448. The Downside of Disgust

Episode Summary

Executive Summary: This Freakonomics Radio episode examines disgust as an evolved, highly variable emotion that helps protect us from disease yet can also block beneficial behaviors. Through psychologists Paul Rozin and Val Curtis, economist Sandro Ambuehl, and Kraft Heinz’s Emily Kimmons, it explores how disgust can be reduced or leveraged to encourage handwashing, insect consumption, and recycled water acceptance, while showing how habits, incentives, and exposure reshape what people find acceptable.

Main Topics: Disgust as an evolved disease-avoidance system: Paul Rozin and Val Curtis frame disgust as an adaptation that originally helped humans avoid pathogens in food, bodily contamination, and other disease-linked threats. The episode distinguishes physical, social, and moral disgust while emphasizing cross-cultural variation. The six categories and expressions of disgust: Rozin outlines six disgust domains: hygiene, animals/insects, sex, atypical appearance, infection/lesions, and spoiled food. The episode also highlights bodily expressions like the disgust face and universal-sounding vocalizations such as "blech" or "ugh." Using disgust to change health behavior: Curtis describes successful public-health campaigns that used disgust rather than disease facts to motivate handwashing, including a Ghana intervention that more than doubled handwashing rates and had lasting effects. Reducing disgust to adopt useful innovations: Rozin argues that disgust can obstruct acceptance of recycled water and insect protein despite environmental and nutritional benefits. The episode presents exposure and familiarization as ways to lower disgust barriers. Economics, incentives, and self-persuasion: Sandro Ambuehl’s experiments test whether higher payments make people more willing to eat insects and whether incentives improve or distort decision-making. His findings suggest bigger incentives increase information-seeking and self-persuasion, which economists view as rational. Commercializing insect-based foods: Kraft Heinz’s Emily Kimmons discusses how food companies evaluate new products and why insects face a major "ick factor." She emphasizes hidden forms, familiar pairings, exotic framing, and gradual introduction as strategies for consumer acceptance. Norm change over time: The episode closes by showing that food and social taboos change historically, from squirrels to life insurance. This supports the idea that today’s disgust reactions—like insects—may weaken as tastes, language, and market forms evolve.

Key Arguments: Disgust likely evolved to avoid parasites and pathogens, making it adaptive for survival but sometimes overly restrictive in modern life. Not all disgust is universal: feces and disease-linked substances are broadly repellent, but many food and social disgusts vary by culture and person. Disgust can be used strategically in public health to promote hygiene when framed around contamination and consequences rather than abstract risk. The same emotion that protects health can block beneficial innovations such as recycled water and insect protein, creating environmental and economic costs. Repeated exposure reduces disgust; people can learn to tolerate or even like initially off-putting foods after sufficient experience. Higher monetary incentives can change how people process repugnant choices by encouraging them to focus on upside information and reduce the chance of rejecting a beneficial option by mistake. For consumer products, successful insect adoption likely requires hiding the insect, blending it with familiar flavors, using appealing language, and starting with adventurous niches before mass markets.

Data Points: Freakonomics Radio archive size: More than 10 years and 400 episodes - Dubner announces the archive is now free on every podcast app. Number of disgust categories: 6 - Paul Rozin lists hygiene, animals/insects, sex, atypical appearance, infected lesions, and spoiled food. Duck? no—disgust scale example: Top 20% least disgusted - Rozin says he personally falls in the least-disgusted fifth of people. Handwashing campaign impact: More than doubled - Curtis says the Ghana handwashing rates increased substantially after the disgust-based ad campaign. Insect fragments allowed in chocolate: Up to 60 fragments per 100 grams - Val Curtis cites FDA tolerance standards for chocolate products. Average insect fragments in a chocolate bar: 8 fragments - Curtis notes the routine, unintended ingestion of insects in common foods. Consumer reactions in Ambuehl experiment: Around 1/3 at $3 vs nearly 60% at $30 - Students were more likely to agree to eat 5 mealworms when offered a higher payment. Video choice effect at $30: More than 70% - With the higher payment, viewing a pro-insect video further increased willingness to eat mealworms. Cost to induce some students to eat a whole scorpion: $200 to $300 - Ambuehl describes a separate experiment involving large scorpions. EU food-safety ruling: Mealworms declared safe for human consumption - The episode notes a regulatory step that could support scaling insect foods. Val Curtis age at death: 62 - Dubner reports Curtis died of cancer before the episode’s release. UK cancer-death estimate linked to pandemic strain: 35,000 - Curtis argued pandemic and austerity delays could lead to extra cancer deaths in the UK.

Pivotal Quotes: "there are enormous variations in disgust" — Paul Rozin: Used to explain cross-cultural and individual differences in disgust sensitivity. "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 why disgust appears evolutionarily adaptive. "The biggest concern is the ick factor" — Emily Kimmons: Kimmons summarizes the main consumer barrier to insect-based foods.

Implications: Disgust is malleable, so public health, food companies, and sustainability advocates can reshape acceptance through exposure, framing, and product design. Insects and recycled water may become more viable if they can be made familiar, safe, and culturally legible.