Why do humans alone,among all animal species,display a distinct of left or right handedness?

Question

Is that tre about it?

Why do humans alone,among all animal species,display a distinct of left or right handedness?Not even our closest relatives among the apes posses such decided lateral asymmetry as psychologists call it.Yet about 90 percent of every human population that has ever lived appears to have been right-handed.professor Bryan turner at deakin university has studied the research literature on left-handedness and found that handedness goes with sidedness.So nine out of every ten people are right-handed and eight are right-footed.He noted that this distinctive asymmetry in the human population is itself systematic.Humans think in categories:black and white,up and down,left and right.It;s a system of signs that enables us to categorise phenomena that are essentially ambiguous.

Research shows that there is a genetic or inherited element to handedness.But while left handedness tends to run in families,neither left hander nor right

Answer 1

There is a theory that human brains became large when we started using tools and started throwing stones and weapons.  For extremely precise control, the brain needs to assign many more neurons for a particular task.  Humans are extremely good at difficult tasks such as learning to drive, learning to knit, learning to build factory parts, learning to play sports, and all other such things that take practice.  When Homo erectus started throwing hand axes, its brain became much larger.  Probably some of that growth is for language and intelligence but a large portion is also toward being more adept at tools or particular tasks.  By being right or left handed, the brain does not need to grow as large and it can still generally perform a particular task such as tool making or throwing.  The intricate tasks are concentrated on one hand making the brain drain less and also the arm that performs the task becomes larger and stronger.  I wouldn't be surprised that chimps also show some handedness but just becuase a cat is more likely to use one paw or the other does not seem to me to be the same thing especially if there is no tendency to use one or the other.  My wife is a lefty but she was taught to use her right to write and other things.  It is still obvious to me she is naturally left handed.  My twin brother is left handed.  Clearly there is a genetic tendency in humans to greatly favor one side or the other.  A slight tendency in other animals just doesn't seem the same but I could be wrong.  In any case, I wonder if it is most prevalent in animals that learn to use limps such as chimps or apes, monkeys, cats, and to others.

Answer 2

the left side of the brain controls the right side of the body- which is the rational, non-subjective side.  This side gets used more by default because that is the way people have developed over time along with society making all of it's rules, organization and laws.

Answer 3

yes kabir my dear friend it is 100 percent true.

Answer 4

the way of the world

Answer 5

Humans alone DON'T display a distinct handedness.

Chimps do:

http://www.apa.org/releases/chimpbrains....

Great Apes:

http://www.springerlink.com/content/pp6t...

Cats:

http://www.bbc.co.uk/nature/animals/pets...

Dogs:

http://faculty.uml.edu/mark_hines/81.452...

I'm sorry, the premise of your article is wrong.

Answer 6

Funny, I thought that chimps and orangs also showed distinct "handedness." This is physiology, not psychology.