left and right handers

[janelle_ire]

hey my sis asked me jus nw why people are left handed nd why people are right handed..i no its decided at some point in the womb but if anyone has any info on this id appreciate it if you could help me out...ty

[smudge]

I am left handed & left footed, but have no idea why.

[janelle_ire]

no what i mean is why people rnt all right handed r why dey rnt all left handed...

[kamijamey]

Actually left or right handedness isnt really determined until about four years of age.  The child may start to prefer a certain hand earlier, but when they begin to write and color proficiently is when they actually "pick" a hand.  I think it has to do with genetics as well, but the hand that we consider ourselves as- is usually stronger and able to do more complicated tasks. So what happens is that one just "takes over" as the dominant hand.  We also have a dominant eye as well, and its not always the same as which hand we use.  I guess we have a dominant hand because otherwise they both would reach out to do something, this way the skills are more refined in usually one hand- for things like writing. 

Sorry I dont have a biological answer, but this is stuff I have heard the past few years while I was in college.