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Published on: March 21, 2025
Why are some people left-handed? An evolutionary perspective
V Llaurens1, M Raymond, C Faurie
1Institut des Sciences de l'Evolution de Montpellier (UMR CNRS 5554), Université de Montpellier, Montpellier Cedex 5, France. violaine.llaurens@univ-montp2.fr
Summary
Left-handedness, though rare, may offer fighting advantages but incurs evolutionary costs. Understanding the persistence of this human trait requires further study into fitness differences between left- and right-handers.
Area of Science:
- Human evolution
- Behavioral genetics
Background:
- Left-handedness (LH) is a ubiquitous human trait with geographical variations.
- Its persistence suggests evolutionary pressures, possibly negative frequency-dependent selection.
- LH may confer advantages in conflict but has associated costs, leading to its low frequency.
Purpose of the Study:
- To review literature on the evolutionary dynamics of handedness polymorphism.
- To explore factors influencing hand preference and its fitness consequences.
- To synthesize evolutionary perspectives on the persistence of left-handedness.
Main Methods:
- Literature review of existing studies on handedness.
- Analysis of genetic, hormonal, developmental, and cultural influences.
- Examination of potential fitness costs and benefits associated with left-handedness.
Main Results:
- Hand preference is a heritable trait.
- Multiple factors influence handedness, including genetics and environment.
- Evidence suggests potential fitness trade-offs for left-handers.
Conclusions:
- The evolutionary dynamics of handedness polymorphism are complex and not fully understood.
- Further research is needed to assess fitness differences between right- and left-handers.
- Evolutionary perspectives on handedness provide insights into human trait persistence.
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