I agree. There was however a nice paper showing relationships to trader performance and testosterone/cortisol ratios last year, and there have been studies showing testosterone:finger length correlations as well. Obviously more work is needed.
..and most posts on this story seem to assume that the paper claims a correlation between digit ratio and performance. It doesn't - assuming that there is, in fact, a correlation between digit ratio and testosterone levels, it probably implies nothing more than that high testosterone levels are necessary to impress the decision-makers in trading companies.
It's an interesting correlation, but it pretty much follows from
high testosterone levels -> low digit ratio
and
high testosterone levels -> high trader salary
It makes sense that small differences in some personal characteristic leads to large differences between the compensation of traders. The interesting question is whether slightly higher testosterone levels cause ten times better performance over time (or even enough of a performance improvement to justify a ten times greater salary). This seems like a ludicrous claim. But it's really funny if this is, in fact, what the market implicitly expects from its traders.
