d) classification before calculus

In order to understand a complicated environment, people have developed prodigious capabilities for sorting and classifying information into well-organized systems. Classification makes life simpler and easier. Thus people became hardwired to stereotype people based on very small pieces of evidence, especially their looks and behaviours. Furthermore, the faster that you make decisions on these issues, the more likely you are to survive. Even comprehensive training cannot fully eliminate irrational and simplifying biases.

Thus people sub-consciously sort out others into in-groups and out-groups, such as winners and losers, by appearances and behaviours. This quick stereotyping can lead to incorrect classification, ie everyone is too busy labeling others as outsiders and dismissing them in the process.