Right-handed Speech

Being right-handed is much more common than being left-handed and the way we are wired means that the left hemisphere of the brain is involved with control of the right hand. The left side of the brain is associated with communication such as speech.

We learn to speak when we’re small, but before that we point and grunt. And the way we fond parents respond, mere gestures are a very effective way of communicating. Meunier et al wondered if the use of gestures preceded speech in an evolutionary path and if that was facilitated by the predominance of right-handedness in our species (1).

The result of that thought was a study of other primates to see if they also were right-handed in terms of gestures but not necessarily in terms of getting hold of the object that they were indicating.  They chose a group of 12 baboons to test this with and at the same time tried a similar test with 10 infants at 14, 17, and 20 months old.

The tendency of baboons and babies was to point at what they wanted with the right hand, but when they were able to pick it up, they chose the hand nearest to the prize.

The conclusion was that the split function of the brain – lateralization – with the left hemisphere being our speech section, in combination with the tendency to be right-handed, led in evolutionary terms to us evolving past gestures through to making the interminable stump speeches full of meaningless promises favored by our politicians.

I should also note that our speech centers are also capable of producing glorious musical performances and perhaps that ameliorates the other nonsense.

  1. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0033959

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