Thinking, Fast and Slow by Daniel Kahnemann.

Essentially we have two systems of thought. System 1 is the thinking you do automatically without realising you're thinking. It's the system that instantly finds the answer to the question "What is the capital of France?" System 2 is the thinking you do when you are asked something more complicated, or that you haven't considered before. It's the system that gets engaged when asked "what is the capital of Sudan?" It's hard at work when you're trying to add up the prices of items in your shopping basket, or when you're trying to count how many passes were involved in the buildup to a goal, or you're trying to figure out which one your mates is leaking your social media posts to the tabloids.

The book is mostly about how we are far more influenced by System 1 than we realise, to the point where even the way your System 2 operates is heavily dependent on the often nonsensical and irrational base assumptions generated by System 1 without us even realising. And how the consequences of that generate many, many more problems than we realise.

It's a really interesting read that explains all of the concepts quite well, with easy to understand psychology experiments, mini experiments he does in the text with the reader and practical examples of different biases in action.