LessWrong's 'Map and Territory' exposes 5 cognitive biases that sabotage rationality

manueldelrio's LessWrong post, 'Map and Territory, Predictably Wrong (2)', continues a series on rationality and cognitive biases, drawing directly from Eliezer Yudkowsky's classic sequence. The post is a compact 3-minute read that walks through five distinct mental errors. First, it explains the conjunction fallacy: people often rate 'A and B' as more probable than 'A' alone, because added details make scenarios sound more plausible. The mathematical truth is that adding an 'and' can only lower probability, so readers are told to treat every conjunction with suspicion.

The second major topic is the planning fallacy, where our 'realistic' estimates mirror our most optimistic scenarios. The fix is an 'outside view'—comparing with similar past projects rather than getting lost in the current details. The post also covers the illusion of transparency (assuming your meaning is obvious to others), the curse of knowledge, and the problem of short inferential distances: in complex technical fields, we wrongly expect explanations to be graspable in a few steps. It ends by celebrating reflective rationality—our ability to examine and correct our own thinking processes, a uniquely human skill that makes all other debiasing possible.