The study found that those of us who play WoW for socialization are higher on the scales of agreeableness, neuroticism, and openness. Neurotic in this sense might not mean what you think it means; it's part of the Big Five personality dimensions that are commonly used in psychology. People that are high on the scale of neuroticism are, in general, less emotionally stable, have higher anxiety, and can get angry quicker (this shouldn't surprise anyone that reads the forums and the tweets Blizzard staff get). Neuroticism doesn't mean that you're insane, just that you have some of the personality traits described above. Quite literally we are all somewhat neurotic in this sense, it just matters how far along the scale you are (those on the extreme high-end of the scale are where the traditional/societal definition comes from).
Those that seek leadership in WoW tend to be high on the extraverted (meaning they prefer groups and interactions with others), openness, and conscientious scales. Those in leadership (as one could reasonably expect) tend to be highly organized, like to plan things out, and are lower on the neuroticism scale.