A Look at the Effect of Hand Dominance on Learning

INTRODUCTION

Interest in the dominant hands of individuals is not a modern phenomenon. It arose during the nineteenth century when the views on the functional localization in the cerebral cortex were developing (Dax, 1865). Determining the hand preferences of an individual is important to psychologists, clinical neurologists and research scientists because hand preference is considered a marker for cerebral hemispheric dominance for speech and language. It is also an inexpensive, non-invasive way for physicians and scientists to reliably identify the hemisphere controlling a person's speech ability; this information is useful both for treatment and basic research into the brain (Springer and Deutsch, 1997).

Hand dominance has been associated with many conditions; in the case of left handedness, most of them deleterious. And in Nigeria, most cultures associate left handedness with numerous myths and consider it disrespectful, or even a taboo to carry out certain tasks with the left hand-such as giving or collecting things from elders, pointing, eating, etc. It is thus common practice for parents or relatives of left handed children to teach them to stop this apparently abnormal behaviour (Adeyemi-Doro, 1993).

This attitude is not surprising, for even scientific studies still attempt to link left-handers with socially undesirable behaviours, such as psychosis or criminal activity. Left-handedness has been associated with developmental disorders including dyslexia, stuttering, mental retardation and autism (Geschwind and Behan, 1982; Batheja and McManus, 1985; Porac et al., 1980). It also has a high association with disease and disease risk factors (Stellman et al., 1997); shortened life span (Ashton, 1981; Coren and Halpern, 1991; Fleminger et al., 1977; Kuhlemeier, 1991; Lalumière et al., 2000; Lansky, 1988; Porac et al., 1980; Tan, 1983) and even increased risk of breast cancer (Anonymous, 2005).

Throughout the ages, left-handers have been regarded with a certain amount of suspicion by society as a whole and are viewed as rather unsavoury, educationally backward and anti-social characters by psychologists (Dacey, 1989). They have also been considered as obstinate introverts, who declined to use their right hand to write with, not because they could not, but because they would not! (Burt, 1937) who provided the greatest insight into the position of left-handers during the first part of the twentieth century. This link with educational backwardness and nonconformity possibly contributed to the inflexible attitude adopted by both parents and teachers at that time, towards forcing their children to use their right hand for writing and other manual tasks.

While some studies have suggested an unusually high proportion of developmental problems and mental retardation, left-handedness is also notorious among the most gifted of humans. Although left-handedness is associated with many unpleasant things, it has its advantages. That is, left-handedness may not be good or bad in the final analysis, rather simply different (Geschwind and Galaburda, 1985).

The Incas thought that to be left-handed was lucky and one of their great chiefs was Lloque Yupan Qui, which translates as left-handed (DeKay, 1979). Certainly the modern human is predominantly right-handed. Also, no significant difference between gifted and non-gifted children in distribution of left and right handed writing has been determined (Szeszko et al., 1997).

Most people working with children are interested in the development of the hand preferences because of both its impact on hand skill and its possible relationship to brain function. Better understanding how handedness relates to brain function is relevant to many people, such as academic researchers, medical clinicians, neurological patients, educators and left-handers themselves.

This study thus tries to find out the effect of handedness on learning using children from Delta State, Nigeria, in an attempt to clarify the relationship between handedness and functional brain specializations such as learning. Learning more about the mechanisms that underlie these relationships, may help lead to better understanding of a wide range of seemingly unrelated issues such as dyslexia, stuttering, human variation, comparative brain research, developmental neurobiology of the brain and the origins of human language.