No Two Alike

Good Books: (via Emergic) Here is how Publisher's Weekly (via Amazon.com) summarizes the book, No Two Alike:
Why do identical twins who grow up together differ in personality? Harris attempts to solve that mystery. Her initial thesis in The Nurture Assumption: Why Children Turn Out the Way They Do is replaced here with a stronger, more detailed one based on evolutionary psychology. Reading this book is akin to working your way through a mystery novel complete with periodic references to Sherlock Holmes. And Harris has a knack for interspersing scientific and research-laden text with personal anecdotes. Initially, she refutes five red herring theories of personality differences, including differences in environment and gene-environment interactions. Eventually, Harris presents her own theory, starting from modular notions of the brain (as Steven Pinker puts it, "the mind is not a single organ but a system of organs"). Harris offers a three-systems theory of personality: there's the relationship system, the socialization system and the status system. And while she admits her theory of personality isn't simple, it is thought provoking. Harris ties up the loose ends of the new theory, showing how the development of the three systems creates personality.

This is what Scientific American wrote (via Amazon.com):
Where does adult personality come from? Why are we all different? These are the questions energizing Judith Rich Harris's new book. Harris then develops a complex scheme based on "the modular mind," a framework set forth by Harvard University evolutionary psychologist Steven Pinker and others. (Harris herself has no doctorate and is housebound by systemic sclerosis and lupus, two autoimmune disorders.) She describes three modules: the relationship system, the socialization system and the status system, and explains how each contributes its part to making us who we are. The relationship system starts in the cradle as infants study and learn the faces and voices of the people around them, collecting information that helps form personality. The socialization system adapts people to their culture. The status system takes all the information collected during childhood and adolescence and shapes and modifies our personalities in accord with our environments.

Harris's last chapter lays out her theory in tabular form, explaining how each module interacts with the others to produce our distinct personalities. It is lavishly footnoted, like the rest of the book, shoring up her strategy of pointing out the failings of other models and then proposing her own. Her goal, she writes, is to explain the variations in personality that cannot be attributed to variations in people's genes.

It's amazing when you try to understand the link between human nature and individuality + the complex mental infrastructure + the distinguishing characteristics. No Two Alike is a fascinating book because it's a story about us and the people around us.