Before we tackle this question, let’s review some fundamental concepts of evolutionary biology and psychology. You need to have an understanding of these concepts before proceeding and if you’re already familiar with them a nice little review won’t hurt.
Reproductive potential
Reproductive potential
It’s the number of children an individual organism can produce. In humans, males have a higher reproductive potential than females because they produce much more sperm in their lifetime than females produce eggs.
Reproductive certainty
While males have a higher reproductive potential, females have a higher reproductive certainty. This means that almost all females reproduce whereas a lot of men do not get a chance to reproduce at all.
Reproductive success
Our psychological mechanisms are wired to seek reproductive success i.e. successfully passing on as many genes to the next generation as possible (having kids who can successfully reproduce).
Keeping these concepts in mind, let’s delve into the eternal question of whether human parents prefer sons or daughters…
More sons = greater reproductive potential
Since human males have a very high reproductive potential compared to females, having more sons means more of your genes have the chance of making it to the next generation.
When it comes to reproductive success, more is better. Having a head start is always preferred. If conditions turn out bad later and some genes die, others can survive.
Therefore, in general, parents tend to prefer sons over daughters under average circumstances.
What exactly do I mean by ‘average circumstances’?
Average circumstances mean that the factors that influence reproductive success are not extreme.
Now, there are a lot of variables that can influence reproductive success but the most important of them all is ‘availability of resources’.
Now, there are a lot of variables that can influence reproductive success but the most important of them all is ‘availability of resources’.
Hence, in this case, ‘average circumstances’ would mean that the resources that parents can invest in their children are neither large nor small, they’re average.
What if the resources are not average? What if the parents have less or more available resources? Will that affect their preference for sons versus daughters?
The answer is yes.
When available resources are meager
Reproductive success is both a function of reproductive potential and reproductive certainty. It’s just that under average circumstances, reproductive potential becomes more important because there’s already a good degree of reproductive certainty.
But when the available resources are meager, the balance of the equation shifts. Now, reproductive certainty becomes more important. In other words, when available resources are less, reproductive certainty becomes a more important determinant of reproductive success.
As you might have guessed, in such a situation daughters become more preferable than sons.
When you don’t have a lot of resources to invest, you can’t run the risk of producing sons whose reproductive certainty is low compared to daughters. They may not get a chance to reproduce at all, especially when their parents can invest very little in them.
There is a direct relationship between the reproductive success of males and their resourcefulness.
Therefore, when there’s a resource constraint, parents can’t simply go for the possibility of passing on a greater number of genes to the next generation. They’ve got to aim just for certainty. Beggars can’t be choosers.
It isn’t surprising, therefore, that women without a long-term partner or married to low-status men tend to produce an excess of daughters while women married into resourceful families tend to produce an excess of sons.
The logical conclusion that we can make from all that we’ve discussed above is that parents who have slightly more than average resources should show no preference towards either boys or girls. They should prefer boys and girls equally.
However, should economic conditions worsen, they’re likely to prefer girls over boys.
An interesting study conducted by researchers from two business schools showed that parents who had both daughters and sons spent more on daughters in bad economic times.
These parents seemed to unconsciously understand that in tough economic conditions reproductive certainty became more important than higher reproductive potential.
Even more intriguing is the fact that such preferences also exist at the womb level. When resources are scarce, female biology suppresses boys’ survival in the womb. The result being that mothers give birth to fewer males than normal.
These parents seemed to unconsciously understand that in tough economic conditions reproductive certainty became more important than higher reproductive potential.
Even more intriguing is the fact that such preferences also exist at the womb level. When resources are scarce, female biology suppresses boys’ survival in the womb. The result being that mothers give birth to fewer males than normal.
Here’s a short video discussing this…
References:
Cameron, E. Z., & Dalerum, F. (2009). A Trivers-Willard effect in contemporary humans: male-biased sex ratios among billionaires. PLoS One, 4(1), e4195.
Durante, K. M., Griskevicius, V., Redden, J. P., & White, A. E. (2015). Spending on daughters versus sons in economic recessions. Journal of Consumer Research, ucv023.
Chimps frequently patrol the borders of their territory, sometimes raiding, attacking or even killing their neighbors.Conclusion To summarize, engaging in a war has the potential of providing men with huge benefits in terms of resources and reproductive success but in order to motivate them to go to war, the huge costs associated with war have to be reduced.If you look at history, men have created all kinds of expansionist ideologies and under the guise of fighting for or defending their ideologies, all they actually ever fought for was land, power, resources and women.References:Why do chimps kill each other?More males mean more territory patrols, study shows
Male elephant seals engaged in a bloody combat.In humans, intrasexual competition among the males throughout our evolutionary history has been quite similar to that seen in elephant seals.Since human females invest more heavily in the offspring, they’re a valuable limiting resource on reproduction for males. Males are constrained in their reproduction by their ability to gain sexual access to high-investing females.This sex difference in minimum obligatory parental investment means that males can produce more offspring than females can. This difference leads to a different reproductive variance of males and females. Reproductive variance simply means how varying your chances of reproduction are.While most human females reproduce sooner or later (since they invest a lot and so are in demand), men can be totally denied a chance to pass on their genes. This is what is meant by ‘high reproductive variance’ of human males. Consequences of a high reproductive varianceHigh reproductive variance in men leads to riskier strategies for securing reproduction. The males that take more risks are more likely to be reproductively successful. Due to this, some males gain more than their ‘fair share’ of copulations, while other males are shut out entirely (like defeated male elephant seals).This leads to more ferocious competition within the high-variance sex. Polygyny, over evolutionary time, selects for risky strategies, including those that lead to violent combat with rivals and those that lead to increased risk taking to acquire the resources needed to attract members of the high-investing sex.This is why human males engage in a lot of violence with one another, even if it may have no direct bearing on their reproductive success in the given moment e.g. pre-pubescent boys wrestling with each other. This evolutionarily important behaviour has to be practised since childhood just as boxers practise a lot before the actual fight. Passing on one’s genes is an important matter biologically speaking, and therefore our psychology is evolved to ensure that we practise behaviors that contribute to our reproductive success in the future.Women, on the other hand, have nothing to gain by being violent but a lot to lose. Women need to place a higher value on their own lives than do men on theirs, given the fact that infants depend on maternal care more than on paternal care. Women’s evolved psychology, therefore, should reflect greater fearfulness of situations that pose a physical threat of bodily injury and avoidance of such situations as much as possible.Instead of violent physical aggression, women’s intrasexual competition manifests as gossiping, shunning the other person, spreading vicious rumours, breaking contact with the other person and befriending someone else.Also, as children and teens, women prefer more nurturing behaviours such as feeding and grooming their dolls or looking after other infants in the family than playing with guns and action hero figures.It’s all nothing but practice- practice of evolutionarily important things to come in the future.