In pre-industrial societies, the highest status men typically had the most wives and the largest number of children. In the East they were the emperors and sultans who had several official wives in addition to large harems. In the West, they were the kings and other rulers who had wives in addition to numbers of concubines and mistresses. The result was often large numbers of children, both legitimate and not so.1 In case you are wondering, the man on record with the most number of children is Ismail the Bloodthirsty, ruler of Morocco in the seventeenth century and probably not a nice guy, who had at least 800 children.2 The complete total is not known, because after a while the girls were not counted. DNA evidence also shows that old-time conquerors, such as Charlemagne in Europe and Genghis Khan in Asia, may have given Ismail some competition, as both have been remarkably successful at bequeathing their genes to subsequent generations.
As societies have industrialized, the trend has been for people to produce fewer offspring. We are WEIRD: Western, educated, from industrialized, rich, and democratic countries, and WEIRD people don’t do the things that they did in pre-industrial societies. They don’t have large families. High status men don’t have multiple wives and many children.
Or do they? Evolutionists have often wondered about this, because evolutionary theory suggests that high social status in most species (including humans) translates into larger numbers of offspring. Yet time and time again, census figures show that women in the richest households in advanced industrial societies have fewer children than women in the poorest households. 3 Some evolutionists have concluded that even though our bodies and psyches may have evolved, those evolved psyches have not adapted to the novel conditions of our brave new world of post-industrial societies, and the results are, frankly, maladaptive. There have been some scholars who dispute this – those who note that, among other problems, census studies only look at female fertility, not male fertility, which is after all, more difficult to measure. But they have been the minority. Looking around, people see poor women with lots of children, and rich women with few children, so the inverse relationship between status and fertility has been generally accepted.
Yet new research supports the holdouts. For men at least, some kinds of social status (e.g. personal earnings) are positively associated with number of biological offspring.4 Census and other surveys usually only examine women’s fertility or the number of children in the household, and many social surveys do not distinguish between children that are the biological offspring of the adults in the family from other children in the household. But registry data in Europe that follows all individuals throughout their lives is a great source of information on both male and female fertility, and it shows that at least for men – high status does translate into more children.5 In the U.S., occasionally good data on male fertility are also collected, and this data also shows the same thing. 6
The results of this research actually show an interesting Anglo versus European split in the type of personal status that translates into more children. In the Anglo countries (U.K and the U.S.) it is just high income that translates into more offspring for men, as wealthier men have more biological children than low-income men. In the U.S. and U.K. highly educated men have fewer children than poorly educated men. In continental Europe, it is often not men with more money who have more children than less well to do men, but better educated men also.
How do these results make sense in light of the U.S. census data that show that poorer households have more children than richer households, on average? The research suggests that the primary mechanism by which better earning men have more children than low earning men is because low earning men are more likely to remain childless.7 So the low earning men don’t have any children at all. They may not even be included in census or survey data, as they are more likely than low income women to be in jail, homeless, in some kind of institution, or in the military.
Further, household income is a composite of the money earned by all earners in the household. In poorer households, there is usually just one earner – the mother – and her earnings are often low. In richer households, there may be two or more earners. Yet when the woman earns a lot of money, she tends to have fewer children. When the man earns a lot of money, he tends to have more children. How does he do that? A high income man can afford a wife who doesn’t work, and can stay home to take care of children. Alternatively, if there is a divorce, high income men are more likely to remarry, and more likely to have children with a subsequent wife6. But this is of course in a new household, as the kids from the first marriage usually stay with their mother. Put all these trends together and the result is that higher income households have fewer children than lower income households, on average.
The research also shows that high income women have fewer children on average than low income men in all countries. WEIRD sexism? Perhaps not. When you look at pre-industrial societies, high status women (the daughters of high status families) often didn’t have that many children either. Some ended up in convents, some had to kill themselves after the death of their husbands, and some even were killed at birth. Some didn’t get married at all 8. Some had time on their hands and wrote novels. The first novel ever written, The Tale of Genji, is credited to a Japanese noblewoman in the tenth century, who was widowed early in her life, and had only one child.
Donald Trump, as he often tells us, is a rich man. He has had three wives in sequence, each wife being younger than the previous one. With these wives he has had five children, but like many rich and prominent men, he may have had others we don’t know about. Even so, five children is well above the U.S. average. His wives – all high status women – have not had as many children as he has. Perhaps he is not as WEIRD as we think. In fact, he has done the things that high status men in all societies have always done. Now he wants to be president of the U.S. – leader of our country. That is another thing that high status men have always done – vied for political leadership. Plus ça change, plus c’est la même chose? Let’s hope future DNA studies don’t show a lot of Trump genes in the population.
- Betzig (1986). See also Table 1 in Hopcroft (2006).
- For the U.S., see Dye (2008)
- For the U.S., see Hopcroft (2006, 2015); for Sweden, see Fieder and Huber (2007); for the U.K., see Nettle and Pollet (2008); for the Netherlands, see Table 4 in Kaptijn et. al. (2010); for Norway, see Figure 2, Lappegård and Rønsen (2013); see also Stulp and Barrett (2016) for a review.
- For example, the Swedish registry collects information on all individuals living in Sweden including their name, personal identity number, place of birth, citizenship, spouse, children, parents, guardian(s) and adoption, death and place of burial.
- For example, see the data sets used in Hopcroft (2006) and (2015).
- See Fieder and Huber (2007); Hopcroft (2015).
- See Jokela al. (2010); Lappegård and Rønsen (2013)
- See Dickemann (1979); Boone (1986); Hrdy 2000.
Betzig, L. 1986. Despotism and Differential Reproduction: A Darwinian View of History. New York: Aldine.
Boone, James L. 1986. “Parental investment and elite family structure in preindustrial states: A case study of late medieval-early modern Portuguese geneologies.” American Anthropologist 88:859-78.
Dickemann, Mildred. 1979. “The ecology of mating systems in hypergynous dowry societies.” Social Science Information 1979 18: 163
Dye, J. L. 2008. Fertility of American Women: June 2008, Current Population Reports, P20-563, U.S. Census Bureau, Washington, DC.
Fieder, M., and S. Huber. 2007. “The effects of sex and childlessness on the association between status and reproductive output in modern society.” Evolution and Human Behavior 28:392–398.
Hopcroft, R. L. 2006. “Sex, status and reproductive success in the contemporary U.S.” Evolution and Human Behavior 27: 104-120.
Hopcroft, Rosemary L. 2015. “Sex differences in the relationship between status and number of offspring in the contemporary U.S.” Evolution and Human Behavior 36, 2:146–151.
Hrdy, S.B., 2000. Mother nature: Maternal instincts and how they shape the human species. Ballantine Books.
Jokela, Markus, Anna Rotkirch, Ian J. Rickard, Jenni Pettay and Virpi Lummaa. 2010. “Serial monogamy increases reproductive success in men but not in women.” Behavioral Ecology 21: 906-912.
Kaptijn, Ralf, Fleur Thomesea, Theo G. van Tilburga, Aart C. Liefbroera,b, Dorly J.H. Deega. 2010. “Low fertility in contemporary humans and the mate value of their children: sex-specific effects on social status indicators.” Evolution and Human Behavior 31: 59–68.
Lappegård, T. and Rønsen, M. 2013. “Socioeconomic Differences in Multipartner Fertility Among Norwegian Men.” Demography 50:1135–1153.
Nettle, Daniel and Thomas V. Pollet. 2008. “Natural Selection on Male Wealth in Humans.” The American Naturalist 172, 5: 658-666.
Stulp, Gert, and Louise Barrett. 2016. “Wealth, fertility and adaptive behaviour in industrial populations.” Phil. Trans. R. Soc. B 371, no. 1692: 20150153.