The Birth of the Mind: How a Tiny Number of Genes Creates the Complexities of Human Thought

"If you are among those still arguing the "nature versus nurture" debate has been resolved, visit an English Lit class. The humanities continue skirting the notion that genes play a role in our mental life. It challenges our ideal of "free will". Marcus, in this matchless survey, argues that "what's good for the body is good for the mind". And few dispute that genes build bodies. The mind, like the body, has deep evolutionary roots. Even the simple organisms inhabiting the planet with us today show how brains develop. Increased complexity of body is reflected in brain structure. And the mind, he reminds us, resides in the brain.

Marcus explains his notion with a wealth of research, most of it very recent. He explains how similar our brain structure is to that of other animals and what that implies for behaviour. The mechanism of building brains is common to all animal life, even when the final product varies. Genes transmit signals - "recipes" - of structure and function for all parts of the body. Brains, he continually reminds us, are not that different from livers. Neurons proceed from points of origin, finding appropriate areas to reside and assume functional duties. From origin to operation they show flexibility and adaptability. In this, Marcus argues, it's clear the brain is no different than any other organ.

It is our brain's interaction with the rest of the body that sets us somewhat apart from the other animals. Language, the element we hold so dear in protecting our unique status, is given a thorough examination in this book. There are no "language genes", Marcus stresses, but there are identified genes, notably FOXP2, known to impact speech ability. He explains that looking for "genes for" something is futile. Genes interact in too convoluted a manner to expect simple associations between a few nucleotides and something as complicated as speech.

Marcus offers a novel term to counter those railing against the strawman "genetic determinism". Having explained how evolution has led to building brains, he declares them "prewired" but not "hardwired". "Prewired" means that basic functions are spelled out biologically, but don't limit our interaction with our environments. All brains permit flexibility by neurons interacting with each other as conditions vary. We can learn because we are prewired to learn. However, we've only begun the research where our brains are concerned.

Marcus presents this trove of information with amazing clarity. His topics aren't simple mechanisms or ideas, yet he conveys it all with graceful logic. He avoids "dumbing down" the science, yet nothing is lost in his presentation. His theme and supporting examples, buttressed by a glossary and extensive bibliography, are expressed in delightfully accessible prose. Some explanatory graphics depict various elements and mechanisms in furthering the reader's understanding. The underlying concept is "universality" and it's easy to see how his ideas apply to all animal life.

This is a valuable book, easily absorbed by students, professionals in many fields, including, in the final chapter, lawyers. The general public should be the primary market for this book since Marcus makes clear what has been learned may be applied in various ways, from "gene therapy" to "designer children". He doesn't avoid the hard issues in showing how recent science has closed off many myths while opening as many new options. Further research is needed, he argues, to avoid foolish mistakes. Those failing to read this book may make or allow those errors. [stephen a. haines - Ottawa, Canada]"
~ Written on 2004-07-04