More fun base-rate reasoning: psychopaths make up 1-2% of the population, and most are great manipulators; the top 1% of the population IQ-wise is sometimes taken as being the genius fragment; even if we assume the 1% IQ are all gifted conversationalists, if all we know about someone is their gifted conversation, we wind up inferring that they are equally or more likely to be a psychopath than a genius!
I’m actually somewhat curious about the degree overlap between those two groups.
Well, assuming complete independence would just be 1% 1%; but there does seem to be a slight negative correlation between psychopathy & IQ. Complicating matters is Hare and Babiak’s research into business psychopaths, where they estimate they are over-represented by a factor of 2-3 or so, suggesting that the negative correlation may be skewed by the ‘failures’ in prison samples (which are the samples for most studies, for obvious reasons); smarter psychopaths are far less likely to resort to violence\*, further hindering identification (since impulsive violence is one of the major diagnostic hallmarks). To the extent that the gifted 1% avoid business, that may restore a negative correlation / underepresentation. Finally, psychopath’s impulsivity and few long-range goals or efforts (another part of the diagnosis along with glibness/manipulation) suggests that to the extent genuine objective achievements cause you to be considered a gifted 1%, we can expect still more underrepresentation*.
So guesstimating further, I’d say in a population of 300m people (eg. the US), we could expect substantially fewer than 30,000 gifted psychopaths (0.01 0.01 300,000,000). Phew!
On the other hand, they would be the ones who would do the most damage and be least likely to ever be diagnosed, so we may never know for sure...
* Which makes me wonder about high IQ societies, now that I think about it. My vague impression was that they tend to collect those with poor social skills, and also with fewer objective accomplishments & success. So if you meet someone in a high IQ societies who seems very charming and empathetic but lacks objective accomplishments, just how much does this increase the psychopath possibility over the 1% base rate..? ** Covered multiple times in the Handbook; first relevant paper seems to be “Psychopathy and Aggression”, Porter & Woodworth.
I’m actually somewhat curious about the degree overlap between those two groups.
Well, assuming complete independence would just be 1% 1%; but there does seem to be a slight negative correlation between psychopathy & IQ. Complicating matters is Hare and Babiak’s research into business psychopaths, where they estimate they are over-represented by a factor of 2-3 or so, suggesting that the negative correlation may be skewed by the ‘failures’ in prison samples (which are the samples for most studies, for obvious reasons); smarter psychopaths are far less likely to resort to violence\*, further hindering identification (since impulsive violence is one of the major diagnostic hallmarks). To the extent that the gifted 1% avoid business, that may restore a negative correlation / underepresentation. Finally, psychopath’s impulsivity and few long-range goals or efforts (another part of the diagnosis along with glibness/manipulation) suggests that to the extent genuine objective achievements cause you to be considered a gifted 1%, we can expect still more underrepresentation*.
So guesstimating further, I’d say in a population of 300m people (eg. the US), we could expect substantially fewer than 30,000 gifted psychopaths (0.01 0.01 300,000,000). Phew!
On the other hand, they would be the ones who would do the most damage and be least likely to ever be diagnosed, so we may never know for sure...
* Which makes me wonder about high IQ societies, now that I think about it. My vague impression was that they tend to collect those with poor social skills, and also with fewer objective accomplishments & success. So if you meet someone in a high IQ societies who seems very charming and empathetic but lacks objective accomplishments, just how much does this increase the psychopath possibility over the 1% base rate..?
** Covered multiple times in the Handbook; first relevant paper seems to be “Psychopathy and Aggression”, Porter & Woodworth.