My theory? Lefty synapses seem to fire more rapidly to begin with than do righty synapses.
Combine that with the effect of education on the brain and it's reasonable to infer faster, numerically greater and more content rich posting from lefties, as compared with righties, over comparable time frames.
Sounds kind of scientific, doesn't it? Smart-ass quotient is also off the charts for lefties. Playful nature, I think.
Education boosts brain function long after school, study shows