Chris McManus

Reading this book took me less time than I expected, as it was surprisingly engaging. I would recommend it to anyone who wants to know (a lot) more about the concepts of symmetry/asymmetry, left/right, and handedness. Some of the disciplines the author brings in are biology, chemistry, physics, linguistics, literature, philosophy, psychology, and history. There are lots of little diagrams to illustrate his points. Some of the details of the chemistry and physics were beyond me, but I was able to get the gist of it. This one had both sides of my brain working.… (more)

In Right Hand, Left Hand, Chris McManus posits that there is no such thing as being ambidextrous. Everyone is either strongly right-handed, strongly left-handed, weakly right-handed, or weakly left-handed. There’s even a questionnaire to determine your handedness. If you answer the questions equally with left and right, it only means that you need a more detailed questionnaire. This, I think, is silly. While having someone answer a million question survey may finally tease out whether someone is slightly biased to one side, I don’t think that this will matter much to the real world outside of academia.

What’s most interesting about Right Hand, Left Hand is the overarching theory that McManus spins by pulling together various research in all sorts of disciplines in order to explain handedness in the universe. The theory is this: because of the deep observed asymmetry in physics, one of the results is culture and civilization today. Whoa, whoa, whoa, you might say–that’s a pretty big theory, one that on the face of it doesn’t wash. Well, here’s his train of thought:

*Experimental particle physics has shown that the universe is asymmetrical. (Example: A Nobel prize winning experiment involving cobalt-60 contradicting the Law of Conservation of Parity)
*Perhaps the asymmetry of subatomic particles have led to the abundance of D-sugars and L-amino acids present in life.
*The L-amino acids determine the structure of proteins in a living body. It’s been known, since about 2000, that there are cilia in the developing embryo that beat a certain way (perhaps due to the protein structure) and create a gradient of signaling molecules which cause our hearts to develop on the left side of our body. This may also be under genetic control. McManus speculates that a similar mechanism causes our brains to also develop asymmetrically.
*Because of asymmetrical brains, we all favor one side or another. Since using the right hand is dominant among humans, this has led to many peculiar cultural developments such as using the right hand for one thing and the left hand for another, to develop peculiarities in language and associations to each side, and to equate right with good and left with bad.

Other than some particular cultural things which appear to have developed by chance (such as on which side of the road you drive on, the direction in which the hands of a clock turns, and from which way you start writing–i.e. left to right in English and right to left in Arabic), McManus’s theory sounds logical and presents a nice and pat explanation for how things came to be. The only problem is, there’s no experimental evidence to prove that the next step is a consequence of the previous step. (more)… (more)

When my daughter was young she attended the Royal Institution's Christmas Lectures for several years, and one of the early lectures she went to was on the subject of 'handedness'. She was very excited by the ideas she had heard and conveyed her fascination to me - ever since then I too have been interested in the subject. I was thrilled to find this book, for which the author won the 2003 Aventis General Prize for Science Books. It is a meaty work, McManus covers the history of the study of asymmetry, biology, language, neuro-physiology, particle physics as they pertain to handedness, and much more besides. I have been reading it little by little, trying to absorb each new idea before I move on. Asymmetry permeates our daily lives and this book goes a long way towards explaining why that is.… (more)