Many of crises are considered to be predictable. It may be because human beings have a tendency to underestimate the magnitudes of risks. This article investigates the phenomenon of underestimation by dividing risks into two types: Risk 1 and Risk 2. A typical Risk 1 is a predator. Risk 2 contains both natural disasters and most risks in the modern society. System 1 of human cognition is adjusted to Risk 1, and System 2 is not able to make an accurate assessment of Risk 2 yet. Therefore, both systems are inclined to underestimate the magnitude of Risk 2.