Summary:
- The bell curve, or normal distribution, is a mathematical model that describes how many things in nature and society are distributed, from IQ scores to the heights of people.
- The bell curve arises from the central limit theorem, which states that when many independent random variables are added together, the result will tend to follow a normal distribution.
- This mathematical property explains why bell curves are so prevalent in the world, from the distribution of heights and weights to the spread of test scores and the occurrence of natural phenomena like radioactive decay.