Comment by js2
7 hours ago
The original paper is titled "Bipedalism and brain expansion explain human handedness". It doesn't seek to explain why we have a right-handed preference specifically (vs left-handed), but rather why humans have such a strong handedness preference compared to ancestors who had only a mild right-handed preference.
IOW, why handed vs ambidextrous, not so much why left-handed vs right-handed.
> why handed vs ambidextrous
Did it even explain that? I'm ambidextrous, I have no handedness bias, so whichever I pick up to first learn something is the hand I use. So I'm a mix of left-handed and right-handed depending on the task. And yet I didn't really understand why that's odd because of my bipedalism?
There is also a category of people who are “mixed-handed”, who have a strong handedness preference for a given task, but which hand one prefers varies based on the task. I didn’t know about this category until recently, but it describes my personal experience.
Mildly informative Wikipedia article: https://en.wikipedia.org/wiki/Cross-dominance
>why handed vs ambidextrous
may be high dexterity is expensive, brain-wise, i.e. may be the choice given average brain is either 2 hands with mild dexterity or a one of high dexterity at the expense of the other. With tools, etc. the latter choice seem to be preferable and was selected for (and the lucky ones get to have 2 of high dexterity) Bipedalism and brain expansion in this situation are indirectly connected to the handedness as they are enablers and drivers of tools use.