Why are there more right-handed than left-handed?

In this article we will analyze the hypothesis of the fight that talks about left-handedness, fight and survival, and we will resort 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

Left-handed people are those who tend to use, preferably, the left side of their body (that is, their hands and feet).

Left-handedness is a minority phenotype in the human species; that is, there are more right-handed people (who preferably use the right extremities) 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 should be mentioned that those people who use the right and left extremities 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 the dominant hand. Why are there more right-handed than left-handed? But before going into this question, let's clarify why there are left-handed people in the population, according to the hypothesis of the fight.

According to this hypothesis, there are left-handed people in the population because in the past, left-handed people had an advantage in violent intrasexual type competitions. This, according to this hypothesis, would explain why the left foot persisted in time.

Fight hypothesis

But what does the hypothesis of the fight on the left-hander concretely say?

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 selection dependent on frequency.

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 in the case that it is a minority (such as left-handedness).

How is this extrapolated to the field of struggle and left-handedness? Right-handed fighters are used to fighting other also right-handed fighters; therefore, when they compete against a left-handed fighter, the latter will have a certain advantage in the fight (and therefore, will probably have a greater probability of winning), since the left-handed fighter is more used to fighting against a right-handed man than the right-handed man against a left handed.

Empirical evidence: study

We found different studies showing how left-handed men are over-represented among modern professional wrestlers. A recent (2019) study by Richardson and Gilman also raised the issue of why there are more right-handers than left-handers and focused on the world of boxing and fighting.

Shows

This study analyzed a total of 13,800 boxers and fighters of different martial arts, of mixed type.


In other words, the sample included men and women. However, it is worth mentioning that of the total 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 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 in 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 over-represented in the world of fighting.

Study objectives

The study tried to verify two aspects; On the one hand, whether or not there is an overrepresentation of left-handed fighters compared to right-handers, and on the other, whether they accumulate more victories than right-handers.

Results

Results from the Richardson and Gilman study revealed that left-handed boxers and fighters did indeed have more wins (number of fights won) than right-handed fighters. This was reflected in both male and female wrestlers.

In addition, the fighting capacity of the fighters was also evaluated, through an objective measure, and the results were in the same line; the left-handed had a better fighting capacity compared to the right-handed.

Another hypothesis that was raised and analyzed in the aforementioned study is another already suggested by previous studies, and was the following: the fact that left-handed fighters show a greater variation in combat ability. This hypothesis could not be confirmed, since such variation was not observed in left-handed fighters.

Conclusions

As we have seen, analyzing the question of why there are more right-handed than left-handed, we come to the following conclusion: the fact that left-handed people are a minority (therefore they are over-represented), makes their actions and techniques more difficult to predict due to their rivals.

This can be explained by the tendency of right-handed rivals to mainly serve the right hand of their opponent (it is an attention bias), and this tendency would appear because right-handed people would be used (when competing generally with right-handed rivals) to attend to said right hand. hand.

Hypothesis verification

Thus, what is currently happening in the field of fighting and boxing, we can extrapolate to our ancestors; In this way, it is probable that our left-handed ancestors, as the fight hypothesis suggests, had a certain advantage in violent combats (these being, moreover, more frequent in the past than today), which gave them a certain evolutionary advantage. .

In this way, we see how the fight hypothesis would be fulfilled, since being left-handed or left-handed implies an advantage in this type of sports.