this.?
-- The Three Musketeers

I suggest that the key words in these contrasting views of cooperation are “ten million? and “four.? One person in ten million deserting won’t change the course of a war, but if one swordsman in a group of four consistently puts his own safety ahead of the success of the group, the group is more likely to lose a fight, with severe consequences for everyone in the group.

Continue reading "The Tragedy of the Commons vs. The Three Musketeers" »