Why are there so many more people who handle their right hand better than their left?
In this article we will analyze the hypothesis of the fight that talks about left-handedness, fighting and survival, and we will turn to the most recent empirical evidence that explains why there are more right-handed than left-handed according to an interesting line of research.
Left-handed, right-handed and ambidextrous
People with left-handedness are those who tend to use, preferentially, the left side of their body (that is, their hands and feet).
The left-hander is a minority phenotype in the human species ; that is, there are more right-handed people (who preferably use the right limbs) than left-handed people.
In fact, between 8 and 13% of the world population has left-handedness; on the other hand, there are more left-handed men than left-handed women (13% vs. 9%), although why is not known. Finally, it is worth mentioning that those people who use the right and left limbs interchangeably are called ambidextrous.
Why there are more right-handed than left-handed, according to research
As we anticipated in the introduction, this article focuses on the fact that there are many more people who have the right hand as their dominant hand. Why are there more right-handed than left-handed? But before getting into this question, let’s clarify why there are left-handers in the population, according to the hypothesis of the struggle.
According to this hypothesis, there are left-handers in the population because in the past, left-handed people had an advantage in violent intrasexual competitions. This, according to this hypothesis, would explain why the left-hander persisted over time.
But what does the fight hypothesis say specifically about the left-hander?
According to this hypothesis, there is a polymorphism (polymorphism implies the existence, in a population, of multiple alleles of a gene) in human hands, which is maintained over time through a process of natural selection ; in the case of left-handed people, this process is a frequency-dependent selection.
What does this mean? That when a trait offers a certain biological efficacy to a certain species (increasing its probability of survival), said trait remains, even if it is a minority (such as left-handedness).
How is this extrapolated to the field of fighting and left-handedness? Right-handed fighters are used to fighting other skilled fighters ; Therefore, when competing against a left-handed wrestler, the latter will have a certain advantage in the fight (and therefore will surely have a greater chance of winning), since the left-handed wrestler is more used to fighting a right-hander than the right-hander against a left handed.
Empirical evidence: study
We found different studies showing how left-handed men are overrepresented among modern professional wrestlers. A recent study (2019) by Richardson and Gilman also set out to analyze the question of why there are more right-handers than left-handers and focused on the world of boxing and fighting.
This study analyzed a total of 13,800 boxers and fighters of different martial arts, of mixed type.
That is, the sample included both men and women. However, it should be mentioned that of the total number of boxers, 10,445 were men (8,666 right-handed and 1,779 left-handed), 1,314 were women (1,150 right-handed and 164 left-handed) and 2,100 were MMA (mixed martial arts) fighters (1,770 right-handed and 393 left-handed) .
Through these data we see how left-handed men represent 12.6% of the general population, 17% of men within the world of boxing, and 18.7% in the MMA sector; In the case of women, they represent 9.9% of the general population, and 12.5% of female boxers. We see how, in both cases, the left-hander is overrepresented in the world of wrestling.
Objectives of the study
The study tried to verify two aspects; on the one hand, whether or not there is an over-representation of left-handed wrestlers compared to right-handers, and on the other, whether they accumulate more victories than right-handers.
The results of the Richardson and Gilman study revealed that left-handed boxers and fighters did indeed have more wins (number of fights won) than right-handers. This was reflected in both male and female wrestlers.
In addition, the fighting capacity of the male and female wrestlers was also evaluated, through an objective measure, and the results were in the same line; the left-handed people had a better fighting capacity compared to the right-handed ones.
Another hypothesis that was raised and analyzed in the aforementioned study is another one already suggested by previous studies, and it was the following: the fact that left-handed fighters show greater variation in combat capacity. This hypothesis could not be confirmed, since this variation was not observed in left-handed wrestlers.
As we have seen, analyzing the question of why there are more right-handers than left-handers, we reach the following conclusion: the fact that left-handers are in the minority (for this reason they are overrepresented), makes their actions and techniques more difficult to predict from their rivals.
This can be explained by the tendency of right-handed rivals to attend mainly to the right hand of their opponent (it is an attentional bias), and this tendency would appear because right-handers would be used (when competing generally with right-handed rivals) to attend to this hand.
Verification of the hypothesis
Thus, what is currently happening in the field of wrestling and boxing, we can extrapolate to our ancestors; In this way, it is probable that our left-handed ancestors, as the fighting hypothesis suggests, had a certain advantage in violent combats (these being more frequent in the past than today), which gave them a certain evolutionary advantage .
In this way, we see how the hypothesis of the fight would be fulfilled, since the fact of being left-handed or left-handed implies an advantage in this type of sports.
- Bejarano, MA & Naranjo, J. (2014) Laterality and sports performance. Arch Med Sport, 31 (3), 200-204.
- Hardyck, C., & Petrinovich, LF (1977). Left-handedness, Psychological Bulletin, 84, 385–404.
- Richardson, T. & Gilman, RT (2019). Left-handedness is associated with greater fighting success in humans. Sci Rep 9, 15402.