In Tune with Natural Selection

Prithvi Chandavarkar

             The inspiration for this investigative piece comes from years of hearing phrases like, ‘My sister and I can’t make it, it’s our time of month.’, ‘Can we please go for a drink? I can’t handle being in proximity with my wife and daughters right now!’ and a very surprising reminder (I know a lot of older people than myself, in case you were wondering) that’s coming right up. While this statement has, among others, nestled its way comfortably into the crevices of my mind over the years, sitting in a microbiology classroom today, I witnessed my professor use the example of synchronizing menstrual cycles to prove how interesting studying one’s body make-up (pun intended) can be. Something tells me that I’m not the only one who’s heard statements like these in their life and while I certainly might not have first-hand experience, I tend to trust the word of the women in my life, and rest assured there are and have been more than enough.
It was completely random, keeping in tune with the chance based ideas at work here, with which this piece even came to be written at all. The findings however, will prove, amusingly, are not so. There have actually been a number of surveys, studies and academic work done on the subject, and I warn you in advance that I will not be advocating my view with any vehemence and will be acknowledging contradictory data and will attempt to prove that what may seem to be an opposing idea, might not really be the case.
Let’s sum up the objective of this work before heading any further, and in modest words it is that, ‘The synchronizing of the menstrual cycles of women who live together/spend a lot of time together is an expression of Natural Selection.’
An elementary knowledge of the woman’s reproductive system is required to be able to grapple with what I’m about to extrapolate on in the paragraphs to come. Bearing in mind that scientific writing isn’t for everyone, I’ll try to keep terms and concepts as simple as possible, and explain them as and when I feel it would be required. So then, what is Natural Selection, really? A fair number of us seem to have by an arbitrary understanding of the term and other related ones like evolution, genes and so on. Quite simply, Webster says that “Natural Selection” is a natural process that results in the survival and reproductive success of individuals or groups best adjusted to their environment and that leads to the perpetuation of genetic qualities best suited to that particular environment.
While on the topic of explanations, allow me to quickly sum up the average menstrual cycle before we proceed any further. A woman’s menstrual cycle takes an average of 28 days to complete and her body goes through a smattering and convoluted bunch of changes during this time, most of which, we are not really concerned about here. However, what we need to understand are the ovulating stage or the ‘middle’ of the cycle as well as the menses stage, which is considered to be the ‘end’ of a current cycle.
Brownie points if you know what pheromones are, but just in case you don’t, let me hit you with the facts. Webster says here again that a “pheromone” is a chemical substance that an animal or insect produces in order to attract other animals or insects and especially a mate. For comic and dramatic effect, as well as to help you relate a little better, I would prefer to use a couple of examples for a pheromone from Urban Dictionary. ‘Her pheromones were a huge influence on me being sexually aroused’, the notoriously smartass website declares along with the slightly more blunt, ‘We had coitus on the first date because of our pheromones.’ So in short, pheromones make you attractive to another human being, taking multiple sexualities into account. Pheromones, along with intellect, looks, diction, pitch, other tell-tale signs of body language, smell, and touch, go a long way in what I like to call, ‘The Science of Attraction.’ But that is a different matter deserving its own literature.
Back to today’s class,  if I remember correctly, the professor asked all the young women in class if they’ve ever noticed the phenomena of synching cycles. When I saw the expressions on the faces of virtually every female in class change, I had a light switch on in the back of my own ever active cranium. What’s been a day of avid and focused investigation led me to some interesting AF findings, which I’m about to share with you in the paragraphs below; which brings us back to the crux of the matter. It turns out that you and me aren’t the first and likely won’t be the last in this seemingly overlooked observance of everyday life. By the end of this piece, I hope that said observance, albeit yours or someone else’s, transforms into an understanding of sorts. And remember, an understanding is always open to alternate understandings, if they’re backed up by more than a polemic and uninformed opinions, that is. To borrow a few lines from a 2015 HuffPost article, “Menstrual synchrony is a theory that women who live in close proximity to one another tend to experience their periods around the same time.”Pheromones, as I’ve touched upon above, have been thought to play a role in this phenomena.
The concept was first documented in Martha McClintock’s seminal research paper titled ‘Menstrual Synchrony and Suppression’ in 1971. I’ll keep things simple and leave the differentiation and calculus aside and sum up the findings in a simple manner, instead.
McClintock observed 135 female Wellesley College students living in the same dorm and found “a significant increase in synchronization of onset dates” among the women who spent a lot of time together. According to these findings, it’s not just an anecdotal phenomenon — women do in fact, sync up. McClintock’s paper has gone a long way to prove that synchronizing cycles do in fact, exist. All criticism aside, that’s part one of my little ‘theory’ proved.
Before going on to part two, i.e. that menstrual synchronicity is an expression of Natural Selection, let’s look at the data that contests McClintock’s paper.
The chief criticism here comes from the fiery pens (or burnt keyboard) of Zhengwei Yang and Jeffrey C, who once taking into account the irregularity of a menstrual cycle (they’re not always exactly 28 days, like the month of February), they found that an apparent synchronizing is simply a depiction of what they termed ‘chance’. And I’m beyond glad they did. Forgive the linguistic twist, but isn’t chance the penultimate factor in the evolutionary processes of Natural Selection and Random Selection? In this light, it is the twin ‘chances’ at work here; namely the chance of cycles synching with the chance of propagating the species, that in fact bolsters my case.
Another criticism thrown at McClintock’s findings is that due to the irregularities, some periods align with one another briefly only to diverge in their timeliness over time. And again, I’m ecstatic that this is the case. This apparent shifting of cycles to a parallel collective happening, to ones that are different in time and scale, again goes to prove that if and when the cycles do line up, they drastically increase the likelihood of reproduction taking place, ceteris paribus. Furthermore, since the likelihood that the women who are in proximity with one another would have access to similar qualities and quantities of nutrition, similar sleep cycles and lifestyles due to economic backgrounds, is quite high. It is obvious that the synchronizing of their cycles, even if not a constant thing, are likely to be more concurrent on average, as opposed to being divergent. That being said, we may now move on to what I feel is the most interesting part of this academic essay, that being the relation of the proposed synchronicity to that of the propagation of the species. Imagine that! A group of ‘cranky’ women and girls are actually a manifestation of nature’s will to help the species increase! While this might sound utterly preposterous at first glance, is it, really..?
Now that I have your attention, here we are, the piece de la resistance as I like to tragic-comically call it, let’s begin. Remember back to when you or someone you know was little? If you have a little one in your world right now, all the better. If you’re looking for something specific to notice, look for the child’s sweet tooth. Is the creature able to curtail its wanton desire for sugar for an entire month? Can it abate it for a week? Or how about a day? Endowed with a glucose craving and utilizing metabolism like that of the average baby, could you? Let’s relate that analogy to a diametrically parallel phenomenon we’ve seem to have forgotten for a little while now. That neglected little nugget is Natural Selection. In the same way that the collective need of the cells and tissues in our bodies crave glucose in un-stoppered frenzies, so does the manifest need to propagate the species, collectively, in the form of the most natural instinct in known to homo-sapiens; the sex instinct. All in all we crave sweet. Just this time, it’s not really that simple.
Now let’s relate this to something a little err… closer to home. When a man ejaculates, the number of viable sperm far outreach what is required (a single one, in the end) for fertilization to occur. In the same way, the fact that women release 1 to 2 eggs a month on ovulation, is more than made up for by the synchronizing of cycles in favour of fertilization.
If that wasn’t clear enough, let’s put hopelessly convoluted theorists whom I admire (Judith Butler, Richard Dawkins et al) to shame and run through this in an even more relatable way. Babies want sugar, and so do adults. It’s just that adults are more prone to adapt their sexual proclivities and receptiveness in a way that babies cannot, because babies are, well, babies.
It is in the manifestation of two (possibly co-incidental) complimentary and incidental expressions Natural Selection at work that results in the synchronization we’ve been dealing with. It can be said (just not to most Indian parents, hostel wardens et al) that the synchronizing of a woman’s menstruation cycle, from a heterosexual perspective, is the expression of a logically and elementary level mathematically provable Natural Selection. And a male’s ‘chase’ of her, is the same. Here however, as in a variety of matters concerning women, men are not more than passively important.
Let us not naturally forget that pheromones have a huge role to play right.. about.. Now. A woman exudes her pheromones or ‘love scents’ as I probably shouldn’t call them, into the air when she is midway through her cycle (remember ovulation?) as her ovaries have released eggs to be hopefully fertilized by sperm and she won’t have to endure that wretched backache again this month (studies from 2015 have shown that the pain has been incidentally linked to an increased likelihood of conception in the near future). Let me not do the math for you, but let you do it yourself. And as I mentioned before, logic is fine too.
Picture the entire female population of say, a hostel, ovulating at the same time. The sheer amount of pheromones in the air is enough to attract males of all shapes, intellects, smells and hairlines. Unconsciously all pulled all at once. Now break this image in your mind’s eye and paint a new one: women whose cycles are on a different time scale. Assuming none of them are on birth control, not only is this statistically unlikely but it also means that the likelihood of attracting varying types of new genes to propagate with those of the different women is greatly reduced due to this apparently ‘widespread’ and therefore ‘not gluttonous’ demand for ‘sugar’, and this most evidently positions the male genes in predicaments which might not favour them being around as and when the women’s pheromones are in the atmosphere at their apparent leisure.
It makes sense that the coinciding of menstrual cycles of women in a social group over a period of time is a positively proportional expression of Natural Selection in spite of the relatively unexceptionally quantified data, then. The quality of it however, is thankfully a completely different matter. Another indicator I didn’t mention up until now, is that the synchronizing of cycles tends to fall in tune with that of the ‘alpha’ female (as McClintock’s piece suggests). The alpha woman is the woman who has the most favorable genes in a population and provides the single largest clue in favour of this investigation simply by being the most likely to be sought after by a variety of genes. Her choices of partner for sexual relations determines if healthy gene combinations will propagate, therefore she is likely to co-produce the most healthy offspring (social and personal circumstances notwithstanding).
While it can be said that in conservative societies that the healthy propagation of genes is hampered with the presence of social barriers, which in turn leads to a dwindling in gene variety and prevents the mixing of new genes into the population, it can also be said that these barriers actually make Natural Selection try even harder to propagate it’s ‘divine will’. Just ask the neighborhood Peeping Tom.