Right Hand, Left Hand: The Origins of Asymmetry in Brains, Bodies, Atoms and Cultures
Is failure of parity conservation in physics the reason conservatives are called right-wingers and liberals are called left-wingers? If the very concept eludes you, you need to read Chris McManus's grand unified theory of asymmetry. Professor of psychology and medical education at University College London and editor of the journal Laterality, McManus brings a lively erudition to "the world (cosmos), the small (micros) and the great (megas) -- each with its own handedness." Under his tutelage, you will learn that one and a half million years ago, Homo habilis invented the toothpick and held it with the right hand, that the name of the Aztec war god, Huitzilopochtli, means "left-handed hummingbird," and that left-handedness was at one time illegal in Albania. You will encounter Immanuel Kant ruminating over absolute versus relational space, Dr. Thomas Watson describing situs inversus, Louis Pasteur discovering dextro- and levo-enantiomers, Paul Broca examining an aphasic patient who could say only the word "tan," Ernst Mach declaring that a symmetric brain cannot distinguish asymmetric stimuli or make asymmetric responses, and Wolfgang Pauli pondering whether "the Lord is a weak-left-hander." You will gaze on Paolo Uccello's 15th-century fresco of a clock that goes counterclockwise, Johann Tischbein's portrait of Goethe showing the Great Man with two left feet, and Federico Fellini's witty doodles after a stroke that resulted in hemispatial neglect. Gustave Coriolis will explain to you why tornadoes in the northern hemisphere spin counterclockwise whereas tornadoes in the southern hemisphere spin clockwise, and Richard Feynman will explain to you why mirrors do not reverse right and left but rather front and back. You will also be introduced to Professor McManus's own genetic model of right- and left-handedness and to his belief that the persistence of a gene allowing a small minority of the population to be left-handed might be adaptive for the population as a whole. After this intellectual smorgasbord, will you be persuaded that perturbations of the weak force are the reason that Edward Kennedy sits on one side of the aisle and Trent Lott on the other? I was not; rather, I was reminded of Murray Gell-Mann's remark (referring to Roger Penrose's attempt to explain consciousness in terms of quantum gravity) that we do not deal with earthquakes in terms of quarks. Persuaded or not, however, you will greatly enjoy the time you spend in Professor McManus's company.John C.M. Brust, M.D.Copyright © 2003 Massachusetts Medical Society. All rights reserved. The New England Journal of Medicine is a registered trademark of the MMS.--This text refers to an out of print or unavailable edition of this title.