TLDR: Evidence from Neanderthal teeth and cave paintings reveals most humans and ancestors were right-handed, linked to brain lateralization and tool use, with left-handedness offering unique advantages.
This article is a summary of a You Tube video “How Humans Became (Mostly) Right-Handed” by PBS Eons
Key Takeaways:
- Most Neanderthals were right-handed, similar to the majority of Homo sapiens, with evidence from teeth scratches indicating a long-standing preference for the right hand in human lineage.
- Human handedness is more of a spectrum, with some people being strongly right or left-handed and others falling somewhere in between.
- Handedness is linked to brain lateralization, where different cognitive processes take place in different parts of the brain, contributing to the preference for using one hand over another.
- Evidence of right-handedness dates back millions of years, with cave paintings and fossilized teeth scratches indicating that our ancestors preferred using their right hand.
- Hand preference is observable in the human skeleton, where the dominant arm exhibits thicker bone density due to repeated use.
- Right-handedness may have evolutionary advantages, including better coordination, memory, and verbal skills, and might offer a competitive edge in physical combat, especially among left-handed individuals.
- Handedness could be partially heritable, with genetics playing a role, though no single “handedness gene” has been identified. It’s suggested that several genes might have minor effects.
- The development of tool use and bipedalism (walking upright) are significant factors in the evolution of hand preference, with implications for the favoring of the right hand across hominin species.
- Left-handedness, while less common, may have emerged as a beneficial trait in certain contexts, such as physical combat, where lefties can have the element of surprise.
- The phenomenon of handedness illustrates the complexity and variability of human traits, showing that there’s no single “right” way to be human, with each variation offering its own set of advantages.
