Extract from 'The downside of disgust', Freakonomics Radio, Ep. 448

Freakonomics: I got to wondering whether the field of economics had anything worthwhile to say about disgust.

Sandro Ambühl: Economists don’t usually think about disgust.

That’s Sandro Ambuehl, an economist at the University of Zurich.

They think, if anything, about moral repugnance, because that puts limits on what can be traded in markets.

Repugnance would seem at least moderately linked to disgust, as it often centers around the human body.

For instance, it limits how much you can pay people to participate in medical trials or surrogate motherhood or human-egg donation and so forth. There’s limits on the incentives that you can provide for these kind of transactions. But is it true that incentives lead to worse decision-making? We have all these laws that are based on this hunch.

Laws against, for instance, compensating kidney donors. Or even offering compensation for breast milk.

It’s something that is empirically testable but hasn’t been empirically tested. So, that’s the main question that I want answered.

He set out to answer this question with a set of experiments. Even though Ambuehl says he was thinking about repugnance, he plainly understands disgust. Because he built his experiments around the eating of insects.

Yeah, that’s right.

He used college students, of course, as his research subjects.

The way the experiment works is, people make decisions in five rounds, and each round was associated with one species of insect.

He used mealworms and silkworm pupae and a variety of crickets.

House crickets, field crickets, and maybe the most disgusting ones are mole crickets. They are really nasty. In the beginning, I brought buckets and tissues. Because I was afraid that somebody might throw up.

It turns out that didn’t happen. Maybe because the people who knew they’d throw up were the ones who opted out of eating insects during the experiment. Because you were given that choice. In one experiment, for instance:

There’s two groups of people. If you’re in the first group, you learn that you’re gonna be given $3 if you decide to eat five mealworms. If you’re in the second group, you’ll learn that you’re gonna be given $30 if you agree to eat five mealworms. Now, after you learn how much money you are given, but before you make a decision, you can choose between two videos to watch, to inform yourself about what eating these things is going to be like. One video is called “Why You May Want to Eat Insects.” The other video is called “Why You May Not Want to Eat Insects.”

Ambuehl wanted to measure how both financial and informational incentives affected the decisions his research subjects made. There was a separate experiment to see how much he’d have to pay students to eat a whole scorpion.

So, these are really large scorpions that are as big as your hand. And it takes about $200 to $300 to make college students eat those, or to make some college students eat those.

In the interest of scientific equity, Ambuehl ate one of these scorpions himself.

Take a plastic spoon, put a small shrimp on it, season it with some motor oil, and then eat everything, including the spoon. That’s about what eating a scorpion is like.

What was Ambuehl trying to learn with this kind of experiment?

I wanted to know if I offer incentives to somebody, what do I do with their quality of decision-making?

This goes back to the idea of whether financial incentives might skew someone’s judgment toward selling their kidneys or eggs.

What I’m interested in is whether, if I pay people a larger amount of money, are they going to be more interested in watching the positive video than the negative video? And it turns out the answer to that question is yes.

In other words, the bigger incentive increases their appetite to persuade themselves that what they’re about to do is a good idea. Among the research subjects who were offered just $3 to eat the insects, around a third decided to do it, even without access to a video. Among the subjects who were offered $30, nearly 60 percent decided to eat the insects without video access, and more than 70 percent after watching the video about why eating insects is a good idea. So, what did this tell Ambuehl?

This result looks like incentives are causing bad decisions.

But if you’re an economist, as Ambuehl is, these are in fact good decisions. How so?

If I offer you very little for doing something you might not like — well, what you want to make sure is that you don’t say yes by mistake. You’re okay with saying no because there’s not much to gain. Now, if I offer you a lot of money, saying no by mistake all of a sudden is quite expensive. And so, you become more interested in learning about the upsides rather than the downsides of the transaction.

Now, how does this apply to Paul Rozin’s mission of getting people to eat more insects?

Rozin: Well, economists, of course, love financial incentives, but there’s a problem. If you pay people to eat insects, they’re less likely to engage with it after you remove the payment. The fact that they’re being bribed to eat something may actually block getting to like it. Now, we don’t know how people get to like things. We still don’t know that. But it does seem that imposed incentives may block it — sometimes, but on other occasions they may not.

In other words, as all researchers like to say always: “further research is needed.” But with the incentives unclear, where does that leave you if your mission is to get people to eat more insects?

Ambühl: In psychology, there’s this phenomenon called the mere-exposure effect. And what it says is just, as you are exposed to something over longer and longer time periods, you start liking it.

And Ambuehl had noticed, as he ran his insect experiments, that the mere-exposure effect was working on him.

As I was sitting there for a large number of hours putting insects into little plastic containers, I started snacking voluntarily on the house crickets.