The belief of left-handers are smarter than right-handers has been around for quite some time.
Therefore, it is worth knowing the truth behind this belief with scientific evidence.
How Handedness Been Controlled By Brain
The cerebral cortex of the forebrain, when viewed from the top is divided into two mirror–images which are known as the left and right hemispheres. With the exception of the internal organ such as the heart, the body is basically bilaterally symmetrical, that is the receptive and control centres for one side of the body are in the opposite hemisphere brain. Most times it is said that there’s often a tendency, sometimes strong, for one or the other hemisphere to be especially dominant in the different processes or functions known as lateralization
Lateralisation is also the preference for using one side of the body more than the other in performing special tasks depending upon which hemisphere is dominant that is, if the left hemisphere of a person is more dominant than the other, the person tends to be right-handed. On the other hand, if a person’s right hemisphere is more dominant, the person tends to use the left hand more than the other (usually known as the “left-handers”)
Left-handedness And Intelligence
Department of Sociology/Psychology, Olabisi Onabanjo University, Ago-Iwoye, Nigeria has been conducted a study to examine the relationship between left-handedness and increased intelligence among 200 university undergraduates of their university.
They equally divided the participants into two groups which are 100 lefthanders and 100 right-handers. The questionnaire was distributed to all participants along with the reassurance of confidentiality of their responses. The whole duration of the fieldwork was a total of five days after which the questionnaires were retrieved. The researcher could only retrieve (170) out of the (200) questionnaire distributed, after which these questionnaires were scored and properly analysed using the statistical software called (SPSS).
From the results gathered, it was obvious that while some other factors might contribute to the intelligence level of an individual, left-handedness offers an additional advantage over right-handedness. This can be said to be that left-handed individuals will be more intelligent in the areas of spatial and musical intelligence because they would have a large repository of control because this area is controlled by the hemisphere responsible for their left-handedness.
Also, educational level and environment have a link with the intelligence of the individual. In fact, the IQ of an individual can be improved by training. That is, a left-handed individual can achieve giant strides academically because the asymmetry of the brain hemispheres gives him/her good coordination, retention, and memory.
In 2007, the University of Sargodha, Pakistan has conducted a study to find out the effect of handedness on the intelligence level of students. There were 150 participants of intermediate, graduate, and postgraduate students of Sargodha district including an equal number of left and right-handers. They were divided into three groups of equal size with respect to the educational level which ranged from intermediate to post-graduate. The participants were asked to take a test that contained sixty problems. Results indicated that left-handed participants were significantly more intelligent than right-handed participants.
According to the study conducted by The University of Oxford with about 400,000 participants, they have discovered that left-handed people have better coordination with the language areas of the left and right sides of the brain which suggests that the left-handers may have better verbal skills.
According to the study published by Cambridge University in 2010, left-handers have lower levels of general cognitive ability – GCA compared to right-handers.
There was another study about the relationship between intelligence and they have been discovered the Right-handers have negligibly higher IQ scores than left-handers.
Based on the many types of research of handedness and intelligence, we can’t exactly say that the left or right-handers are intelligent than one another.