Table of Contents

Introduction. The Puzzle of Handedness and Cerebral Speech. The Right Shift Theory. Human Handedness: Discrete Types or Continuous Varieties? The Right Shift Theory of Handedness: Chance Plus or Minus Right Loading. A Right Shift Factor for Left Cerebral Dominance. The Single Gene Theory of Right Shift. Explorations in the Light of the Theory. Stability and Change: Handedness with Age, Sex and Time. A Single Gene with Variable Expression for Genotype, Sex and Twinning. Other Asymmetries of Brain and Behaviour. Predicting Associations Between Asymmetries. A Genetic Balanced Polymorphism with Heterozygote Advantage. Why Right Shift and Why Genetic Variability? The Advantages and Disadvantages of the RS+ Gene. Heterozygote Advantage. What are the Disadvantages of Right Shift? Spatial and Mathematical Reasoning, Art, Music, Surgery and Sport. Speech, Phonology and Varieties of Dyslexia: The Costs and Benefits of the RS+ Gene. Schizophrenia and Autism: The Theory of an Agnosic RS+ Gene. Independent Replications, Challenges and Theories. Independent Tests and Challenges. Alternative Theories or Variations on a Theme? Conclusions. Summary: What, How, and Why? Appendices.

Reviews

'This is a milestone contribution. It pulls the field together around the right shift theory and sets the course for future investigation.' - Tim Crow, University of Oxford 'Few can afford to ignore Annett's theory... she has cast her stamp upon the field of handedness as no other investigator has done.' - Alan Beaton, University of Swansea