Friday, April 29, 2011

The eternal infant

“A chimpanzee’s ability to learn is drastically reduced upon reaching maturity. But baby chimps will eagerly mimic a human caretaker – sticking out their tongues, opening their mouth wide, or making their best effort at a kissy face.” (Geoff, 2009)

A newborn creature will spend much time exploring its environment. As it comes to know its surroundings, it no longer has to acquire new information at the same rate. It loses its ability to learn.

We humans are different. We never grow up. As adults, we retain this infant-like mental plasticity, much in the same way as a child’s tolerance for milk persists into adulthood in dairy-farming societies.

Geneticists are now a step closer to understanding this evolutionary change. A team led by David Kingsley of Stanford has shown that ancestral humans lost a key piece of DNA that switches on GADD45G, a gene that stifles growth of brain tissue. In non-humans, this gene regulator slows down the growth of brain tissue:


The GADD45G regulator was active in layers of the brain where cells that ultimately form the cortex are born. Specifically, in mice and chimps, GADD45G suppresses the development of brain regions which in humans are involved in higher cognitive functions like conscious thought and language."

Completely losing GADD45G would be like losing the brakes," says Kingsley. That happens in pituitary tumours when the regulator fails and cells grow without restraint, but in healthy humans the regulatory change would have only decreased activity in specific brain areas, causing them to grow larger.
(Coghlan, 2011; see also McLean et al., 2011)

This kind of genetic change may largely explain how the brain progressively expanded in ancestral humans. And this evolution did not stop with the advent of Homo sapiens. Human populations today vary at several gene loci that regulate brain growth: ASPM, MCPH1, CDK5RAP2, and CENPJ. At these loci, the most recent alleles likewise seem to favor brain growth by allowing each cortical column of neurons to expand outward over a longer period of time. Interestingly, the main result does not seem to be higher IQ, but rather some other, still unknown, enhancement of mental capacity (Frost, 2008; Montgomery & Mundy, 2010; Rimol et al., 2010; Wang et al., 2008).

Differences in mental capacity should thus steadily increase from infancy to adulthood. This is an important point. If young children perform equally well on a mental task, it is often assumed that later differences must be due to differences in the learning environment.

References

Coghlan, A. (2011). Key to humanity is in missing DNA, New Scientist, March 9http://www.newscientist.com/article/mg20928033.500-key-to-humanity-is-in-missing-dna.html

Frost, P. (2008). The spread of alphabetical writing may have favored the latest variant of the ASPM gene, Medical Hypotheses, 70, 17-20.

Geoff. (2009). Chimpanzees and Neoteny, March 30.
http://www.gmilburn.ca/2009/03/30/chimpanzees-and-neoteny/

McLean, C., Reno, P., Pollen, A., Bassan, A., Capellini, T., Guenther, C., Indjeian, V., Lim, X., Menke, D., Schaar, B., Wenger, A., Bejerano, G., & Kingsley, D. (2011). Human-specific loss of regulatory DNA and the evolution of human-specific traits, Nature, 471 (7337), 216-219 DOI: 10.1038/nature09774

Montgomery, S.H. and N.I. Mundy. (2010). Brain Evolution : Microcephaly genes weigh in, Current Biology, 20(5), R244

Rimol, L.M., I. Agartz, S. Djurovic, A.A. Brown, J.C. Roddey, A.K. Kähler, M. Mattingsdal, L. Athanasiu, A.H. Joyner, N.J. Schork, et al. for the Alzheimer’s Disease Neuroimaging Initiative (2010). Sex-dependent association of common variants of microcephaly genes with brain structure. Proceedings of the National Academy of Science. USA, 107, 384–388.

Wang, J.K., Li, Y., and Su, B. (2008). A common SNP of MCPH1 is associated with cranial volume variation in Chinese population. Human Molecular Genetics, 17, 1329–1335.

Friday, April 22, 2011

The fast runners of evolution


In the deer family, genetic variability is greater within some species than between some genera. Does Fst tell us what we think it tells us?

At almost any genetic marker (blood types, serum proteins, enzymes, mtDNA, etc.), a typical gene varies much more within than between human populations. And this is true not only for large continental populations but also for small local ones. The geneticist Richard Lewontin found that 85% of our genetic variation exists among individuals and only 15% between ‘races.’ He concluded:


It is clear that our perception of relatively large differences between human races and subgroups, as compared to the variation within these groups, is indeed a biased perception and that, based on randomly chosen genetic differences, human races and populations are remarkably similar to each other, with the largest part by far of human variation being accounted for by the differences between individuals. (Lewontin, 1972)


Was Lewontin right? Some geneticists have remained unconvinced, their doubts focusing on three points:

1. A small genetic difference can still make a big cultural difference

Even if human populations differ only slightly at certain gene loci, these slight differences can still have big effects.

For instance, the historical economist Gregory Clark has argued that the slow but steady demographic expansion of the English middle class from the 12th century onward gradually raised the population mean for predispositions to non-violence, deferment of pleasure, and other future-oriented behavior. Although the nascent middle class was initially a small minority in medieval England, its descendants grew in number and gradually replaced the lower class through downward mobility. By the 1800s, its lineages accounted for most of the English population.

There then came the triumph of Victorian morality—a relatively sudden cultural change due to a genetic change that had slowly reached a point of critical mass. The English middle class could now impose its behavioral norms on the whole population, thereby abandoning the ‘two-tier morality’ of other class-stratified societies (Clark, 2007, pp. 124-129, 182-183; Clark, 2009).

2. Lewontin’s finding is true only if we look at one gene at a time

Genes vary much more within than between human populations only if we look at one gene at a time. The pattern reverses if we aggregate variation at several gene loci. The more we aggregate, the more the genetic variation will exist between populations and not within them. This point was first made by Cavalli-Sforza back in 1966 and later by Mitton (1977, 1978), Edwards (2003), and Sesardic (2010).

3. A big chunk of inter-individual genetic variation is actually intra-individual

Although only 15% of human genetic variation is composed of population differences, the remaining 85% is not necessarily between individuals. Since we are diploid organisms, some genetic variation is actually intra-individual—the differences between the genes you inherited from your mother and the genes you inherited from your father. If we factor out this kind of variation, population differences actually account for a third of all human genetic variation (Sarich and Miele, 2004).

How valid are these three points?

The first one was true historically and, presumably, prehistorically. A slight genetic advantage could indeed leverage very disproportionate benefits. “Winner takes all.” This kind of dynamic, however, is no longer legitimate in modern societies, at least not to the same extent. Although we accept that losers should lose, we don’t accept that they should lose everything. Our societies provide a wide array of redistributionist mechanisms to ensure that slight advantages don’t snowball into big ones.

The second point is certainly true. Clearly, two groups are easier to tell apart with several criteria than with one. With enough criteria, any overlap will shrink to zero and all individuals can be unambiguously assigned to either group. This is basic logic. But all this proves is that human populations are identifiable. It doesn’t prove that the differences between them are greater than the differences within them.

The third point invites the same reply of “So what?” If our intra-population variation is inflated by intra-individual variation, the same would be true for all species, and not just our own. Remove intra-individual variation, and you’ll certainly get a higher estimate of inter-population variation. But this will be true across the board. Human races will still look relatively unimportant.

In all this, a more fundamental criticism is being ignored. How meaningful is the ratio of inter-population to intra-population variation? Just what exactly does it tell us?

This ratio, called Fst, is not as meaningful as one might think:


Fst isn’t a good measure of genetic-phenotypic mediation. As a case example, Long and Kittles (2003) found a between human population Fst of 11% based on their sample; when they added chimpanzees, the between population Fst increased only to 18% [3]. Mountain and Risch (2004), citing this example, note that ‘‘a low FST estimate implies little about the degree to which genes contribute to between-group differences.’
(Occidentalist, 2011)


Indeed, some sibling species show the same kind of genetic overlap that we see between human races. And yet these species are anatomically, physiologically, and behaviorally distinct (Frost, 2008).

Remember, when two populations differentiate under the impact of diverging selection pressures, this differentiation concerns only a tiny fraction of the genome. Why? There are two reasons:

(a) Much genetic variation is of low selective value, often being little more than "junk" variability, and thus responds weakly to changes in selection pressure.

(b) Much genetic variation is equally adaptive in both of the new adaptive landscapes. There are many cases of genetic polymorphisms that widely occur not only among different populations of one species, but also among related species (Klein et al., 1998).

Fst cannot tell us how much populations really differ from each other within a species—and by ‘really’ we’re talking about adaptive differences that show up in anatomy, physiology, and behavior. It basically tells us how long these populations have been separated from each other, with some adjustment for ongoing gene flow. In our case, Fst tells us that human races are young, very young.

But this we know already. The past 40,000 years have seen our ancestors spread into a multitude of natural environments—from tropical rain forest to arctic tundra. And the past 10,000 years have seen humans enter an even greater variety of cultural and social environments—from simple horticulture to complex societies with class differentiation, State formation, urbanization, systematized religion, and the ability to store, accumulate, and exchange information via writing.

We also know that these same years have seen an accelerating pace of genetic change. Natural selection has altered at least 7% of our genome over the last 40,000 years. In particular, the speed of genetic change rose over a hundred-fold with the advent of agriculture some 10,000 years ago (Hawks et al., 2007).

The correlation is very weak between the passage of time and the degree of evolutionary change. Some organisms have remained virtually the same for millions of years. Others have changed very quickly. We, humans, are the fast runners of evolution.

References

Cavalli-Sforza, L.L. (1966). Population Structure and Human Evolution, Proceedings of the Royal Society of London. Series B, Biological Sciences, 164, 362-379.

Cavalli-Sforza, L.L., P. Menozzi, and A. Piazzi. (1994). The History and Geography of Human Genes, Princeton: Princeton University Press.

Clark, G. (2007). A Farewell to Alms. A Brief Economic History of the World, Princeton University Press, Princeton and Oxford.

Clark, G. (n.d.). The indicted and the wealthy: surnames, reproductive success, genetic selection and social class in pre-industrial England,
http://www.econ.ucdavis.edu/faculty/gclark/Farewell%20to%20Alms/Clark%20-Surnames.pdf

Edwards, A.W.F. (2003). Human genetic diversity: Lewontin’s fallacy. BioEssays, 25, 798-801.

Frost, P. (2008). The 85% truism, Evo and Proud, January 4

Hawks, J., E.T. Wang, G.M. Cochran, H.C. Harpending, and R.K. Moyzis. (2007). Recent acceleration of human adaptive evolution, Proceedings of the National Academy of Sciences USA. 104, 20753-20758.

Jorde, L.B., W.S. Watkins, M.J. Bamshad, M.E. Dixon, C.E. Ricker, M.T. Seielstad, and M. A. Batzer. (2000). The Distribution of Human Genetic Diversity: A Comparison of Mitochondrial, Autosomal, and Y-Chromosome Data, American Journal of Human Genetics, 66, 979–988.

Klein, J., A. Sato, S. Nagl, and C. O’hUigin. (1998). Molecular trans-species polymorphism, Annual Review of Ecology and Systematics, 29, 1-21.

Lewontin, R. (1972). The apportionment of human diversity, Evolutionary Biology, 6, 381-398.

Long, J.C. and R.A. Kittles. (2003). Human Genetic Diversity and the Nonexistence of Biological Races, Human Biology, 81, 777-798.

Mitton, J.B. (1977). Genetic differentiation of races of man as judged by single-locus and multilocus analyses, American Naturalist, 111, 203-212.

Mitton, J.B. (1978). Measurement of differentiation: reply to Lewontin, Powell, and Taylor, American Naturalist, 112, 1142-1144.

Mountain, J.L. and N. Risch. (2004). Assessing genetic contributions to phenotypic differences among ‘racial’and ‘ethnic’groups, Nature Genetics, 36, S48 - S53.

Occidentalist (2011). Did Sarich Get It Right? Occidentalist, April 14
http://occidentalascent.wordpress.com/2011/04/14/did-sarich-get-it-right/

Sarich, V. and F. Miele. (2004). Race: The Reality of Human Differences, Basic Books.

Sesardic, N. (2010). Race: a social destruction of a biological concept, Biology and Philosophy, 25, 143-162.

Friday, April 15, 2011

Is teen motherhood pathological?

Figurine of African American grandmother and child.

Is teenage childbearing pathological? Anthropologist Linda Burton argues otherwise in her study of an African American community, and she cites other researchers who have come to similar conclusions:

Hamburg (1986) suggests that teenage childbearing, within certain poor black subgroups, reflects an alternative life-course strategy rather than a nonnormative life event. […] Furthermore, the long-term outcomes of teenage childbearing in these subcultures are not necessarily as devastating as mainstream impressions imply (Furstenberg et al. 1987). Rather, early childbearing may be perceived as a viable option that fosters individual growth, family continuity, and cultural survival in an environment in which few other avenues for enhancing development are available. (Burton, 1990, p. 124)

By viewing teenage childbearing as a reproductive strategy, with its own logic and life goals, we may better understand why it happens and know how to prevent it. Viewing it as a pathology has simply given us “solutions” that don’t work … and endless rationalizations for their failure to work.

Among African Americans, this reproductive strategy has one key characteristic: an accelerated family timetable. All life stages begin and end earlier:

Childhood: 1 to 10 years of age

Adolescence: 11 to 13

Motherhood: 14 to 26

Grandmotherhood: 35 to 45

Great grandmotherhood: 56 to 68

There is also separation of reproduction from marriage. Parenting is provided by the child’s mother and maternal grandmother. The father is usually absent. Households tend to be multigenerational with much exchange of services between younger and older generations and between siblings.

[…] given the fact that teenage childbearing families have more children per generation, it is likely that they have a broader array of potential caregivers, including older children who can assist in the care of their younger siblings, young adults who can help older family members, and young grandmothers who can parent the infants of teen mothers (Burton, 1990, p. 128)

Burton found that some African American women “covertly and sometimes overtly encouraged their teenage daughters to bear a child.” They wished to have the experience of rearing children—an experience denied them when they themselves had to rely on their maternal grandmothers many years earlier.

Once the maternal grandmother becomes a primary caregiver, the cycle of early motherhood tends to self-perpetuate. This is suggested by comments to Burton from a 35-year-old potential grandmother:

I suspect that my daughter (14 years old) will have a baby soon. If she doesn't I'll be too old to be a grandmother and to do the things I'm supposed to do, like raise my grandchild. (Burton, 1990, p. 132)

Similarly, a 58-year-old great-grandmother told Burton:

The best way to make sure that you have enough able bodies to take care of the needs in the family is to start the women having children as soon as they can. (Burton, 1990, p. 133)

Similarities and dissimilarities with the African marriage system

So far, most of the above sounds like the African system of mating and reproduction, as discussed in the last two posts. Unlike sub-Saharan Africa, however, polygyny is not institutionalized. Instead of being secondary sources of childcare, men are typically absent altogether:

In contrast to the duties of females, the role responsibilities of males in the family are ambiguous. Both the male and female respondents indicated that few familial duties are assigned to males. As young children, boys could assist girls with household tasks. Once male children reach later childhood, however, their energies are invested outside the home. Beginning at about age 10, the socialization of boys is primarily in the hands of peers and older men in the community who instruct them in the ways of survival in Gospel Hill. These instructions focus on job opportunities for black men, male/female relationships, and sexual behavior. (Burton, 1990, p. 135)

As in sub-Saharan Africa, the mother identifies first and foremost with her own kin. Unlike sub-Saharan Africa, however, she isn’t just less attached to the father. She is estranged from him, and this estrangement borders on hostility if the father consorts with white women. The following comment is from a 14-year-old mother:

Ever since I can remember I always expected to have a baby when I was 15 or 16 but I never believed I would ever have a chance to get a husband. One of the things my grandmother always said, "Pay your dues to your kin because they will take care of you. There ain't no reason to waste your time on a colored man because they don't want us no way." (Burton, 1990, p. 133)

Curiously, while citing Patricia Draper’s study on African marriage systems, Linda Burton attributes this polygyny and low paternal investment to factors that are specific to the United States. Hence, racism and the shift from manufacturing to services is said to prevent African American men from getting good jobs and becoming active fathers (Burton, 1990, p. 127).


Future of teenage childbearing among African Americans

While teenage childbearing can provide effective means of family formation, often more effective than later childbearing, it is not without its weaknesses. One of them is the willingness of maternal grandmothers to become primary caregivers. Personal autonomy is becoming a supreme value in all age groups of American society, including middle-aged and older women:

The majority of young grandmothers studied refused to assume the primary role in rearing their grandchildren. These grandmothers felt that being a surrogate parent for their grandchild did not fit with their current lifecourse activities--that included a variety of "young-adult" roles involving work, education, friendships, romance, and even their own continued childbearing. (Burton, 1990, p. 128)

Easier birth control, especially abortion, is also having an impact. Even when women wish to have children early in life, they still tend to postpone this kind of momentous decision—if given the choice.

African American fertility is now 2.2 children per woman, i.e., replacement level. And this rate is being buoyed up by a very fertile subculture of teen mothers. Most African Americans have, in fact, entered the zone of below-replacement fertility.


Conclusion

This teen mother subculture displays many elements of the African marriage system (polygyny, low paternal investment, high value placed on childbearing, strong ties with maternal kin). These elements, however, have to operate within Euro-American legal and cultural constraints, which are modeled on the marital norms of Eurasia in general and Western Europe in particular (long-term monogamy, high paternal investment, voluntary limitation of family size, relatively weak ties with kin beyond the nuclear family).

These constraints meet with varying degrees of compliance among African Americans. At one end of the continuum are those who fully comply. At the other are those who comply as little as possible, i.e., the teen mother subculture. The middle encompasses those who comply more or less.

Certain factions, notably the Black Muslims, have sought to create a new set of constraints that would be more in line with the African marriage system. But such efforts have largely failed. For the near future, at least, the teen mother subculture will become increasingly problematic, particularly as more and more older women refuse the obligations of grandmotherhood. The African American community as a whole will thus continue its slide into below-replacement fertility.


References

Burton, L.M. (1990). Teenage childbearing as an alternative life-course strategy in multigeneration black families, Human Nature, 1, 123-143.

Draper, P. (1989). African marriage systems: Perspectives from evolutionary ecology, Ethology and Sociobiology, 10, 145–169. http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1007&context=anthropologyfacpub

Friday, April 8, 2011

The African outlier


While birth rates fall everywhere else, sub-Saharan Africa remains an outlier of high fertility (2009).


Throughout most of the world, the demographic transition has played out as predicted. Fertility rates have fallen to replacement level and even lower, first in Europe and North America and more recently in East Asia, Southeast Asia, the Middle East and North Africa. The exceptions are societies where religious fundamentalists exert a strong influence on childbearing: Mormons and Amish in the United States, and Islamists in Saudi Arabia, Afghanistan, and Pakistan.

There is, however, an area where the demographic transition seems permanently stalled for reasons unrelated to religion. That area is sub-Saharan Africa. How come?

This puzzle caught the attention of anthropologist Patricia Draper back in the late 1980s. Sub-Saharan Africa had become an outlier of high fertility, even after adjustment for those factors that were lowering birth rates elsewhere. This excess fertility seemed to be due to a different social environment for mating and reproduction:

[…] in much of Africa, not only among country people but among urban populations as well, there persists high fertility and a pattern of parental investment in which both mothers and fathers invest, by Western standards, relatively little in each offspring and pursue a pattern of delegated parental responsibility (Draper and Harpending 1988). Coupled with low investment parenting is a mating pattern that permits early sexual activity, loose economic and emotional ties between spouses (Potash 1978), and in many cases the expectation on the part of both spouses that the marriage will end in divorce or separation, followed by the formation of another union (Aldous 1962; Lowy 1977; Oppong 1974; Mair 1953; Gibson 1958; Hunter 1961; Tuupainen 1970). Polygyny, still widespread in Africa, inhibits high male parental investment in children […] (Draper, 1989, p. 145-146)

In sub-Saharan Africa, parenting is assumed primarily by the mother and her kin. The parents, especially the father, are thus under much less pressure to limit family size. As Draper notes :

[…] people do not scale down expectations for large numbers of children precisely because their understandings about available resources take into account reservoirs of surrogate care among their kin. […] African men may see no urgency in reducing the numbers of their progeny precisely because a characteristically African set of socioecological circumstances permit many children to survive despite low father contribution to child support. (Draper, 1989, p. 147)

This is in contrast to the situation of parents elsewhere, particularly in modern urban settings, where a larger family perceptibly reduces the resources left over for the parents.

Will things change in the near future? Much depends on whether African families adopt the Eurasian marriage system, i.e., monogamy, long-lasting marital bonds, and high parental investment in children (including high paternal investment). To date, despite the efforts of missionaries and government authorities, there has been little change in this direction.

African men, in particular, are reluctant to assume a more active parental role:


Much of rural African subsistence is based on the work of women in their gardens; men make only modest contributions. Typically, rights in land are held by men by virtue of their membership in kinship or village units. A man who wishes to add another wife is under few constraints (provided his kinship group has the land and bridewealth), since women, in effect, pay their own way. They produce food, and they rear children. In rural areas, when a man marries an additional wife, he is awarded additional fields for this woman and her children (Bryson 1981). The importance of male labor to support such households is reduced. In former times, before colonially imposed peace, the male role in defense was important. But since central governments have been present, men who remain in rural villages spend their time in leisure, in management of household labor, or in local political affairs (Potash 1978). More recently, men absent themselves for long periods in migratory labor. They send remittances home that help to pay school and medical fees and to buy clothing. Nevertheless, the work of feeding people remains with women (Hafkin and Bay 1976; Vaughan 1983).


[…] Many efforts have been made to induce African men to increase their agricultural labor. The more successful of such ventures have followed the introduction of cash crops and the development of markets. Men are more willing to work at raising cash rather than traditional subsistence crops. However, since most cash crops are not food crops, women continue to do the subsistence farming, for which cash conversion is less possible, and they work even harder, since the men are busy with cash crops and have even less time for periodic help in the family gardens at clearing and harvest time (Obbo 1980; Whiting 1977; Kelley 1981). Characteristically, men do not return their earnings from cash crops to the household economy. This money is held separately and spent by men on their own projects (Vellenga 1983; Abu 1983; Bryson 1981). (Draper, 1989, p. 152)


As Africans migrate to other parts of the world, they tend to recreate the African marriage system in their host countries by using local people and institutions as “surrogate kin” Draper describes the situation in England, where young African couples often place their children in foster homes:

As might be expected, the outcome for all concerned does not work in the way it is expected to in West Africa. The foster parents interpret the infrequent visiting of their wards’ “real” parents as signs of parental neglect and become strongly attached to the foster children. This sometimes results in legal suits for transfer of custody to the foster parents (Ellis 1977). Meanwhile, the African parents make no comparable assumption that the delegation of care means they have surrendered formal rights in children. They consider that by having made safe and reliable arrangements for the care of children and by regular payment of fees, they are dispatching their immediate responsibility. (Draper, 1989, p. 164)

Ironically, when infertile Western couples go to Africa to adopt, as is increasingly the case, the adopted child evokes a degree of parental attachment that it would not normally evoke from its natural parents—even in the best of circumstances.


Reference

Draper, P. (1989). African marriage systems: Perspectives from evolutionary ecology, Ethology and Sociobiology, 10, 145–169.

http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1007&context=anthropologyfacpub

Friday, April 1, 2011

Are African women oppressed?


Guess who does the farmwork? In sub-Saharan Africa, women do most of the labor. On the other hand, they have more control over the fruits of their labor.


Are African women oppressed? For many, the answer is ‘yes’:

Much popular writing and many popular ideas about gender in Africa continue to rest on the belief that women in all societies in the entire world are oppressed and that African women are particularly oppressed. Even in scholarly studies, the assumption of universal male dominance of African social and economic relations persists. (Saidi, 2010, p. 12)

It’s true that women do most of the labor in sub-Saharan Africa. They are, in fact, largely self-reliant in providing for themselves and their children:

In sub-Saharan Africa, the labor of women was usually the work of daily subsistence. […] Hunting and warfare, usually the activities of men, could in contrast produce either a big windfall or nothing at all in terms of male production. […] Therefore, in a very simplistic way, it can be argued that female labor was the necessary labor—the labor from which surplus could be derived—whereas male labor could produce the luxury items, the status items. (Saidi, 2010, p. 15)

This argument ignores, however, the greater power of African women over the fruits of their labor. Often, this power was totally in the hands of women, typically older matriarchs:

The labor of young women, and young men, for that matter, in many East-Central African societies, particularly among the Sabi-speaking group of peoples, was historically controlled by the older female matrilineal kin of the young women, not by men at all. (Saidi, 2010, p. 16)

Indeed, one could argue that African men tended to occupy a peripheral role within the family:

Poewe found in her fieldwork that the marriage institution was highly flexible and discouraged strong, intense, or lasting solidarity between husband and wife. The male in these matrilineal societies did not produce for his progeny or for himself, but usually for a matriclan with whom he might or might not reside. His role, as husband, was to sexually satisfy and impregnate his wife and to take care of her during her pregnancies, but under no circumstances should a man be the object of “exclusive emotional investment or focus of attention. Instead, women are socialized to invest their emotions and material wealth in their respective matrilineages.” (Saidi, 2010, p. 16).

This situation has changed since the colonial era, largely under the impact of Christianity and Islam. Efforts have been made to restructure the African family, specifically to make the marriage bond monogamous, exclusive, and longer-lasting and to increase paternal investment in offspring.


Interestingly, there is evidence that this trend actually began some two centuries before the colonial era. Previously, the African family had been even more matrilineal, matrilocal, and matriarchal:


Murdock proves beyond reasonable doubt that the most ancient form of unilineal descent among the Niger-Congo, and therefore among the Bantu-speaking peoples (whose languages belong to the Niger-Congo family), was matriliny. He specifically reconstructs this feature for the proto-Bantu. He demonstrates it through his mapping of the scattered, relict preservation of matriliny all across the Niger-Congo-speaking regions, even in the Kordofanian branch of the Niger-Congo languages, which is spoken far away from the rest of the family in Sudan.


[…] The oral traditions of the Kanyok, who belong to the Central Savanna Bantu subgroup, still remember their shift from matrilineal to patrilineal descent a number of centuries ago, as John Yoder reveals. Most telling of all, the founders of the clans of the Gikuyu of Kenya are female, even though today the Gikuyu are strongly patrilineal. By definition, matrilineal clans must have female founders; therefore, this is undisputed evidence for prior matriliny among the Bantu-speaking peoples of the eastern Kenya highlands.


[…] The historical priority of matriliny among the Niger-Congo peoples in general—as well as among peoples speaking languages of the Bantu subgroup of Niger-Congo—is extensively and convincingly demonstrated by the comparative ethnographic evidence. Recent work in linguistic reconstruction directly supports the view that the early Bantu communities, who established themselves successively more widely in the rainforest and then in the southern savannas and eastern Africa during the last three thousand years BCE, observed unilineal descent in the form of matrilineages and/or matriclans. (Saidi, 2010, pp. 13-14)


According to Saidi (2010, pp. 12-19), sub-Saharan Africa saw a relative shift of power from women to men from around 1500 onward—apparently as a result of warfare induced by the slave trade. On the one hand, war enhanced the prestige of men through the plundered wealth they brought to their communities. On the other, women looked to men for protection during times of war.


Was there previously, then, a golden age of non-oppression? And are African women now oppressed? In truth, words like ‘oppression’ are easily abused in a context where the goal of life is not self-maximization. Yes, African women produce far beyond their own needs, but the economic surplus goes primarily to their children. If anyone is getting something for nothing, it is surely the children.


But that’s not how Africans themselves see it—or for that matter humans in any traditional society. Children are literally seen as the ‘after-life.’ It’s not out of masochism that African mothers make sacrifices for them. It’s out of a profound belief that “no one gets out of here alive”—other than one’s children and their descendents.


Reference


Saidi, C. (2010). Women’s Authority and Society in Early East-Central Africa, University of Rochester Press.