Based on the discussion in the comments here:
Some of us are interested in knowing when hand dominance becomes firmly established.
I'm looking for a general timeline of the related developmental milestones. I know that there's ambiguity and fluidity regarding handedness in young children, but I'm not positive on when the switching becomes less common, and when it zeroes in on one or the other.
Some reports are that it happens quite early, but when 90% of the population ends up being right-handed, I think it's a bit of a self-fulfilling prophecy. Some research suggests it actually happens quite late. I'm not sure if there's more to back up/refute the information found here.
Both of these:
are related questions, but discuss the how/why, not the when.