Tuesday, October 23, 2007

The persistence of bad habits   posted by Razib @ 10/23/2007 06:55:00 PM

There are few issues in Farewell to Alms that I'm still chewing on. One of them is Greg Clark's dismissal of institutional and cultural barriers to development. In particular, Clark shows how practices such as usury, initially banned by the Church, were mainstreamed through work-arounds. I find this line of thought pretty persuasive, for example, look at what Israelis do during their fallow year. Proximately cultural practices are fixed parameters, but over time they generally evolve and shift. But there was something in Clark's argument which bothered me, he argues that the consistently worse hygiene of the English can explain their higher mortality rates vis-a-vis the Japanese, and therefore their elevated standard of living (more to go around for the fewer people left alive). Clark contrasts the efficient recycling of "night soil" and its distribution from urban areas out to farms where it could be used as fertilizer with the English practice of simply storing it within one's house until it could be thrown away like garbage.

But why do people persist in bad hygiene for centuries when it results in greater mortality? Shouldn't individuals who, for whatever reason, practice better hygiene slowly increase in numbers in relation to those who do not practice good hygiene? Are these habits simply not heritable? And I'm not simply wondering about hygiene here, what about practices like the Muslim ban on alcohol? From what I recall alcoholic beverages are not only good dense calorie sources, they also are less likely to carry high densities of pathogens then plain water. Muslims prided themselves on their customs of bathing and cleaning in relation to Europeans (in some areas of course bathing became dangerous because people might assume you had Muslim sympathies!), but it seems that their aversion to alcohol should have resulted in higher mortality from water born illness as well as poorer nutrition (exacerbated by Ramadan).

I'm sure some of this is explained by dynamics such as the Handicap Principle. Humans show off and do all sorts of irrational things to illustrate that "they're the man." Circumcision as a rite of passage for teenagers anyone? That being said, I am also curious as to the cognitive biases and social pressures which make usury inevitable (obviously a financial system spurs wealth creation) but hygiene seem less critical. Is it because usury is a concern of a small minority who are highly motivated and a simple fiat change of the law can result in a switch? In contrast, hygiene is embedded in a whole suite of mores, practices and traditions, and requires self-control and conscious forethought. Even today it is relatively difficult to get many to wash their hands after they use a restroom!