Introduction.- What is Left-Handedness?.- Brain Asymmetries: Left-Right Differences in the Brain.- How Do Left-Handedness and Brain Asymmetries Occur?.- Left-Pawedness: Brain Asymmetries in the Animal Kingdom.- The Evolution of Left-Handedness and Brain Asymmetries.- Left-Handedness and Cognitive Functions.- Do Left-Handers Have an Advantage in Sports?.- Relearning Handedness and Its Consequences.- Left-Handedness and Brain Asymmetries in the Clinical Context.