The evolutionary psychology of attraction and personality types: r/K selected mating strategies according to subsistence economy

Evolutionary psychologists have been pointing out the problems with our monogamous laws do not correspond to the more promiscuous human nature. The biggest problem, however, has been explaining the variation in human behavior, as some people are clearly more monogamous than others.

So, instead of assuming one monolithic human nature it makes more sense to investigate mating strategies by personality type. Helen Fisher has just done that (quite successfully IMHO), and found out that there are four personality groups and three preference strategies: builders (traditional, family-oriented), explorers (freedom-loving) - both of who prefer to find partners within their respective groups - and directors and negotiators who prefer to bond with each other. Whereas Helen Fisher thinks that these personality types have been present more or less equally since early humans arrived on the scene, I think that their “genotypes” have been predominant in accordance with a  particular subsistence economy.

Hunter-gatherers are usually highly monogamous. Sexual dimorphism (a sign of promiscuity) is largely diminished among hunter-gatherers, both compared to early human ancestors and modern societies (e.g exaggeration of secondary sexual features and digit ratio.

With increasingly longer onset of puberty (K selection), hunter-gatherers needed increased parental investment, not only maternal but also paternal and from relatives (grandmother hypothesis) and friends (alloparenting, see Sarah Hrdy). So, monogamy became the norm, making our ancestors more similar to penguins than our close ape relatives, as far as mating strategy is concerned. 

With the advent of farming and pastoralism status could be acquired with the accumulation of more material reproductive resources polygamy started to creep in (which might have been in both male and female interests). As there was less paternal insecurity among farmers, early farming societies actively tried to discourage polygamy (e.g. code of Hammurabi), which made pastoralist societies the ones with the highest degree of polygamy.

The following personality types correspond well with Helen Fisher's types (as well as Myers-Briggs types):

Farmers prefer the traditional type of family we know from the Romans, with the pater familias as the head. Hunter-gatherers prefer more “equal partners”.

hunter-gatherers	farmers	pastoralists
Late-onset of puberty	average onset of puberty	Early-onset of puberty
Tendency towards monogamy; increasing status doesn’t change that much	Tendency towards monogamy; gets lost with increasing status	Tendency towards polygamy
Look for: soulmates	Look for: helpmate	Look for: playmates
Difficulties in finding partners and reluctant to have children in a competitive society	Mostly still  want to get married and have children once they have reached the desired status	Reluctant to get married and have children when there are so many options in modern life
High divorce rates due to partner mismatch and/or prioritizing self-actualization	Lower divorce rates	High divorce rates due to promiscuous tendencies
More egalitarian	more status-oriented	more status-oriented
Out-group social	More In-group social	More In-group social
Often dislike routine, playful and imaginative	Love routine, industrious	Dislike routine, artful

From the first row, it can be inferred that the respective mating strategies are r/K selected and it is therefore not surprising that pastoralists are the least whereas hunter-gatherers are the most monogamous strategy. 

Farmer is the majority personality type and they are also the most adapted to our capitalist society (love routine and 9-5 jobs, making a career, etc.) and are the group of people who are most likely to start a family. Farmer women are the most likely to sacrifice a career to have children.

Pastoralists are freedom-loving and find it hardest to commit. They start early and often change partners in their teenage cliques. They often do settle down once they have children, however. Some, like Donald Trump and Hugh Hefner, might never do, though.

Hunter-gather mating strategies can widely vary. They represent the smallest percentage in society and therefore find it hardest to find a matching partner. Extroverted individuals may be very promiscuous until they find their soulmate and then become very monogamous. Introverted hunter-gatherers find it even harder to find a soulmate and might prefer to stay celibate if they can’t find a partner. In general, hunter-gatherers strive for a high degree of self-actualization (e.g. becoming a scientist) before settling down. They tend to be the last ones to have children among their peers. Once hunter-gatherers have found each other they tend to be very monogamous and not even high status may come in between (examples: Mark Zuckerberg, Bill Gates).  

When it comes to online-dating, hunter-gatherers are over-represented as it is hardest for them to find their "soulmates" and online-dating might actually have the advantage of getting somebody to know on a deeper level than real-life dating. For farmers, it is the exact opposite, online dating has little to offer to them as far as their prospective mates are concerned. 

The three types have not only distinct personalities but also distinct facial features, most probably due to within-group sexual selection.

Hunter-gatherers: rectangular face shape for hunters, heart-shaped face for gatherers (male and female patterns are often reversed in modern hunter-gatherer personalities, i.e. females can have rectangular facial shape and males the heart-shaped form. They, therefore, tend to pair in all possible varieties: hunter-gatherer, hunter-hunter and gatherer-gatherer.

San hunter (rectangular face) and gatherer (heart-shaped face) 

Richard Dawkins (hunter) and Lala Ward (gatherer) paring, two soulmates

Pastoralists have oval-shaped faces.

Datoga and Maasai pastoralists: oval faces.

Paul and Linda McCartney: oval faces, artistic personality types (ISFPs), two playmates, a turbulent but successful marriage.

Farmer types tend to be more serious and hard-working. They have typically square or round faces:

African farmers with square/round faces

Geroge W. and Laura Bush, square/round farmer faces

Dedicated to Helen Fisher and Sarah Hrdy, whose ideas have inspired this blog post. 

Credit for discovering the relationship between facial features and personality type goes to Jim Black