<p>First of all, asymmetries in apparently symmetric creatures (of which most are) are actually quite typical.  However, in most cases of hand dominance, there is no population-wide hand dominance.  In other words, the population is split 50/50 between left and right handers.  In humans, however, a lack of hand dominance is often associated with cognitive deficits.</p>

<p>In humans, population-wise, we are right-hand dominant (9:1).  There are exceptions to a genetic influence, such as strict schools disciplining children into using their right hand, or an indirect consequence of developmental brain trauma or genetic diseases, but for the most part the right-hand dominance is thought to be a genetic outcome based on the emergent effects of several interacting genes.  That is, there's no particular reason why nature "chose" right over left, just that having a dominant hand allows for more specialization with respect to tool-using which <em>could</em> possibly have given humans with this mutation a competitive edge over their ambidextrous competitors.</p>

<p>A single-gene theory (Corballis, 2009) proposes that there is a dextral and a chance allele of a particular gene and that people born with the dextral allele are likely to be right-handed while people born with the chance allele have equal chance of being left or right-handed.</p>

<p><sub>
Francks, C; DeLisi, LE; Fisher, SE; Laval, SH; Rue, JE; Stein, JF; Monaco, AP (2003). <a href="http://dx.doi.org/10.1086/367548">"Confirmatory evidence for linkage of relative hand skill to 2p12-q11"</a>. American journal of human genetics 72 (2): 499–502. (<a href="http://pubman.mpdl.mpg.de/pubman/item/escidoc:529252:1/component/escidoc:529251/Francks_Confirmatory_Evidence_Am_J.Hum_Gen_2003.pdf">PDF</a>)<br>
Van Agtmael, T; Forrest, SM; Williamson, R (2002). <a href="http://dx.doi.org/doi:10.1038/sj.ejhg.5200851">"Parametric and non-parametric linkage analysis of several candidate regions for genes for human handedness"</a>. European journal of human genetics : EJHG 10 (10): 623–30.<br>
Warren, Diane M.; Stern, Michael; Duggirala, Ravindranath; Dyer, Thomas D.; Almasy, Laura (2006). <a href="http://dx.doi.org/10.1080/13576500600761056">"Heritability and linkage analysis of hand, foot, and eye preference in Mexican Americans"</a>. Laterality: Asymmetries of Body, Brain and Cognition 11 (6): 508–524.<br>
Scerri, T. S.; Brandler, W. M.; Paracchini, S.; Morris, A. P.; Ring, S. M.; Richardson, A. J.; Talcott, J. B.; Stein, J.; Monaco, A. P. (2010). <a href="http://dx.doi.org/10.1093/hmg/ddq475">"PCSK6 is associated with handedness in individuals with dyslexia"</a>. Human Molecular Genetics 20 (3): 608–614.<br>
Michael C Corballis. (2009) <a href="http://dx.doi.org/10.1098/rstb.2008.0232">The evolution and genetics of cerebral asymmetry</a>.  Phil. Trans. R. Soc. B 12, 364 (1519): 867-879
</sub></p>

CC BY-SA 3.0
2013-02-25T16:13:55.277Z
2013-02-25T21:53:51.053Z
2013-02-25T21:53:51.053Z
Keegan Keplinger
<p>How did right handedness win over left handedness in numbers?</p>

<p>Is it only a coincidence that there are more right handed people than left handed ones? Or, has some effect in nature explicitly made right handedness dominant?</p>

CC BY-SA 4.0
2024-08-06T22:49:57.540Z
A clue would be to explore handedness in animals, e.g. https://www.apa.org/monitor/2009/01/chimps
drabsv
CC BY-SA 3.0
2013-02-15T10:48:45.610Z
an interesting discussion of this topic: http://io9.com/5840005/why-are-most-people-right+handed
Jeromy Anglim
CC BY-SA 3.0
2013-02-16T13:48:18.107Z
An interesting read http://www.apa.org/monitor/2009/01/brain.aspx
Caesar
<evolution><behaviorism><genetics>
Why are most people right handed?
hkBattousai
# Why are most people right handed?

(Asked by: username_0 on 2013-02-15)

How did right handedness win over left handedness in numbers?

Is it only a coincidence that there are more right handed people than left handed ones? Or, has some effect in nature explicitly made right handedness dominant?

**Tags:** evolution, behaviorism, genetics

> **Comments:**
> **username_2**: an interesting discussion of this topic: http://io9.com/5840005/why-are-most-people-right+handed  
> **username_3**: An interesting read http://www.apa.org/monitor/2009/01/brain.aspx  
> **username_1**: A clue would be to explore handedness in animals, e.g. https://www.apa.org/monitor/2009/01/chimps  

---

## 1 answers

### Answer by username_4 on 2013-02-25. Score: 7

First of all, asymmetries in apparently symmetric creatures (of which most are) are actually quite typical. However, in most cases of hand dominance, there is no population-wide hand dominance. In other words, the population is split 50/50 between left and right handers. In humans, however, a lack of hand dominance is often associated with cognitive deficits.

In humans, population-wise, we are right-hand dominant (9:1). There are exceptions to a genetic influence, such as strict schools disciplining children into using their right hand, or an indirect consequence of developmental brain trauma or genetic diseases, but for the most part the right-hand dominance is thought to be a genetic outcome based on the emergent effects of several interacting genes. That is, there's no particular reason why nature "chose" right over left, just that having a dominant hand allows for more specialization with respect to tool-using which *could* possibly have given humans with this mutation a competitive edge over their ambidextrous competitors.

A single-gene theory (Corballis, 2009) proposes that there is a dextral and a chance allele of a particular gene and that people born with the dextral allele are likely to be right-handed while people born with the chance allele have equal chance of being left or right-handed.

Francks, C; DeLisi, LE; Fisher, SE; Laval, SH; Rue, JE; Stein, JF; Monaco, AP (2003). ["Confirmatory evidence for linkage of relative hand skill to 2p12-q11"](http://dx.doi.org/10.1086/367548). American journal of human genetics 72 (2): 499–502. ([PDF](http://pubman.mpdl.mpg.de/pubman/item/escidoc:529252:1/component/escidoc:529251/Francks_Confirmatory_Evidence_Am_J.Hum_Gen_2003.pdf))  
Van Agtmael, T; Forrest, SM; Williamson, R (2002). ["Parametric and non-parametric linkage analysis of several candidate regions for genes for human handedness"](http://dx.doi.org/doi:10.1038/sj.ejhg.5200851). European journal of human genetics : EJHG 10 (10): 623–30.  
Warren, Diane M.; Stern, Michael; Duggirala, Ravindranath; Dyer, Thomas D.; Almasy, Laura (2006). ["Heritability and linkage analysis of hand, foot, and eye preference in Mexican Americans"](http://dx.doi.org/10.1080/13576500600761056). Laterality: Asymmetries of Body, Brain and Cognition 11 (6): 508–524.  
Scerri, T. S.; Brandler, W. M.; Paracchini, S.; Morris, A. P.; Ring, S. M.; Richardson, A. J.; Talcott, J. B.; Stein, J.; Monaco, A. P. (2010). ["PCSK6 is associated with handedness in individuals with dyslexia"](http://dx.doi.org/10.1093/hmg/ddq475). Human Molecular Genetics 20 (3): 608–614.  
Michael C Corballis. (2009) [The evolution and genetics of cerebral asymmetry](http://dx.doi.org/10.1098/rstb.2008.0232). Phil. Trans. R. Soc. B 12, 364 (1519): 867-879


---

