Skipping the editorializing and going right to the paper, and I'm quite interested the paper quite notably appears to skip over surveying the tendency for this

Skipping the editorializing and going right to the paper, and I'm quite interested the paper quite notably appears to skip over surveying the tendency for this personality trait to appear- ie. we don't yet have statistics of what demographics have higher likelihood of elevated scoring for this trait. It seems intuitive to me that this would be one of the primary ways to evaluate that this trait is legitimate; why was it so left out?