Why Is Right-Handedness More Common Than Left-Handedness?

[bijanc]

Never heard a compelling theory? Any thoughts?

(once read a book, "The Throwing Madonna", that proposed one)

http://williamcalvin.com/bk2/bk2ch1.htm

[Marlow]

Isn't the real question: why are the right and left brain hemi-spheres so different, cuz they govern that sort of thing (I think). Our art department is full of right-brainers and they drive me CRAZY!

[dukehjsteve]

Why ? Because only the best and the brightest ( about 12 % ) of the human population is left handed. Simple, isn't it ?!

[Pego]

Re: Why Is Right-Handedness More Common Than Left-Handedness

Never heard a compelling theory? Any thoughts?

(once read a book, "The Throwing Madonna", that proposed one)

http://williamcalvin.com/bk2/bk2ch1.htm

I can explain how it is, not quite why.
Left temporal lobe in humans is considerably larger than right. There is a so called planum temporale that houses the primary speech center. The handedness is, however, phylogenetically considerably older than origination of language. You may have observed that all flamingos always stand on their right leg.
Interestingly, up to 50% of the left-handers still have the left hemisphere as dominant.

[Track Family]

I'm ambidextrous, one of my children is ambidextrous and one is exclusively left handed :shock: 8-)

[Pego]

I'm ambidextrous, one of my children is ambidextrous and one is exclusively left handed :shock: 8-)

The hand you right with is what your handedness is, regardless how handy (klutzy) you are with either.

[Marlow]

The hand you right with

So are you left or write-handed? :twisted:

[lonewolf]

Sly, Marlow

[Track Family]

I'm ambidextrous, one of my children is ambidextrous and one is exclusively left handed :shock: 8-)

The hand you right with is what your handedness is, regardless how handy (klutzy) you are with either.

I'm quite aware, but I am equal in left and right with great penmanship in both :wink: :lol: 8-) When at work in business meetings, it is often brought up that "she's alternating again"......lol For instance, in a meeting when I have to sit next to a department chairperson, if they sit to my right, I use my left hand or vice versa :lol:

[TrackDaddy]

I'm ambidextrous, one of my children is ambidextrous and one is exclusively left handed :shock: 8-)

The hand you right with is what your handedness is, regardless how handy (klutzy) you are with either.

Who wrote that rule?

[Daisy]

Who wrote that rule?

My guess is that is how neurologists define it.

As to why, I'm not aware of a simple genetic component, so it might well be due to a stochastic event during early development. X-inactivation works this way too which is why each calico cat has a different pattern.

Why ? Because only the best and the brightest ( about 12 % ) of the human population is left handed. Simple, isn't it ?!

So bright they burn out too soon? :?

Look at the following reference i found.

• Left-handedness: A marker for decreased survival fitness.
  Coren, Stanley; Halpern, Diane F.
  Psychological Bulletin. Vol 109(1), Jan 1991, 90-106.

From the Abstract

Life span studies have shown that the population percentage of left-handers diminishes steadily, so that they are drastically underrepresented in the oldest age groups. Data are reviewed that indicate that this population trend is due to the reduced longevity of left-handers.

[TrackDaddy]

Life span studies have shown that the population percentage of left-handers diminishes steadily, so that they are drastically underrepresented in the oldest age groups. Data are reviewed that indicate that this population trend is due to the reduced longevity of left-handers.

Can it be due to the perils of managing life in a right-handed world?

[Daisy]

Good point, and it is one of the things they discuss.

Here is more from the abstract. I don't have access to the actual paper.

Some of the elevated risk for sinistrals is apparently due to environmental factors that elevate their accident susceptibility. Further evidence suggests that left-handedness may be a marker for birth stress related neuropathy, developmental delays and irregularities, and deficiencies in the immune system due to the intrauterine hormonal environment.

[Marlow]

Can it be due to the perils of managing life in a right-handed world?

Lefties trying to cut with right-handed scissors often end up stabbing themselves in the eye. That severely curtails their survival chances.

[Jack Slocombe]

The answer is simple. There are more righties because the golf club mfrs make more right handed clubs. No money in making lefties. Scheesch!