EXTRA: The Downside of Disgust (Update)

Episode Summary

Executive Summary: The episode examines disgust as an evolved protection against pathogens that also shapes moral judgment, food choices, and behavior. Through psychologists Paul Rozin and Val Curtis, and economist Sandro Ambuehl, it argues disgust is highly variable and manipulable: it can be increased to improve hygiene, reduced to encourage recycling, water reuse, and insect consumption, and altered by incentives and repeated exposure.

Main Topics: Disgust as an evolutionary defense: Val Curtis and Paul Rozin explain disgust as a brain-based system that originally evolved to avoid parasites and pathogens, especially in food and hygiene contexts. Different kinds of disgust: The episode distinguishes six categories of disgust: hygiene, animals/insects, sex, atypical appearance, injury/disease, and spoiled food; it also covers facial and verbal disgust expressions. Moral and social disgust: The hosts explore how disgust extends beyond food into moral judgments, and whether calling something 'disgusting' is literal bodily disgust or metaphorical condemnation. Using disgust to change behavior: The episode shows disgust can be leveraged in public health campaigns, especially handwashing, where graphic messaging successfully changed behavior. Reducing disgust for environmental and economic gains: Rozin argues that lowering disgust could help normalize recycled water, insect protein, and other beneficial but initially off-putting practices. Incentives, exposure, and insect eating: Economist Sandro Ambuehl tests whether money and information change people’s willingness to eat insects, while also highlighting the role of familiarity in reducing disgust. Industry feasibility and cultural change: A Kraft Heinz consumer-science executive discusses how major food firms might hide or blend insects into familiar products, but notes the 'ick factor' remains a major obstacle.

Key Arguments: Disgust likely began as a pathogen-avoidance adaptation, which is why feces, vomit, rotting food, and diseased bodies are near-universal disgust triggers. Disgust varies greatly across individuals and cultures; outside a few basics, many foods and practices are deemed disgusting largely through learned associations. The same emotion can be strategically used: disgust-based handwashing campaigns can meaningfully improve public health behavior. Disgust can also block socially beneficial innovation, such as wastewater recycling and insect-based protein, even when those options are safe and efficient. Economic incentives change how people process repugnant choices: higher pay makes people more open to favorable information and more willing to override disgust. Repeated exposure reduces disgust over time, suggesting that tasting or handling something unfamiliar can make it acceptable. For insects to become mainstream, they likely need to be processed into familiar forms, taste good, and be framed as adventurous rather than repulsive. Large food companies could plausibly enter the insect market, but consumer acceptance in North America and Europe would require careful product design and branding.

Data Points: Types of disgust: 6 - Paul Rozin's framework: hygiene, animals/insects, sex, atypical appearance, infected wounds/lesions, and spoiled food. Rates of handwashing increase: More than doubled - Val Curtis describes a disgust-based handwashing campaign in Ghana that significantly raised handwashing rates. Campaign durability: Still high several years later - Handwashing gains from the Ghana campaign persisted over time. Insect-eating prevalence: More than 1 billion people - Used to show insect eating is already normal in many parts of the world. FDA contamination allowance in chocolate: Up to 60 fragments per 100 grams - Val Curtis notes insect fragments are allowed in chocolate bars under U.S. standards. Insect fragments in a chocolate bar: Average of 8 fragments - The transcript cites typical chocolate-bar contamination levels. Scorpion compensation: About $200 to $300 - Sandro Ambuehl says this is the amount needed to get some college students to eat a whole scorpion. Low-payment insect trial: $3 - In one experiment, students could earn $3 for eating five mealworms. High-payment insect trial: $30 - In the comparable experiment, students could earn $30 for eating five mealworms. Mealworm acceptance at low pay: Around one-third - About a third of subjects accepted five mealworms for $3 without needing a video. Mealworm acceptance at high pay: Nearly 60% without video; more than 70% with video - Higher payment increased willingness and openness to positive information. EU food safety milestone: 2021 - The European Union's Food Safety Authority ruled mealworms safe for human consumption. EU market approval: 2023 - Two years later, the EU approved powdered and dried insect proteins for human consumption. Kraft Heinz feasibility rating: 5/10 for the general food world; 7/10 for Kraft Heinz - Emily Kimmons estimates insect products are possible but harder for a mainstream U.S. brand. Kraft Heinz tasting limit: 2 hours - Professional tasters work only two hours to prevent sensory fatigue. Kraft Heinz taste-test load: 10 to 12 macaroni and cheeses - Kimmons says tasters can evaluate only about this many samples before they all start to taste the same.

Pivotal Quotes: "There is a very obvious pattern here, that the things that everyone around the world seemed to regard as disgusting, they were all things that might harbor parasites and pathogens and so might make us sick." — Val Curtis: Curtis explains the evolutionary logic behind disgust. "When in doubt, cover it with chocolate." — Stephen Dubner: A lighthearted summary of how to make insect foods more palatable. "I mean, judging from my own reaction and the reaction of many people I have seen, I do think it's going to be very, very hard to convince even a sizable minority of the population to consume insects on a regular basis." — Sandro Ambuehl: Ambuehl on the difficulty of mainstreaming insect eating.

Implications: Disgust is not fixed; it can be engineered, softened, or redirected. That means public-health, food, and environmental campaigns can succeed by working with human psychology instead of against it, especially through familiar formats, repeated exposure, and smart incentives.