Why evolutionary psychologists have fewer offspring

First off, full disclosure I am a big fan of evolutionary psychology. Evolutionary psychology has been criticized for a wide variety of reasons. Most of which I personally find are pseudo-arguments. One criticism the proponents of EP have never been able to address satisfactorily,  the elephant in the room: why do evolutionary psychologists have few or no offspring, when all life is programmed to procreate. Evolutionary psychologists might be quite successful professionally, but not from the very point of view of evolutionary psychology itself.

When I read Steven Pinker’s “tell our genes to go jump in the lake” I was petrified. Evolution can do a lot of things to genes, but it cannot program them to voluntarily forfeit reproduction. I was sure that must be an explanation, but Pinker’s statement contradicted the whole idea of evolutionary psychology itself.

Steven Pinker isn’t the only childless evolutionary psychologist. When googling I wasn’t able to find offspring for Leda Cosmides and John Tooby (the founders of EP) or Robin Dunbar (famous for Dunbar’s number), either.  Helen Fisher, the world's learning expert on love, doesn't have children. Geoffrey Miller and his wife Diana Fleischman (both evolutionary psychologists) talk a lot about polyamory online, but it looks like polyamory doesn’t produce offspring in modern times either.

Richard Dawkins (strictly speaking not an evolutionary psychologist, but as he writes a lot about human religious evolution he is included here) has only one daughter.  Evolutionarily speaking he has only passed on half of his genome. Doesn’t that make an eminent scientist and writer rather less successful in evolutionary terms?

What’s going on here? Was evolutionary psychology only true for our past? Of course, not, but it seems that evolutionary psychologists are living paradoxes: they preach that the ultimate goal is reproduction and don’t do it themselves. They claim that altruism isn’t real, and in a way, they are altruistic themselves: like worker bees they forgo personal reproduction to serve society (they do, no sarcasm intended).

In fact, they aren’t alone. University professors in general (female professors in particular) seem to have fewer offspring. How come?  A simple explanation would be that they simply sacrifice their offspring in favour of their career, but that isn’t the whole story.

Markus Jokela (2012) has found in a study that since the availability of the pill

Higher levels of openness to experience in both sexes and higher levels of conscientiousness in women were associated with lower fertility [...]

Higher levels of openness and conscientiousness is exactly the typical personality profile for university professors and scientists. Unfortunately, Jokela doesn’t offer an explanation, so I will offer my own here: university professors - in contrast to the majority of people - have typical hunter-gatherer minds. I.e., they have inherited more hunter-gatherer genes than most people, who have inherited more farmer genes. Typical traits for each

Hunter-gatherer types	farmer types
High on personality trait “openness” novelty-seeking (intellectual)	low on “openness”(but high on conscientiousness), routine-loving
Strongly (actively) egalitarian, idealistic	Status-seeking, materialistic
Tendency towards out-group sociality, more accepting of diversity (e.g.  different sexuality, refugees, etc.)	Tendency towards in-group sociality (identifies more strongly with a core group, like family, religious group or sports team)
More liberal ideology	More conservative ideology
Less sexual dimorphism	More (display of) sexual dimorphism
Later onset of puberty	Earlier onset of puberty
Tendency to wanting fewer children	Tendency to wanting more children
Less interest in small-talk and gossip	Higher interest in small-talk and gossip

To understand why hunter-gatherer types want fewer children, it is important to understand their life-history model. Hunter-gatherer lived longer than early farmers and therefore had later puberty as well as fewer children during their lifetime (about half as many as farmers), as they typically reproduced only about every four years (vs two years for farmers).

Moreover, hunter-gatherers practice alloparenting, which makes it even harder for modern hunter-gatherer types to have children due to a lack of social support. I suppose the majority of cases of post-partum depression occurs in hunter-gatherer types. Finally, the trait conscientiousness, which was originally a farmer trait, inherited by a part of the hunter-gatherer population, seems to have opposites effects in farmer types vs hunter-gatherer types: farmer types who are financially successful typically have more offspring than the average population, whereas hunter-gatherer types who are more conscientious (also more ambitious and driven) have fewer offspring than those who aren’t, as they put their careers and self-actualization over their private lives.

To sum up, hunter-gatherer types have fewer offspring because:

• Hunter-gatherers are genetically programmed to have fewer offspring than farmers
• Hunter-gatherers rely more on social support (alloparenting) than farmers
• High levels of ambitiousness have negative effects on the number of offspring as opposed to farmer types