Being Human: The anthropology of menstruation

Vlada’s bio: I am a first year anthropology student, originally from Ukraine. After I finished a Fine Arts degree I decided to look to science and once I discovered anthropology it immediately grabbed my attention. Both social and biological anthropology interested me, however it was evolutionary anthropology that ignited my thirst for knowledge.

Taboo is a system of placing prohibitions on certain actions and utterances in a society (Agyekum, 2002). Taboo is universal and exists in every society, with varying degrees of importance in the cultural context. Menstruation can be defined in biological terms as a “shedding of the superficial lining” of the uterus, and the correlating reduction in progesterone (Jarrell, 2018). Menstruation also has a culturally dependent definition and is often a taboo topic in most social contexts. The current Western attitudes influenced partially by the feminist ideologies, partially by the modern tendency of demystification and rationalization of most biological and ‘natural’ processes, has somewhat alleviated the taboos surrounding menstruation, but has not eradicated them. Despite the recent attempts to destigmatize menstruation and broader body positivity trends, women still reportedly experience shame about their menstruation, shame that spills to the whole of their reproductive organs inclusively (Schooler et al., 2005). Menstruation is inevitably linked to sex and reproduction, it is often interpreted in conjunction with fertility or infertility, purity and uncleanliness or spiritual and emotional stability or instability. The evolution of human menstruation is poorly understood. When compared to our closest primate relatives, human females exhibit a much more prominent menstruation and virtually no estrus – a period of fertility and heightened sexual behaviour. The rhythm and synchronized nature of our menstruation could be linked to our social evolution, where such a well ‘known’ and yet poorly described phenomena as synchronized cycles could have evolved as a way to maintain good group dynamics and protection amongst females and maximized parental support from the males. With such inconclusive evolutionary data and so much social and cultural weight given to interpretations of menstruation, I will argue that menstruation is best understood as a social phenomenon.

Human females’ reproductive system, and especially menstruation, is amongst the most unique in the primate family. There are many theories as to why menstruation evolved at all, since it is not a common occurrence in the animal kingdom. Theories range from sperm-born pathogen removal, through energy conservation and to uterine preconditioning (Emera, Romero and Wagner, 2012). To fully appreciate the difference of our menstruation we need to first discuss the other close members of our family. The mating systems of non-arboreal primates can be placed on a spectrum between two models: a ‘one-male’ harem system or a ‘multi-male’ system (Knight, 1991; Dunbar, 1988). The former system stipulates that a dominant male controls a harem of passive females and protects them from the other males. In this model, females tend to compete for the dominant male’s attention, this, in turn, may lead to shorter estrus periods – a fertile time for a female that is usually characterized by some form of signalling like breast glands swelling and expulsion of a specific odour (Burley, 1979). If each female is only fertile for a short period of time, and it is explicitly evident to the male, the inter-female competition decreases. However, a single male can only manage a small amount of females. In case where the harem grows too large or the females are more often in heat, the ‘multi-male’ system works better. Since in this model there is no shortage of males, females face less pressure to limit the sexual intercourse to exclusively fertile days and it becomes less necessary that their ovulation appears in sequence as to not overlap (Knight, 1991). In many non-primate species, females have evolved to restrict sexual activity to exclusively fertile periods, their hormones that are responsible for fertility are also in charge of restricting sexual behavior (Wallen and Zehn, 2004). In contrast, many primates, including humans, are not controlled sexually by their hormones and are some of few species that participate in intercourse without a necessarily reproductive goal.

Unlike other primates, however, human females do not possess an estrus period and instead have the most pronounced menstruation. Women also lose the largest amount of blood during that period amongst any female primate (Knight, 1991). This loss is detrimental and requires an increase in food intake to replenish it. Furthermore, concealed ovulation not only creates decreased parental certainty in males who cannot be sure at which exact point the female is able to conceive, but also increases unwanted pregnancies for women who cannot accurately control this process since they are also unaware (Burley, 1979). What follows is that human female has no way of signalling readiness for reproduction but instead has a very strong and clear signal as to when sex is not reproductively viable in the form of the menstruation. Hence, while non-human primates generally signal ‘no’ and periodically present a ‘yes’, humans generally present a ‘yes’ signal with a periodic ‘no’ (Knight, 1991)., unfortunately, the biological advantages of this evolutionary route are poorly understood and remain a question to be answered.

Many mammals experience seasonality in their reproductive cycles (Dunbar, 1988). It is often dependent on the amounts of light and temperatures. If a given season is a better time to give birth, because food is abundant or the temperature is more forgiving, then the synchronization of the environment and the fertility cycles appear more prominently. Primates are less dependent on seasons, and humans even less so, although there are still some consistent spikes in births during summer. But synchrony doesn’t only exist in the fertility cycles, but also in the menstruation cycles. It is rare in the primate kingdom as it requires a few uninterrupted cycles of menstruation which doesn’t often happen in the normal conditions (Knight, 1991). In humans ,this phenomena has been studied since 1970s. Many theories and studies have been conducted which proved the existence of synchronization but not the cause. One of the theories on evolution of synchronization in females comes from Paul Turke. Turke believed that ‘proto-humans’ lived in chimpanzee like units with promiscuous multi-male system (Knight, 1991). However, as the environment began to change and the groups became larger, the females had to organize themselves in some sort of units or coalitions to elicit protection from males and support from the group in rearing and provision for the offspring. Thus, Turke argues, that females had extended their estrus signals to overlap with other females to the point of complete erasure of distinction as well as eventually synchronized with their local groups to get as much male support as possible. Unfortunately, Turke’s hypothesis does not rest on any paleontological evidence, nor any research done with hunter-gatherers and thus remain unsubstantiated (Knight, 1991).

So, if our understanding of menstruation as an evolutionary driven phenomena is not particularly clear, we should approach it from a social perspective. In many cultures menstruation is often awarded negative connotations (Gomez-Sanchez et al., 2012). It is talked of (or actively avoided talking about) generally as a taboo. There are a variety of social attitudes towards menstruation some of which are: ‘uncleanliness’ and pollution, religious or mystical evil, and social shame and isolation. Cross-culturally, the concept of ‘impurity’ is often associated to menstruation. The Bible refers to the impurity of menstruating women, which some Christian institutions interpreted as a prohibitive rule to their admission to church during those times (Gomez-Sanchez et al., 2012; Dammery, 2016). In Leviticus the woman ‘afflicted’ was dictated to be separated from her husband for seven days, her ‘polluting’ blood was not to touch a man and no sexual intercourse could be allowed at that time (Worton and Wilson, 2004). The Koran also describes menstruation as evil and impure, thus relating it to a disease (Gomez-Sanchez et al., 2012).  In Nepal, women are socially ostracized during menstruation as they are considered impure (Thapa and Aro, 2021). In rural areas, they are made to live in sheds called chhaupadi during that time, which poses health and wellbeing risks. Thapa and Aro’s study (2021) also found that attempts to change the social attitude towards menstruation in those areas have been unsuccessful so far and have received considerable resistance from the traditionally-oriented population.

In ancient Greek and Roman culture, an idea of a woman as an ‘unfinished man’ appeared (Worton and Wilson, 2004). It described women’s period blood as a waste product; men, according to this theory, are warmer and burn off any excess blood, while women are cooler and are unable to do so, hence they are incomplete and weaker than men. Later, in Protestant England, menstrual blood was considered so ‘evil’ that it could corrode a man’s penis and cause disease. It was often described as the culprit in the creation of syphilis and measles (Worton and Wilson, 2004). Similar beliefs were spread around Medieval Europe, it was said that it can keep grains from germinating, rust the iron, spoil the food and wither the plants (Gomez-Sanchez et al., 2012).

However, it is not all negative. Worton and Wilson (2004) explore early modern English and other examples of interpretations of menstrual blood not as polluting, dangerous and disastrous but as nourishing, healthy and pure. They discuss writings of opposing views such as of Thomas Raynold and Reginald Scot, who ridiculed the assertions and lies surrounding menstruation and its attribution to witchcraft, as well as John Sadler, who argued that menstrual blood can only be pure and incorrupt as it is used for “preservation of mankind”. In other parts of the world, menstrual blood would sometimes be attributed healing and magical properties. In the south of Russia, it was believed that it could be used to produce love potions, or heal a plethora of diseases (Gomez-Sanchez et al., 2012).

In essence, menstruation could be described as a phenomenon that developed under close biological/social ties. Given that the evolution of menstruation and the menstrual cycle are closely related to inter-female and social group dynamics, as well as the mass of cultural meanings that completely alter not only psychological perceptions but also physical experiences behind menstruation, I believe it is best understood as a social phenomenon. The cultural evidence is mounting with every ethnographic study done on this topic, suggesting an even deeper connection of culture to our understanding and experience of menstruation. Menstruation is often a taboo topic, a process better left concealed, shamed and avoided. It is a reason for many cultures to ostracize and punish women, a process that is often difficult to uproot. It is often associated with disease, impurity, imperfection and even evil. Nevertheless, menstruation is also a powerful object of magic. Menstrual blood is often associated with healing properties, growing and nourishment as well as purity.  A menstruating woman is in a state of ambiguity, neither wounded nor healthy, both promoting fertility and life and spreading disease and disgust. Thus, she is both inferior and superior, a fearful combination indeed. This ambiguous state is one of the main reasons, I believe, even now we still use blue liquid in the tampon commercials and lower our voices in front of the male colleagues when discussing ‘those days’.

 

References

Agyekum, K. (2002). Menstruation as a Verbal Taboo among the Akan of Ghana. Journal of Anthropological Research, 58(3), pp. 367–387.

Burley, N. (1979) The Evolution of Concealed Ovulation. The American Naturalist, 114(6), pp. 835 – 858.

Dammery, S. (2016) First Blood: A Cultural Study of Menarche. Cayton, Australia: Monash University Publishing.

Dunbar, R. I. M. (1988) Primate social systems. London: Croom Helm

Emera, D., Romero, R. and Wagner, G. (2012) The Evolution of Menstruation: A New Model for Genetic Assimilation, BioEssays : news and reviews in molecular, cellular and developmental biology, 34(1), pp. 26–35.

Jarrell, J., (2018) The Significance and Evolution of Menstruation, Best practice & research. Clinical obstetrics & gynaecology, 50, pp. 18–26.

Gomez-Sanchez P.I et al. (2012) Menstruation in History, Investigacion y Educacion en Enfermeria, 30(3), pp. 371–377.

Knight, C. (1991) Blood relations: menstruation and the origins of culture. New Haven: Yale University Press.

Schooler, D., Ward, L. M., Merriwether, A., and Caruthers, A. S. (2005) Cycles of Shame: Menstrual Shame, Body Shame, and Sexual Decision-Making. The Journal of Sex Research, 42(4), pp. 324–334.

Thapa, S., Aro, A.R. (2021) Menstruation means impurity: multilevel interventions are needed to break the menstrual taboo in Nepal. BMC Women’s Health, 21(84).

Wallen, K., Zehr, J. L. (2004) Hormones and History: The Evolution and Development of Primate Female Sexuality. The Journal of Sex Research, 41(1), pp. 101–112.

Worton, M, and Wilson, T. W. (2004) National Healths : Gender, Sexuality and Health in a Cross-Cultural Context, London: Taylor & Francis Group.