How trade develops: thinking in terms of “we”

This is an absolutely fantastic classroom experiment by Bart Wilson:

In the traditional market experiment, the experimenters explain to the participants how to trade. For this experiment that seemed more than a little heavy handed if the question is, what is the process by which exchange “gives occasion,” as Adam Smith says, to discovering the “division of labour”? …Thus the first requirement in building the design was that participants would have to discover specialization and exchange…

The participants choose how much of their daily production time they would like to allocate to producing red and blue items in their field. They are then told, deliberately in the passive voice, that “you earn cash based upon the number of red and blue items that have been moved to your house.” What they have to discover is that not only can they move items to their own house, but that they can move items to other people’s houses…

At one extreme, the economy achieves 88% of the possible wealth above self-sufficiency by the last day[.] And at the other extreme, only 6% of the possible wealth above autarky is realized[…] Why the disparity? These students are immediately engaging their counterparts as part of an inclusive “we”. The same is not true in group 4 [which achieved less wealth].

He then goes into detail on the words and mode of thinking that different groups used to develop the idea of trade and markets. The conclusion is that the development of trade and specialization arises from considering the group and not the individual. And this is in a capitalist society! It is not to say that the only way for trade and specialization to develop is a kind of group-consciousness, and it is not to say that it wouldn’t have developed anyway. But it’s a bit of evidence that it can foster the conditions that make mutually beneficial trade networks increasingly likely.

As a second experiment, I would be interested in how quickly students familiar with the idea and the mathematics would find the optimal solution, and how it would evolve in a ‘noisy’ environment. I’d really like to see more advanced analyses of the text as well, the communication networks that evolve, and how they coordinate the development of the intellectual idea. Is there a tipping point? Is it a steady accumulation towards the optimum? Are there ‘laggards’ that are unconvinced?

But this is a great experiment and a great teacher.

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Transmitting behavior between groups

Crowds chanting in unison, wolves hunting in a pack, the superorganism that is the ant colony: these are all things that require the coordination of many individuals to accomplish something that they could not on their own.  And yet, replace any individual with another and the behavior will turn out pretty much the same.  Right?

Let’s look at the example of colonies of harvester ants that forage in the desert for seeds.  These ants adjust their collective foraging behavior through small interactions between individuals: ants decide whether to leave the colony to search for food if they sense other successfully returning foragers.  This way, if a lot of ants are returning with food, more ants will leave because the world is feeling bountiful.  But if few ants are returning with food, fewer new ants will leave to search; it’s just not worth it when there’s not a lot of food out there.  After all, leaving the colony carries a cost.  Every moment in the desert desiccates the poor ant foragers, and if they stay out too long they’ll up and die.

Screen shot 2013-07-17 at 10.30.46 AMAnt colonies don’t forage every day.  Their foraging depends not just on the abundance of food, but on environmental conditions such as heat and humidity.  Beyond this, there are colony-specific traits.  Some colonies will forage every day, some will just forage some days, and this trait persists across years.  This is trait is somewhat transmissible as colonies that reduce their forage on an uncommon day also have daughter colonies that are likely to reduce their foraging on uncommon days. This transmission of collective behavior suggests that responses to environmental conditions can be transmitted from one colony to the next.  This is the human equivalent of a teenager from Scandinavia founding a new town in the midwest and recapitulating parts of his culture there…

It’s not clear what the mechanism here is.  Since daughters of a queen continue to forage in a colony-specific manner, the transmitted component must be unrelated to the genetic contribution of the father.  So is it genetic, and linked to the X chromosome?  Or is it in some sense cultural, learning from the behavior of the greater colony it was raised in?  Hopefully someone who knows more about young ant behavior can enlighten us here…

Either way is interesting.  I can certainly imagine that a dynamic, collective behavior is controlled genetically.  Dopamine receptor expression is linked to foraging behavior, so genetic differences here could easily transmit motivation to forage.  And yet – cultural transmission would be pretty exciting, too.  This would indicate there is some sort of learned component and makes me wonder: if we can measure all the movement of an animal throughout its life, how well could we predict the behavior of a whole group?

References

Gordon DM (2013). The rewards of restraint in the collective regulation of foraging by harvester ant colonies. Nature, 498 (7452), 91-3 PMID: 23676676