I argue that “Darwinian algorithms,” to use the term from Leda Cosmides, can be represented by an adaptive toolbox of efficient heuristics that enable us to think, feel, and cooperate. The human brain evolved to deal with situations of deep uncertainty, not with toy problems of calculable risk, which have been the stock-in-trade of past decision theory. In an uncertain world, content-blind logical rationality, such as following consistency axioms and maximizing expected utility, is typically intractable. Here, simple rules—known as fast-and-frugal heuristics—can lead to efficient decisions for humans and other animals. These heuristics can be used both unconsciously (i.e., intuitively) or consciously; contrary to what current dual-process theories assume, the process remains the same.

My talk presents the study of the repertoire of heuristics available to individuals, cultures, and species, and examines their ecological rationality, namely how these heuristics leverage the structure of the environment to achieve effective outcomes. The concept of ecological rationality helps to understand that (i) rationality is not a simple property of mental rules such as Bayes’ rule but is instead a binary (adaptive) property of the match of a rule to an environment and (ii) many so-called cognitive biases are signs of content-dependent intelligent thinking rather than of irrationality. By replacing logical rationality with ecological rationality, we can overcome the misconception of heuristics as biases. Combining ecological rationality with evolutionary theory opens a future window to a better understanding of the nature of the adaptive mind.

Gerd Gigerenzer is Director of the Harding Center for Risk Literacy at the University of Potsdam and Director emeritus at the Max Planck Institute for Human Development in Berlin. He was awarded honorary doctorates from the University of Basel and the Open University of the Netherlands, and is Batten Fellow at the Darden Business School, University of Virginia. His award-winning popular books Calculated Risks, Gut Feelings, and Risk Savvy have been translated into 21 languages.

• Date: Friday September 19th, 2025,  9:30 am - 10:30 am
• Location: Stadscampus UAntwerpen, Promotiezaal van de Grauwzusters( Lange St-Annastraat 7, 2000 Antwerp)

Participation is free, but online registration is mandatory. 

This lecture is part of the ​Annual Conference of the Cognition and Behavior Evolution Network​ that takes place from 18 - 19 September 2025, organised by Charlotte De Backer & Carolyn Declerck. 

Want to know more? Download the ​full conference programme​, and/or contact prof. dr. Charlotte De Backer.