Proves nothing. Is probably pretty normal for everyone.
You don't need to prove it. That's your first giveaway, then you can correlate their behavior to be more sure. Knowing someone has bad intentions nullifies them, in person anyway... The sad part is having to be psuedo-psychopathic yourself to eliminate them.
The why could be more interesting.
My theory is more pressure on the left eye from the front-left hemisphere of the brain being larger than the front-right hemisphere.
What were you expecting?
Changed my name angee as you asked so nicely!
Very interesting. A year or two ago, I did a lot of reading up on 2D:4D ratio correlations as part of my interest in the autism-psychosis diametric theory. While there may not be a "musical face," numerous studies have found that a low 2D:4D ratio (high prenatal androgen pattern) correlates positively with musical ability. I think that correlation is likely a result of high prenatal androgen levels increasing spatial reasoning abilities; there is a relationship between spatial reasoning and musical ability. To my knowledge, there's only been one study of 2D:4D ratios of psychopaths, and what the researchers found was unexpected:
"The main research hypothesis predicts that 2D: 4D digit ratios will correlate negatively with psychopathy scores and positively with cognitive empathy scores. The study facilitates a withinâ€subjects correlational design, using a quasiâ€experimental method consisting of questionnaires and digit measurements. Fiftyâ€four participants volunteered and were gathered via purposive and convenience sampling. Each participant completed a selfâ€report psychopathy scale, a cognitive empathy test, a verbal IQ test and a scan of both hands. The scans were later measured and computed for digit ratios. Tâ€tests, multiple partial correlations and multiple regression found that, contrary to the research hypothesis, a higher level of preâ€natal oestrogen, as indicated by a larger 2D: 4D digit ratio, is a positive correlate of psychopathy in females, and a positive correlate of callous affect (psychopathy subâ€scale) in males, at less than 0.01 probability levels. Gender is also a correlate of psychopathy, as males scored significantly higher than females at 0.01 probability levels. This result sheds an interesting new light on the physiological correlates of psychopathy and the role that preâ€natal oestrogen plays in organisational effects on the brain during pre†and postâ€natal development." (Source)
When I was a teen I read you could have a musical face. I was very happy to have one. That is having a bigger distance between eye corner and corner of mouth on right side. I assume that is the same as this psychopathic face described. Now I realize a musical face is BS but I was really pleased back then. I am very musical though. I should dig out a photo of my psychopathic cousin to see his face. I don't remember right off if he has any facial assymetries. While we're at it, aspies are supposed to have a slightly smaller midface, but I never figured out how to measure that. How about testosterone hand (ring finger longer than index) which is aspie/psychopath especially in females? Interesting or not?