The majority of males who reach adolescence will become fathers. While their immediate interests may be guided by status and sexual concerns, they may be laying the groundwork for subsequent reproductive success. Garnering a good hunting reputation or job may pave the way to a long-term relationship and children. But what about the guys who don’t become dads? How commonly have men ended their lives childless, in small-scale societies and in today’s wider world? What are some of the reasons why men might be non-dads?
Across human societies, males tend to have higher variance in reproductive success than females. In other words, male reproductive output (e.g., number of kids) tends to be more variable than female reproductive output. That overarching pattern is consistent with sexual selection pressures operating more stringently on males. It can leave a set of males childless. Of course, there are other considerations behind that pattern. Males have higher variance in reproductive success in serial monogamous and polygynous societies but not ones practicing more strict social monogamy. The extremes of male reproductive skew can be found in some past despotic societies, in which the elite of the elite males had lots of kids (perhaps with lots of concubines and multiple wives) while plenty of other men had few or none. Think of the Incan empire at the time of Spanish contact or various societal depictions in the Old Testament.
To provide some more specific data on non-dads, among the Dogon of Mali only two of 44 men whose lifetime reproductive success was tabulated had no children. Among Aka foragers of Central African Republic, only one man of 29 had no children. From Hadza demographic data, about 15% of some 45 men with completed fertility schedules did not have any reported children. Among the Chimbu of highland New Guinea, Kent Flannery and Joyce Marcus report in their book “The Creation of Inequality” that, “About 15 percent of the population wound up as unproductive “rubbish men” who attached themselves to Big Men as errand boys. Many rubbish men never married, because their kinsmen considered them such losers that they would not contribute to their purchase of a wife. Ordinary men, usually monogamous and at least minimally involved in trade, made up 70 percent of the population. The remaining 15 percent were Big Men, who averaged between two and three wives and were very successful at trade, controlling almost all the valuables referred to colloquially as “shell money.”” (p. 101)
This Chimbu case also points to some of the reasons why some men might be non-dads: they may not have garnered the status and resources that made them viable long-term mates and fathers. The Chimbu non-dads were apparently the men who occupied the tail end of a statistical distribution. Of course, we can imagine other reasons why men in other societies become non-dads. Men might be killed before having the opportunity to have children. An adolescent male engaging in risky foraging strategies in the quest for status could instead meet his grave, dying childless. Young men fighting with each other over status in reproductive contexts could fall victim to the selective embrace of a love triangle, also dying childless. Enemies from other groups might have motivated some men to head-hunting, but their own heads might be taken instead. If those seem like dramatic ways to die as a non-dad, they are reasonable inferences from ethnographic studies, like those reported in Flannery and Marcus’ book, and also align with the idea that males strive for the status that makes them eligible mates, even if it results in deaths along that path. Add to that cases in which some men lived as non-reproductive adults—as among “two-spirits” in many Native American societies—and we find another means by which men might remain childless.
In today’s world, these views of non-dads may seem remote. The challenges of garnering an education and having the desired resources to have long-term fertile unions are considerable. Men and women alike may delay childbearing and have fewer, or no kids, as a result. More men than our foraging forebears could have imagined opt out, intentionally, of fatherhood altogether. Perhaps, too, infertility or other medical problems leave men without genetic children, even when the desire to have them exists. In a large study of Australians, 13% of men aged 45-59 were childless, which was higher than the rate among similarly aged women (10%). Furthermore, Australian men in high status occupations were more likely to be in partnerships, which in turn was associated with a reduced likelihood of being childless. Those Australian findings also have a parallel in the U.K., in which men’s wealth was inversely related to the likelihood being childless. Thus, the social standing men garner through work impacts reproductive outcomes, linkages that suggest selection continues to operate on men. Not all men become fathers.
Betzig, L. (2012). Means, variances, and ranges in reproductive success: comparative evidence. Evolution and Human Behavior, 33, 309-317.
Brown, G. R., Laland, K. N., & Borgerhoff-Mulder, M. (2009). Bateman’s principles and human sex roles. Trends in Ecology and Evolution, 24, 297-304.
Blurton Jones, N. http://www.anthro.ucla.edu/people/faculty?lid=1133
Flannery, K., & Marcus, J. (2012). The creation of inequality: How our prehistoric ancestors set the stage for monarchy, slavery, and empire. Cambridge: Harvard University Press.
Nettle, D., & Pollet, T. V. (2008). Natural selection on male wealth in humans. The American Naturalist, 172, 658-666.
Parr, N. (2010). Childlessness among men in Australia. Population Research and Policy Review, 29, 319-338.