Field of Science

Brits and Yanks on the Titanic

Discovery News Top Stories: Manners Lowered Brits' Chances of Survival on Titanic, said my Gmail ad banner. Intrigued, I clicked the link.

It seems behavioral economists David Savage and Bruno Frey, looking through historical records, found that Britons had the highest death rate of any nationality aboard the Titanic, even though the ship's crew was British. There is anecdotal evidence that British politeness contributed to their mortality: Witnesses heard the captain saying "Be British, boys, be British!"--meaning for them to "queue up" and wait for women and kids. Meanwhile, Americans, whom some saw elbowing their way forward to board the lifeboats, had the highest survival rate of any nationality.

Behavior in all animals reflects a delicate balance between cooperative and selfish instincts. Human history, in particular, shows extreme examples of both greed and selflessness. These behaviors, like all others, are evolved; and reflect the multilayered incentives for selfish and altruistic behavior that run throughout evolutionary history.

Assuming Savage and Bruno are correct, it appeared the jerks took the day in this instance. If we suppose that evolutionary history contained many such "Titanic moments", in which the self-interested could elbow out the polite in the struggle for survival, one might conclude that only the selfish would emerge from evolution unscathed.

But there's more to the picture. We'll never know if more could have survived the Titanic had everyone on board worked together. Certainly fewer would have survived had everyone been fighting for a spot on the lifeboats. If we imagine many Titanics sinking in simultaneous, independent events, it's possible that more altruists would survive overall, because boats of mostly altruists would save a higher percentage of passengers than boats filled with arseholes. So there is a sense in which, while selfishness works on an individual level, cooperation may do better on a large scale. (This is essentially the group selection argument I refered to in this post--one of many explanations for why both altruism and selfishness are seen in the products of evolution.)

One can also ask how the social norms in America and Great Britain evolved to be this way. British and American people separated far too recently to have diverged genetically, but the two nations have certainly evolved culturally along different paths. An argument could be made that America, with its vast expanses of open (except for Native Americans) land and looser socioeconomic hierarchy, rewarded bold and individualistic behavior more than old, statified Britain.

Neither British nor American social norms were evolved specifically for the Titanic. Behaviors adapted for one context played out in another, resulting in a higher proportional survival for Americans, perhaps a lower total survival than if all the passengers were British.

In considering the behaviors we'll need to survive in a world of global interconnection and environmental fragility, it's important to remember that behavior evolves in context. If we can anticipate the kinds of behaviors we'll need in the future, can we also anticipate the changes we'll need to make to start evolving these behaviors now?

Update: The Emerging Field of Cultural Evolution

In my last post I asked how a society that evolves through its ideas would differ from one that evolves through its genes. Today I came across a cache of Wired Science blog posts highlighting recent efforts to address this very idea, in a new field that is being called "cultural evolution."

  • Paul Ehrlich studied the evolution of canoe design in Polynesia, as a model system for how cultural evolution works in general. He found, not surprisingly, that artistic variation occurred rapidly, whereas variation in the the canoes' functional design was slower (due to the need to be sea-worthy.) (blog post,journal article)

  • Simon Kirby et. al. simulated the evolution of a new language. Human subjects were shown a collection of nonsense words, and a picture associated to each word. They were then asked to recall these word-picture associations. Whether or not these recollections were correct, they were used as the basis for a new set of words-picture associations, which were then shown to a new set of subjects. As the associations changed each round based on what people could remember, a structred language began to develop.

    In other words, human memory was the environment in which the language was evolving. The more structure in the language, the easier it was to remember, and therefore the more it got passed on. Very cool! (blog post, journal article)

  • Arne Traulsen et. al. (the et. al. includes Nowak) found that if you assume a much higher rate of "mutation" in ideas than in genes (a reasonable assumption), you get qualitatively different results. For example, cooperation can become viable in situations where it wouldn't otherwise be. (blog post)

The Future of Human Evolution

For much of the history of life, evolution worked a certain way. Organisms competed for the chance to reproduce. An individual with an advantageous mutation would produce more offspring, which would inherit the advantageous gene, and in this way life continually improved upon itself.

But I would argue that for humans, in the world as it is today, this process is more or less defunct. We are not, by and large, competing with each other to produce more offspring. It's true that some people lack reproductive ability or die before their time, but most people who reach adulthood with their health intact can have as many babies as they want. It is a matter of choice more than a competition. Furthermore, people with genetic defects, who may never have survived in times past, can now (sometimes) lead healthy procreative lives thanks to modern medicine.

This means that the best genes no longer produce more copies. There is no longer a way for advantageous mutations to spread through the population. If these trends continue, we can expect that our gene pool will no longer improve, and may even degrade a bit thanks to advanced health care. The human body and mind are currently as good as they will ever get.

So have humans stopped evolving? As individuals, I would say yes. But our society is clearly still evolving, due a mechanism we evolved in the past million years (back when we were still evolving the normal way): language.

Language allows for the evolution of ideas rather than genes. A person with a good idea can communicate it to others, who, if they like it, can communicate it further. In this way good ideas, rather than good traits, spread through the population.

Here's another way of seeing the difference: for conventional evolution, DNA carries information about traits that successfully spread themselves. For this new form of evolution, language (both oral and written) carries information about ideas that successfully spread themselves.

I don't think any of the above ideas are terribly original. But it occurred to me today that while there are many mathematical models for genetic evolution, I don't know of any good models for the evolution of ideas. And more generally, how does a society that progresses by idea-based evolution differ from one that evolves genetically? The question is so vague I can barely conceive of how to frame it, but it seems very important to the study of humanity's future.