I really don’t care why evolution happened

I care about how things are now

The point of science (I include economics within this) is to help us make better decisions now. We do it to improve our lives. The questions we ask should be with an aim to doing things better, here and now. It’s a fun exercise to speculate as to why we, or our cultures and institutions, evolved to be the way they are. Papers based on this are often incredibly cool. One which stands out is “On the Origin of Gender Roles: Women and the Plough”. Alesina, Giuliano, and Nunn find that places which are more geographically suitable to plow-based agriculture have fewer women in the workforce, and more patriarchal attitudes, long after the plow has ceased being relevant. Importantly, these attitudes are held even after people immigrate to other places, which may have more progressive attitudes. It’s really exciting! It’s objectively cool! It’s like knowing about the existence of galaxies far away, or how many species of krill there are under the polar ice cap. 

 But on the other hand, such exercises are at all useful. How are we supposed to improve the world with this knowledge? They are not good science, if pursued for their own sake. It is telling a fundamentally unfalsifiable story, because you will never be able to test the story a second time. Whether it is actually applicable to other circumstances is unknowable. They suffer from a really bad multiple comparisons problem. There are thousands, if not millions, of things in the world today which could plausibly have an impact on the future. We cannot plausibly predict what will still matter in 300 years. It is far easier to look backwards than forwards, and you can look and look and look again until you find something significant. 

Above all, they are concerned with the impact of circumstances which are highly unlikely to recur. Are we going to be returning to traditional agriculture again? Are we going to be returning to the middle ages, pogroms and all? Is Peru likely to be colonized by the Spanish again, and the native tribes placed in different forced-labor systems? No? Then why does knowing the effects matter? Are we able to make forward-looking predictions, or are we telling just-so stories?

One errs by thinking of these studies as really being about the cause itself. What is useful is using some exogenous variation in the past to measure the impact of something which exists in the present day. I have discussed the Nathan Nunn series of papers on the long-run impacts of slavery on this blog before; while on one level, they are about the effects of slavery, that’s not what they’re really about. They’re about the effects of trust on economic development. We don’t have the slave trade now; I hope that we have progressed to such a point that it will never recur. We do have distrust, and we do have different levels of trust between countries. That is of immense relevance to public policy now. AJR 2001 is another example of a paper on one hand about persistence, but on the other hand about something far more useful. It is not interested in the effect of different disease environments per se on development, but rather on the effect of institutions on development – disease environment is just a way to get variation!  The “Women and the Plough” paper can be rescued on the grounds that it’s really about the stickiness of cultural attitudes, and that we should look first at changing other things. The important thing is not simply asking “why”, though – it’s asking, “why, and what does that imply?” 

So I say this all by way of prelude, to a more controversial point. There are differences in intelligence between populations. They may be evolved differences – I am not competent to say – but to be honest, I do not give a fuck why populations evolved differently. Are we going to be back on the savannah? Are we going to be in hunter-gatherer bands? Does this have the slightest relevance to how to improve the world and reduce poverty now? So please, don’t speculate on why things happen to be how they are, unless it gives us knowledge of how to change it. “Redo thousands of years of evolution” is not reasonable. 

And what’s more, we as government subsidized scientists have a moral duty to separate out what we think is cool from what we should do. We are employed to find knowledge which benefits the world. We are to find what would be found if knowledge were perfectly appropriable. We should ask ourselves of our research, “will this make people better? Or am I doing it for me?” And if it is the latter, we should stop doing it.