Intuitive way to understand Gaussian Bell curve(normal distribution)

Introduction

Laymen explanation

If you are associated to things at large(for example, human population) , then you will definitely understand the importance of understanding mass behaviour. You can use this to create a policy which will be acceptable to the population. Now the question is to know right tool. Another question is where this tool will be applicable and where it will not be? If not considered, then we will get wrong result. This article tries to analyse one such tool, bell curve.

Technical explanation

In probability theory, the normal (or Gaussian) distribution is a very common continuous probability distribution. Normal distributions are important in statistics and are often used in the natural and social sciencesto represent real-valued random variables whose distributions are not known.

Simpler way to understand why it works

There are certain mathematical foundation for this known as central limit theorem. However, for non-mathematician there is a simpler way to understand. I am explaining this simple reason here.

Try to think what bell signifies in this curve? Notice that bell signifies that majority of population are close to mean. In other words, majority of population has common traits. Now think that what is causing it? Here is the answer. Population is common since they copy each other. Isn't it? Take the example of human population. By nature, genes are transferred using copy (remember not exact copy). So, newborns are similar. As newborns grow, they copy traits from each other. So, this copying business ensure that they are similar.

So, where we should not apply this curve?

It depends on your problem statement. If you are analysing contribution of employee in a company, you should decide based on company vision. If company is thriving for innovation, then its employees will tend not to copy many things. In such company, your reward system based on bell curve will be seen unfair.

Similarly, in an academic institution thriving for creativity should not use this curve for giving marks to their students.

Where we should use it then?

This curve is in fact used heavily and so, answer might be obvious. This curve should be used to understand current human population. For example, if we want to transform existing population of a country to entrepreneur ship culture, then we can use this. This curve will indicate the factors which needs to be considered to break the copying behaviour of the population.

Reference

Personal thought

https://en.wikipedia.org/wiki/Normal_distribution

https://www.investopedia.com/terms/b/bell-curve.asp