System 1 and System 2

Mudassir Azeemi
2 min readMay 29, 2023
Photo by Jukan Tateisi on Unsplash

Summary of “Thinking, Fast and Slow”.

“Thinking, Fast and Slow” by Daniel Kahneman explores the intricacies of decision making and cognitive biases. Kahneman, a Nobel laureate in Economics, intricately dissects the dual-process model of the human brain, dividing our cognitive functioning into two systems, aptly named System 1 and System 2.

System 1 operates automatically and quickly, with little or no conscious effort. It’s this system that performs simple computations, recognizes danger, and makes snap judgments. It’s our intuitive, gut-reaction system that operates based on patterns and past experiences. It’s remarkably efficient but susceptible to errors and biases, as it tends to jump to conclusions.

On the other hand, System 2 is slow, effortful, and more logical. It’s responsible for deliberate thinking, complex calculations, and decision-making. It requires mental effort and concentration. While System 2 is more reliable and less prone to error, it’s also lazy by nature and often defaults to the quick judgments of System 1 unless prompted to engage.

Kahneman suggests that the interaction and occasional conflict between these two systems influence our decisions and judgments. Our mind tends to over-rely on System 1, leading to cognitive biases that can affect our decision-making capabilities. Some of the key biases Kahneman discusses include confirmation bias (the tendency to favor information that confirms our existing beliefs), availability bias (relying on immediate examples that come to mind when evaluating a specific topic), and the anchoring effect (the human tendency to rely too heavily on the first piece of information encountered).

One of the most impactful concepts Kahneman introduces is “prospect theory,” which asserts that people make decisions based on the potential value of losses and gains, not the final outcome, and that people weigh losses more heavily than gains. This challenges the traditional economic theory of the “rational actor.”

Throughout the book, Kahneman invites readers to introspect and become aware of their cognitive biases, urging them to engage System 2 more frequently to combat these biases and improve their decision-making.

In essence, “Thinking, Fast and Slow” is a call to mindful thinking. It encourages the reader to become conscious of their thought processes and to understand that instinctive reactions, while useful, may not always lead to the best decisions. By understanding the workings of System 1 and System 2, individuals can better navigate their cognitive biases and make more informed decisions.



Mudassir Azeemi

Finding patterns in chaos. Pioneer of Urdu language on Apple devices! UX/UI Instructor | Speaker | Design Governance Head at Ring Central | Curious