If the correlation is 0.2 then it explains 4% of the variance. If it's 0.5, then 25%. I'm not sure how you got your numbers, can you clarify? Also 10% variance

If the correlation is 0.2 then it explains 4% of the variance. If it's 0.5, then 25%. I'm not sure how you got your numbers, can you clarify? Also 10% variance explained in social science is considered pretty good (which is depressing, but such is life).