Does Size Really Matter in Interethnic Marriage?

My friends think it odd that when it comes to looking for a man I don’t really care about finding one who is tall. Sure, I understand that there is a biological incentive for women to find a tall mate. But since my current survival does not depend on having a man who can scale a cliff face in pursuit of an antelope on my behalf, I am perfectly happy to consider dating shorter men. I also understand that when removing a constraint on a system (such as “I will only date a man who is at least X feet tall”) the outcome must be at least as efficient, so it’s not possible for me to be worse off by making this decision. Call it Le Chatelier’s principle as applied to dating and marriage.

But the fact remains that my own lack of height preference makes me a bit of an outlier; many women do care about height when searching for a mate, and a new paper argues that this fact explains at least some of the racial segregation that we observe in marriage. Using data from the UK, the authors suggest that the low levels of interethnic marriage can be explained, to some degree, not by racial discrimination but rather discrimination over height.

In other words, if white women are not marrying Asian men it could simply be because white men are taller on average than Asian men, not because white women have a distinct preference for white men over Asian men.

Here is the basic evidence this paper presents: Men who marry a woman outside of their own race are, on average 1.38 cm taller than the average man and a woman who marries outside of her own race (which in this dataset is predominantly Asian women—23% of the Chinese women in this sample are married to white men) are on average 2.5 cm taller than the average woman. This is after controlling for age, education and occupation.

I actually disagree with the authors’ conclusion that height is a determining factor in the low rates of interethnic marriage in the UK. It might be true that the distribution of heights matters, but my interpretation of this particular evidence is that it shows only that a man who is not white can to some degree compensate for his lack of whiteness by being taller. Or alternatively, a white woman may prefer to marry a white man but will consider marrying a non-white man if he is sufficiently taller than other men since she has preferences over both race and height and is willing to accept a trade-off.

This is similar to evidence that we discussed in a previous post that found that non-white men who hoped to attract white women on dating sites needed to earn a significantly higher income than white men.

I have another issue with this paper: Height at adulthood is not a function of ethnicity. In fact, on average men of different ethnicities will be the same height if they receive the same prenatal and early childhood nutrition. The Chinese men in this sample are not shorter on average (4.5 cm shorter in fact than white men) because they are ethnically Asian. They are shorter on average because they have, on average, come from a socio-economically disadvantaged background. No one is surprised by a result that suggests the men and women match with people with similar socio-economic characteristics to themselves regardless of race. Height is simply a proxy for that measure.

The problem with explaining low levels of interethnic marriage is that the low levels themselves make it nearly impossible to make statistically significant inferences. Out of 13,066 couples in this data set only 414 are interethnic with one partner being white (240 are a white woman married to a non-white man and 174 are white man married to a non-white woman). How can you say anything meaningful about the marriage decisions of the whole group based on the decisions of less than 3% of the sample? Bottom line – you can’t.

Belot, Michele and Jan Fidrmuc (2010). “Anthropometry of love: Height and gender asymmetries in interethnic marriages.” Economics and Human Biology Vol. 8: pp 361-372.