Gigerenzer versus nudge


Jason Collins


July 29, 2014

Since I first came across it, I have been a fan of Gerd Gigerenzer’s work. But I have always been slightly perplexed by the effort he expends framing his work in opposition to behavioural science and “nudges”. Most behavioural science aficionados who are aware of Gigerenzer’s work are fans of it, and you can appreciate behavioural science and Gigerenzer without suffering from two conflicting ideas in your mind.

In a recent LSE lecture about his new book Risk Savvy: How to Make Good Decisions (which sits unread in my reading pile), Gigerenzer again has a few swipes at Daniel Kahneman and friends. The blurb for the podcast gives a taste. A set of coercive government interventions are listed, none of which are nudges, and it is suggested that we need risk savvy citizens who won’t be scared into surrendering their freedom. Slotted between these is the suggestion that some people see a need for “nudging”.

Gigerenzer does provide a different angle to the behavioural science agenda. His work has provided strong evidence for the accuracy of heuristics and shown that many of our so-called irrational decisions make sense from the perspective of the environment where they were designed (evolved). But his work doesn’t undermine the fact that many decisions are made outside of the environment where they originated – those fast, frugal and well-shaped heuristics have not stopped us getting fat, spending huge amounts on unused gym memberships and failing to save for retirement. Gigerenzer’s work provides depth to the behavioural analysis, rather than undermining it, and points to a richer set of potential solutions.

When Gigerenzer starts throwing around solutions, the difference between his approach and nudging becomes even hazier. In the LSE lecture he suggests that doctors be trained to present risks to patients in a certain way. That doesn’t seem much different from a typical nudge, although here it is the previously statistically-illiterate doctors presenting the information that nudges the patient behaviour.

One other interesting point in the lecture is when Gigerenzer speaks about the failure of breast cancer screening to cut deaths, and the presentation of results in deceptive ways designed to increase screening rates. He proposes presenting information by showing natural frequencies, which would likely reduce the rate of screening. But what of screening that doesn’t have deleterious side-effects for false positives of the same scale as breast cancer? Should they presented as Gigerenzer proposes, or in alternative ways more likely to induce screening? There has been no shortage of work in behavioural science designed to increase screening rates, particularly given the other biases and barriers that need to be overcome. I prefer Gigerenzer’s approach, but can see the arguments that would be mounted for the other side.

Otherwise, Gigerenzer’s speech channels Nassim Taleb on financial markets, before hinting at some of the very interesting work he is doing with the Bank of England. It’s generally worth a listen.