Simple Heuristics in the Real World
For more than 50 years, research on judgment and decision making has shown that people’s choices often deviate from “rational” behavior—at least in laboratory settings. In these experiments, people typically make decisions in stylized tasks where all possible outcomes and their probabilities are spelled out in advance. But real life rarely works that way. When making decisions like whether to move to another country, change careers, or disclose one’s sexual identity, people have to choose without knowing what the future will bring.
Over the course of evolution, and through collective and individual learning, humans have developed an adaptive mental toolbox for dealing with uncertainty in the real world. It is packed with simple but effective strategies known as heuristics, which require limited information and little mental effort. Despite—or perhaps because of—their simplicity, these mental shortcuts often outperform more complex deliberation. This happens when a heuristic is ecologically rational, meaning that there is a good fit between how a strategy leverages people’s cognitive processes and the statistical regularities of the world.
Our group tackles fundamental questions about human decision making: How do people make adaptive decisions, that is, decisions that keep pace with the constantly changing demands and opportunities of life? How do they select between different strategies, and under what conditions do these strategies work well? We address these questions both in the lab and in real-world settings. Technological advances such as GPS tracking, head-mounted cameras, computer simulations, and large language models (LLMs) enable us to study how people make decisions outside the lab. From transformative life decisions to daily food choices, our findings consistently show that people often use simple strategies that frequently perform as well as—or even better than—complex deliberation.
Heuristics for Transformative Life Decisions
Decisions like whether to emigrate, get divorced, or report a sexual assault can reshape the course of a person’s life. Yet surprisingly little is known about how people actually make these choices. In a series of studies spanning four continents (with assessments in Germany/United Kingdom, India, Nigeria, and the United States), we found that such transformative decisions are common experiences of adult life. Our research further showed that rather than carefully weighing and balancing all the factors involved, people tend to rely on simple strategies to make these big decisions—and that the outcomes are just as satisfying as those achieved through more complex, effortful deliberation. Strikingly, in Western countries, most people recommend complex strategies to others even though they don’t use them themselves—an “ideal–reality gap” that is absent elsewhere. This suggests that the pressure to be “rational” under conditions of deep uncertainty may reflect cultural beliefs rather than universal human behavior or best practice.
We are also investigating how individuals make extraordinary decisions under extreme conditions—acts of civic heroism such as refusing to follow military orders that target civilians, sheltering persecuted minorities, or testifying against powerful figures despite significant personal risk. By examining cases like Christine Blasey Ford’s Senate testimony and Alexei Navalny’s sustained defiance against Russian autocracy, we aim to understand not just why people act heroically, but how they make and sustain those decisions over time.
Heuristics for Foraging Decisions
Foraging—locating and extracting resources from the environment—is a fundamental behavior that is essential for survival across species. From bees hunting for nectar to humans gathering mushrooms or searching for information online, foragers must develop strategies to maximize resource intake relative to the time and effort spent. To study heuristic decision-making processes in a real-world foraging setting, we observed large groups of human foragers during ice-fishing competitions in Finland. Participants were equipped with GPS devices and head-mounted cameras, allowing us to track their every move. The results showed that ice-fishers use simple strategies to decide when to leave a spot. The longer they went without catching a fish, the more likely they were to move on. Conversely, catching a first fish made them less likely to leave. These dynamics are akin to those of the win-stay, lose-shift heuristic found in many other domains of reinforcement and animal learning. Simple strategies like these are thought to work well in unpredictable resource landscapes when compared to more complex strategies, such as calculating the mean number of fish caught per 30 minutes. Our findings confirm the value of heuristics in noisy, real-world decision-making contexts.
Heuristics for Climate Adaptation Decisions
Adapting to climate change requires tough decisions and involves substantial uncertainty. Individuals and organizations alike have to contend with numerous unknowns, including future weather patterns, climate impacts, societal developments, and the costs of different adaptation measures. Focusing on agriculture and forestry as two particularly exposed sectors, we brought together experts to discuss key adaptation decisions and strategies in focus groups. We found that practitioners tend to rely on experience and simple strategies like learning from others, diversifying, planning for worst-case scenarios, or adopting wait-and-see approaches when making adaptation decisions. These strategies do not require precise information,but may represent smart strategies for uncertain environments. In ongoing work, we are examining whether these simple strategies are sufficient to mitigate risks like income loss, and whether providing farmers with tailored climate predictions for the next 1–10 years could help them avoid doing too little or too much.
Heuristics for Healthier Food Choices
Choosing healthy food can feel overwhelming, with thousands of options to decide from during a weekly supermarket shop. Based on a detailed, large-scale analysis of the contemporary food environment, we aimed to identify simple and ecologically rational shopping heuristics that reliably result in healthier food choices. Using detailed nutrient information from over 7,600 food products, we ran computer simulations to test different strategies across thousands of simulated product comparisons. The results were striking: Strategies that focused on choosing foods higher in positive nutrients like protein or fiber didn’t just increase those specific nutrients—they consistently led to choices of products richer in other vitamins and minerals too. In contrast, strategies that focused solely on avoiding negative nutrients like sugar or salt reduced choices of those items but did little to improve overall nutritional quality. Other heuristics based on folk wisdom—choosing raw over processed, wholegrain over refined, and wild over domesticated foods—also led to healthier choices across multiple nutrients. These findings suggest that including information about beneficial nutrients on food labels and teaching consumers simple strategies that focus on positive nutrients can help to promote healthier eating habits.
References
- Claassen, M. A., Fuławka, K., Sultan, M., Kozyreva, A., & Hertwig, R. (2026). Heuristics for healthier food selection. OSF. https://doi.org/10.31234/osf.io/vdaup_v1
- Hechtlinger, S., Schulze, C., Leuker, C., & Hertwig, R. (2024). The psychology of life’s most important decisions. American Psychologist. Advance online publication. https://doi.org/10.1037/amp0001439
- Hechtlinger, S., Hertwig, R., & Schulze, C. (2025). How people make the most important decisions in their lives. OSF. https://doi.org/10.31234/osf.io/2sv8k_v1
- Rüsenberg, F., & Fleischhut, N. (2026). A behavioral change approach to understanding true demand for future climate information. OSF. https://doi.org/10.31235/osf.io/fynq6_v4
- Schakowski, A., Deffner, D., Kortet, R., Niemelä, P. T., Kavelaars, M. M., Monk, C. T., Pykälä, M., & Kurvers, R. H. J. M. (2026). High-precision tracking of human foragers reveals adaptive social information use in the wild. Science, 391, eady1055. https://doi.org/10.1126/science.ady1055