I like to refer to a great book and MIT Press Reader article from Gregory Murphy on the Psychology of Categories, an in-depth analysis of how humanity’s compulsion to categorize affects every aspect of our lived experience.
“Every category is a simplification to some degree; it throws away information about the thing.”
The minute we are born—sometimes even before—we are categorized.
From there, classifications dog our every step: to school, work, the doctor’s office, and even the grave. Despite the vast diversity and individuality in every life, we seek patterns, organization, and control.
In Categories We Live By, Gregory L. Murphy considers the categories we create to manage life’s sprawling diversity. Analyzing everything from bureaucracy’s innumerable categorizations to the minutiae of language, this book reveals how these categories are imposed on us and how that imposition affects our everyday lives.
We often feel that once we determine the thing’s category, then all questions will be answered about it.
Categories We Live By explores categorization in two parts.
In part one, Murphy introduces the groundwork of categories—how they are created by experts, imperfectly captured by language, and employed by rules.
Part two provides a number of case studies. Ranging from trivial categories such as parking regulations and peanut butter to critical issues such as race and mortality, Murphy demonstrates how this need to classify pervades everything.
Finally, this comprehensive analysis demonstrates ways that we can cope with categorical disagreements and make categories more useful to our society.
Language is an imperfect clue to what categories we have.
… many scientific categories have the same problems as our everyday categories do.
The case of Pluto is one that many people know. During the debate over whether Pluto is a planet, it came to light that there was no definition of what a planet is. Oops!
And I discovered, to my dismay, that there is little agreement in biology over how to determine what a species is. The problem, I argue, is not in science or in our human institutions, but in the world, which is extraordinarily complex.
There are many different valid ways of dividing up the entities in the world, and we have to figure out which ones are useful to us.
That’s why understanding how and why we make categories is itself an important goal.
The world doesn’t give us categories for free — we have to make them ourselves.

