Saturday, May 13, 2006

Tall tales

In this review of Robert Fogel's "The escape from hunger and premature death", Angus Deaton points out:

Inventing a Wellsian time-machine to take us all back to eighteenth century England would be as good for our health as transporting us to the moon without spacesuits. Our bodies are simply too large to survive on the average food supply then available.
...
If we were so transported, of course, most of us would adapt quite quickly to meager rations by becoming thinner, but only the short would be able to survive, so that the average height of the population would shrink, though more slowly than average weight. (Emphasis added)


I wonder if this explains the commendable preference women have for tall men. In an environment of chronic food shortages, height (more so than weight, which could vary with circumstances) would be a credible signal that a male has consistently had access to abundant food. In a class-ridden society, the tall men would also be the ones at the top of the social pyramid.

As food shortages become a thing of the past, variation in height will come to be explained more by genes, and less by access to resources. When this becomes the case, will natural selection ensure that height becomes less of a factor in assessing the attractiveness of men?

Note: I know I have been obsessing about signalling, but I find the concept quite fascinating. May post a couple more times about this topic, but shall eventually exhaust myself. :-)

Afterthought: Probably not, at least if this is correct. In the past, the primary constraint on how many descendents a woman had was access to resources. What with plenty of cheap food, and birth control, this is no longer the case. However, preferences have been set by past conditions, and what were indirect indicators of the male's ability to gain access to resources now appear to be primarily "aesthetic". In such a situation, those preferences would probably perpetuate themselves, even if they no longer signal wealth. Or not..

7 comments:

Jay said...

chronic food shortages lead to fights over food , in such a situation the stronger and the taller ( if i may presume that taller would also have connotations of strength) would be able to thram shorter people. take their food... the taller people become people who can provide...

Rajeev Ramachandran said...

But this is not a 10-20 year food shortage. Shortage of food was a normal condition in pre-industrial times (over thousands of years). Check out Greg Clark here- www.econ.ucdavis.edu/faculty/ gclark/GlobalHistory/Global%20History-2.pdf.
In such a case, the causation runs the other way- not "tall and strong, hence able to get hold of food", but "able to get hold of food, hence tall and strong."

Rajeev Ramachandran said...

Need not be sheer strength that leads to being able to get hold of food- could be the ability to form coalitions, the ability to do some work that requires skill (maybe why blacksmiths, etc. tended to ensure their skills stayed within the family), the ability to convince people they can intercede with the gods.. All would confer high status relative to the peasantry, and hence better access to resources..

venkat said...

"In the past, the primary constraint on how many descendents a woman had was access to resources. "

I have a different take on this. Poor people tend to have more kids. Even today. Is it something to do with the fact that there is a higher likelihood that they might die, and the only way to compensate for this is to have more kids. That way, chances are atleast one will come good, and pass on the genes. Not so for the millionaire's kid, for whom the only chance of death is likely to be od.

Rajeev Ramachandran said...

Thats true today, Venkat, but the reason we feel that is that poor people are still having the same number of kids as before, but more of them are surviving infancy- infant mortality is way down. The past, though, is a different country...Greg Clark's chapters seem to have been taken offline but, if I remember correctly, for well over 1000 years in Egypt, the typical woman had some 8 kids, but the population barely budged.. Thet indicates that almost all the kids who were born died before having kids of their own.

molu said...

what royal crap!!! i totally disagree...you want to believe that dont you...women are attracted towards POWER AND STRENGTH...thats coz by instinct they viev view such men as ideal candidates for their offsprings....

Rajeev Ramachandran said...

Na..The article that I linked to suggests the opposite..