Psychopaths, sociopaths, empaths and altruists

Abigail Marsh describes psychopaths and altruists as being on the opposite end of the fear spectrum in her highly recommendable book The Fear Factor: How One Emotion Connects Altruists, Psychopaths, and Everyone In-Between. It is a well-known fact that most psychopaths are quite fearless, but why would altruists be on on the other side of the spectrum?

In fact, both have got to do with life history or r/K selection.  According to scientists (e.g. Del Giudice Evolutionary Psychopathology) life history has a huge influence on personality traits, e.g. longer lifespans would entail later sexual maturity, more parental investment and less risky behaviour.  Life spans in our evolutionary past varied according to our ancestors' mode of subsistence.
There are many indications that for early farmers life was harder and probably shorter than those of hunter-gatherers, even though people in more modern agricultural societies live longer. There are also plenty of indications that pastoralists, who experience a lot of violence and instability had the shortest lifespans. It is likely that evolution entrenched adaptive traits genetically, e.g. farmers with higher levels of serotonin (conscientiousness and future-oriented planning) were more successful. For pastoralists, whose lives were shorter, taking risks (dopamine) would have been advantageous for survival and mating. For hunter-gatherers instead of risk-taking a childlike openness for learning in new environments and humbleness for a non-violent co-existence would have been the most advantageous personality traits. We get the following picture:
r/K theory and life history studies would predict the following traits (at least among males):
Shortest lifespan (pastoralist)
medium (farmer)
Long lifespan (HG)
Most risk-taking/least fearful
Least risk-taking/most fearful
Low empathy/low sensitivity
High empathy/high sensitivity
Earliest onset of puberty
Latest onset of puberty
Least paternal investment
Most paternal investment
Most sociosexual
Most pair-bonded
Higher sexual dimorphism
Lower sexual dimorphism
Most in-group social
Most out-group social/altruistic
An r-selected strategy would be dopamine dominant (novelty seeking), include earlier onset of puberty, higher display of sexual dimorphism and risk-taking, also in mating with different partners. A K-selected strategy includes a more cautious lifestyle, investment in parenting rather than investment in mating and display of fitness indicators (think of guys spending their time with their kids rather than working out in the gym).
How does altruism come into play? In accordance with Marsh, I believe that alloparenting has a lot to do with. Oxytocin has been shown to induce increased parenting behaviour in fathers and low levels of oxytocin decrease empathy. 
So, most psychopaths can be expected to be found in the pastoralist personality group (SP in MBTI). Of course, that does not mean that pastoralist personality types are psychopaths, only very extreme cases. This fits well with the observations that many psychopaths can frequently be found among entrepreneurs, business people, policemen and surprisingly also chefs, all common occupations for ESTP personality types in MBTI.  
However, there is a type of psychopath that does not fit into this picture: sociopaths. Here are some of the common differences:

Psychopath (pastoralist type)
Sociopath (hunter-gatherer type)
Mostly genetic
Mostly early childhood adversity
Proactively aggressive
Reactively aggressive
Feel no remorse
Feel remorse
Can’t recognize fear in others
recognize fear in others
have often normal lives
are often outsiders
Social anxiety
Sociopaths can most frequently be found at the opposite end of the fear spectrum, among hunter-gatherer personalities. These are often very sensitive and empathic kids (in accordance with a K strategy) who develop ODD (oppositional defiant disorder) in reaction to being forced to do “farmer chores”, like going to school. Having hunter-gatherer minds and often suffering from ADHD such routine tasks don’t come easy to them. In primary school, my gifted son would rather cry for an hour instead of doing his homework, which he could have done in a few minutes. It is very hard to explain such “irrational behaviour” otherwise.

Even for adult hunter-gatherer personality types, it is hard to hold a 9-5 job, and many of the kids who develop ODD never get far enough in school to be able to do anything else but a routine job. So they are caught in a vicious circle. With a lot of understanding and the right programmes, I suppose it would be much easier to re-socialize sociopaths than psychopaths who have become delinquent.