Matt Ridley’s The Rational Optimist


Jason Collins


April 16, 2012

A common recommendation for an addition to my evolution and economics reading list is Matt Ridley’s The Rational Optimist: How Prosperity Evolves. These thoughts are designed, in part, to explain why I don’t plan to add it.

The core theme of The Rational Optimist is that exchange is the major driver of human progress. Exchange allows specialisation and division of labour, which results in people doing the tasks they do best.

Exhange also increases innovation, for which, as Ridley points out, there are cumulative returns. He captures this concept in the phrase “ideas having sex”. Ideas can be combined into new ideas, further increasing their value.

I agree with Ridley’s general argument concerning the importance of exchange and innovation, but when Ridley puts it in the context of evolution, he creates an implication of progress that evolution does not have. For example, Ridley writes:

I have tried to show that, just as sex made biological evolution cumulative, so exchange made cultural evolution cumulative and intelligence collective, and that there is therefore an inexorable tide in the affairs of men and women discernible beneath the chaos of their actions. A flood tide, not an ebb tide.

Through the book, Ridley generally takes this tide to be one way unless government gets in the way. But while biological evolution has a tendency towards greater complexity, there are extinctions and crashes. Ridley turns a general tendency into an iron law.

This habit manifests itself through the book, as noted in an excellent review by Bill Easterly. Suppositions and thought experiments often become statements of fact in the space of a couple of pages. I suspect many of them are right, but some arguments are a stretch.

Part of the reason why Ridley takes the combination and accumulation of ideas to be a forward march is that the ideas which are the focus of Ridley’s discussion are those which drive technological progress. But ideas also appear as religions, urban myths, political philosophies and conspiracies. So when he writes of the Darwinian selection that occurs between ideas, he does not consider whether the idea will be good for the hosts. It may generally be, but again there is no iron law that this is the case.

Ridley also skims over human evolution, attributing change over the last thirty thousand years to cultural evolution. While he occasionally contemplates the role of more recent evolution, such as his suggestion that humans have evolved to have high oxytocin receptivity associated with trade, his exploration in that area sells it short. Willingness to trade and foresight would have been greatly rewarded in recent times.

Despite my discomfort with the direction that Ridley places on evolution, I like The Rational Optimist. It is an entertaining read, and despite the selective use of facts and arguments that come with an advocacy book, it places a light on human progress and the benefits to trade that most people don’t appreciate. I also believe that Ridley’s optimism concerning human wellbeing is well placed over the timeframes in which we can predict. In 2050, despite climate change, the people of the world will be richer, live longer, have better health, have access to more goods and services and experience less extreme poverty, on average, than they do now. Over the last 200 years, technological progress has been very good to us.

Despite Ridley’s claims that he is no Panglossian, he sometimes veers in that direction. Worried about overpopulation? Don’t worry, fertility is falling. Worried about underpopulation and an ageing population? Don’t worry, fertility is going back up again. His approach to the ecological effects of climate change reflect a similar tendency.

I would have liked Ridley to discuss in more detail how he sees his expectation of increasing wilderness areas and protection for ecosystems coming to fruition. He argues that organic farming is land intensive and notes that by adopting more intensive forms of agriculture, we could return land to wilderness. If organic farming were as inefficient in its use of space as Ridley suggests, and was demanded by an increasingly rich population, what would Ridley propose we do about it? Ban it? Many of Ridley’s targets for criticism are the product of the choices of rich people, and there are going to be more rich people.

Ultimately, I also take Ridley’s plea for optimism with a grain of salt. Contrast Ridley’s plea for optimism to Julian Simon’s suggestion that it is worry that actually delivers the benefits.

I have never said that we don’t need to worry about anything. We need to worry about everything, in the same sense that you had to worry whether you’d get here on time, whether there’ll be enough food in your kitchen for next week, and so on. The world needs the best effort of all of us. I’m saying that the result of all this worry – and of your constructive work, of your throwing your life into trying to do good things for the world and for other people – is that on balance you will create more than you will use in your lifetime, and you will leave the world a little better than before, on average.

If there is no iron law that everything will get better, a bit of worry is useful to increase the chance it will.

Overall, Ridley’s case is strongest on the economics. Specialisation and trade have played a massive part in human progress. More people mean more ideas, so larger populations have generated greater technological progress. But as Ridley argued in his book The Red Queen: Sex and the Evolution of Human Nature (a book I should add to my recommended reading list), evolution is not about constant progress. Rather, it is about running as fast as you can to avoid falling behind.