Sentence:  Recent experiments and observations, however, prove that <WSD>single-handedness</WSD> is merely the result of faulty or restricted education. Careful observations have shown that out of every hundred persons born into this world eighty are congenitally ambidextrous — that is to say, they will instinctively reach for an object with either hand 
Meaning of the word marked with <WSD> tags:  The quality of having a dominant hand; left-handedness or right-handedness.