Sperm Count Biovariation: An Introduction and Primer
Is the panic over sperm counts warranted? It could be normal for sperm counts to vary.
Authors: Meredith Reiches, Marion Boulicault and Sarah S. Richardson
Blog Series Editor: Annika Gompers
Image Credit: PixaBay, Graphic-mama team, PixaBay license
For at least half a century, scientists have been worrying about sperm. Are men making enough genetically healthy, robust swimmers to perpetuate the species? Should we be concerned about the future of humanity?
The worry began (at least in print) in a 1974 paper in the journal Fertility and Sterility, in which scientists Nelson and Bunge reported an alarming result: “something has altered the fertile male population to depress the semen analysis remarkably.” In 2017, these worries culminated in a high-impact meta-analysis (a study combining samples from multiple other studies) reporting that average sperm counts among “Western” populations have decreased by 50% since the 1970s. The authors, Hagai Levine, Shanna Swan, and colleagues, claim that there is no end in sight to the decline. While earlier studies of sperm counts met skepticism from other scientists, the meta-analysis has been greeted with broad endorsements by researchers across a range of fields.
The public outreach arm of the sperm count alarm system is active and far-reaching. Swan recently released Count Down, a book for general audiences that situates the 2017 study’s findings in an apocalyptic narrative of pollutant-driven extinction. “Some of what we’ve been thinking of as fiction from stories such as The Handmaid’s Tale and Children of Men,” Swan writes, “is rapidly becoming a reality.” She likens the state of current sperm decline research to “where global warming was forty years ago—reported upon but denied or ignored... Increasingly, scientists are in agreement on the threat; now, we need the public to take this issue seriously.” Renowned environmental activist Erin Brockovich took up Swan’s message in a recent Guardian opinion piece: “That would mean no babies. No reproduction. No more humans. Forgive me for asking: why isn’t the UN calling an emergency meeting on this right now?”
Both the extraordinary biological claims of the meta-analysis of sperm count trends and the public attention it continues to garner raised questions for the GenderSci Lab, which specializes in analyzing bias and hype in the sciences of sex, gender, and reproduction and in the intersectional study of race, gender, and science. Were the data sufficient to argue that a decline had taken place, and were predictions of imminent disaster warranted? What consequences might popular uptake of these claims have for the well-being and freedom of people of all sexes and genders?
Our new paper: The argument
We set out to reanalyze the 2017 study. We wanted to understand whether sperm counts were truly declining and whether evidence supported the authors' claims of imminent danger to fertility, health, and the environment. That analysis led us to be skeptical of claims of dramatic global sperm decline leading to an imminent crisis in male fertility and health. We think the patterns hinted at in Levine et al.’s meta-analysis rather offer compelling evidence that sperm count can vary both pathologically and non-pathologically under different conditions and environments. We call this view, developed in our new article just out in the journal Human Fertility, the “Sperm Count Biovariability” hypothesis. In contrast, we dub Levine and Swan’s framework the “Sperm Count Decline” hypothesis.
Our new article uncovers and systematically questions a set of shared assumptions with which sperm researchers, including Levine and colleagues, approach historical sperm count data: (1) that a decline in sperm counts from 1970s levels necessarily indicates a decline in male fertility and health, and is a sign of a degrading environment; (2) that nations can serve as appropriate proxies for stable populations or biologically meaningful environments; and that (3) “Western” vs “Other” are appropriate categories for data aggregation, analysis and comparison. Together, these assumptions make up what we call the “Sperm Count Decline” (SCD) hypothesis.
In contrast to the SCD, the Sperm Count Biovariability (SCB) hypothesis begins with the premise that “above the threshold necessary for fertility, there is no basis to assume that high average population sperm counts are optimal.” Nor are there good reasons to assume that ‘Western’ sperm counts in the 1970s constitute a species-typical baseline. As such, SCD and SCB (summarized below in the table) “represent two interpretive frameworks for the same data” that allow for different conclusions to be drawn. Freed from the framing of impending doom that attaches to the Sperm Count Decline hypothesis, the Sperm Count Biovariability hypothesis opens wider possibilities for interpreting sperm count trends in human populations.
Two hypotheses for interpreting trends in human sperm count.
(Source: Boulicault, et al. 2021)
Why it Matters: The Sperm Count Decline hypothesis is a new manifestation of a familiarly pernicious theme
Sperm decline claims invoke powerful rhetorics and narratives around gender, sex, race, ethnicity, and anxieties about our future. Of particular concern is the uptake of this work by overtly white supremacist and misogynistic groups. These groups have used Levine and Swan’s research to argue that the fertility and health of men in whiter “Western” nations are in imminent danger, often linking the danger to the perceived increase in ethnic and racial diversity and to the influence of feminist and anti-racist social movements.
“What these anxieties have in common with the threat of sperm count decline is the premise that, in an environmentally clean and appropriately-gendered social past, there existed an optimal and natural manifestation of masculinity”
To be sure, scientists can’t fully control how their research is interpreted once it appears in public. Levine and Swan are writing within a culture and history that is already imbued with racist and sexist ideologies. But the historically integral role of biological science in reflecting and reinforcing harmful social and political biases is uncontroversial and richly studied, and must be taken into account by reproductive scientists. The GenderSci Lab’s engagement with the sperm decline hypothesis calls on Levine, Swan and other reproductive health scientists to work ethically and reflectively with awareness of this harmful tradition. In proposing the SCB, we hope to elevate a discussion around the importance of surrounding science with critical social perspectives and of engaging these perspectives in research design itself.
The idea that men--particularly white men--are in decline has a long history within biomedicine. Anxious scientists and publics have long examined the male body and psyche for symptoms of degeneration. Fears of emasculation have attached to reports that the Y-chromosome is losing genetic material, that men’s testosterone levels are on the fritz, and to assertions that male fetuses are more vulnerable in utero, among others. There are also less body-specific fears, such as the claim that men’s attitudes and behaviors are becoming feminized by the technologies, mores, and diets of modern life. What these anxieties have in common with the threat of sperm count decline is the premise that, in an environmentally clean and appropriately-gendered social past, there existed an optimal and natural manifestation of masculinity. Under these conditions, men’s bodies and minds allowed them to fulfill their proper gender roles, achieving and maintaining power.
Lined up in the rogue’s gallery alongside related theories, the Sperm Count Decline hypothesis looks familiar. It probes a biological marker for signs of imminent threat to men’s essential maleness and thus for societies--and species--that rely on that maleness. In identifying causes, it points a finger at modernity in the form of environmental pollutants and an array of lifestyle factors, from diet to sedentism to experiences of subordination. Simultaneously, it gestures over its shoulder toward a time and place when life was better--and as it ought to be--for men.
Well, better for certain men, that is. Another characteristic that the Sperm Count Decline hypothesis shares with related narratives of male degeneration is its concern for “Western” men. In the context of the study, and in many other places, “Western” functions as a code word for “white.” Levine and colleagues found that the sperm counts of men in parts of the world designated “non-Western” remain lower than the 1970s “Western” averages for the duration of the study period. Like other research focused on maleness, the recent meta-analysis does not flag environmental exposures and other risks of modernity as causes for concern about the well-being and reproductive capabilities of men in the “non-Western” world.
The Sperm Count Biovariability hypothesis calls for rigor and ethical reflection in men’s health research
Image Credit: PixaBay, geralt, PixaBay license
We are grateful to Dr. Hagai Levine, who generously shared with us the data his research team painstakingly collected to conduct their meta-analysis. We are also grateful to the andrologists who granted us interviews. Their expert assessments of Levine and Swan’s study helped us to grasp its standing in the field, to better understand research methods and paradigms within andrology, and to shape our contribution so that it could enter the conversation about sperm count decline among andrologists.
By proposing an alternative approach to sperm count data, we aim to contribute to the burgeoning discussion among reproductive health scientists and other researchers and clinicians about men’s health. We offer the SCB as a framework in service of research on men’s reproductive health and well-being. In fact, we believe that the forms of analysis and methodological approaches we advocate will not only support research on men’s health, but will lead to improved research design and interpretive strategies around the reproductive health and bodies of people of all genders.
We start from a premise that allows us to ask questions that are not possible when working from the assumption that danger is imminent and that our gendered boundaries and well-being are in decline. The SCB allows for the possibility that people who produce sperm may do so at different levels across space and time, within and between individuals, and much of that variation may be non-pathological. As a result, we are able to approach questions about the developmental, cross-sectional, and health contexts of sperm production with curiosity about and concern for the well-being of all people who produce sperm, across geographic categories and racial and ethnic lines.
The Sperm Count Biovariability hypothesis, in the best tradition of feminist science studies scholarship, goes beyond critique; it opens opportunities for generating new knowledge. Inspired by recent models like the reformulation of evolutionary theories of same sex sexual behavior articulated by Monk and colleagues, the Sperm Count Biovariability hypothesis aims to generate conversation within and beyond the reproductive health sciences and to produce hypotheses and knowledge that matter for people’s lives.
Critical work that results in novel hypotheses, data practices, analyses, interpretations, and disseminations of findings is a profoundly interdisciplinary undertaking. It requires a commitment to engaging simultaneously with the biomaterial realities, situated histories, and contemporary politics of research questions--in this case, about human fertility. In dialogue with andrologists, the interdisciplinary GenderSci Lab authorship team, made up of philosophers, historians of science, public health epidemiologists, organismic biologists, and anthropologists, has generated a powerful alternative to mainstream accounts of sperm decline.
Read on to learn more:
This primer begins a multi-part blog series explaining and contextualizing the contribution of our new paper in the journal Human Fertility for a wide interdisciplinary audience.
What are we counting when we count sperm?
We begin the series with a whirlwind tour through the world of sperm metrics. In “What does sperm count count?,” Marion Boulicault asks: How are sperm count and sperm concentration measured? What are the challenges to counting sperm? How has sperm counting changed across time? And what are the implications of all of this for research on global sperm count decline? She shows that, while there may be limitations to the use of sperm count as a measure of fertility, “what sperm count does predictably measure, at least in certain socio-cultural contexts and time periods, is social anxieties about threatened masculinity.”
The many problems with sperm count decline researchers’ “West”/“Other” distinction
Our next blog post explores the troubling assumptions of Levine et al.’s picture of global sperm count variation, epitomized by the classification of global sperm counts into just two bins, “West” and “Other.” In “Around the world in pursuit of (vanishing) sperm,” Jonathan Galka takes us on a journey through the geographic categories that underlie Levine et al’s research. Using vivid examples based on close analysis of local contextual details, he demonstrates the severe limitations of Levine et al’s unquestioned choice to divide the study into West vs Other. As he puts it: “‘West’ and ‘other’ are not tenable categories, and an analysis of their boundaries from multiple angles sees their geographic and demographic architectures crumble.”
What’s in a number?
Next, we shift from places to statistics. As Alex Borsa shows, the story of sperm count decline is a statistical one. Research takes sperm count metrics from individuals from across the world and transforms these into an account of temporal changes across statistical populations. In this blog post, Borsa shows us how this is done, deconstructing the assumptions behind some of Levine et al.’s key statistical moves.
The Alt-right and the Sperm Decline Hypothesis
Our final two blog posts examine the uptake and interpretation of sperm decline in right wing communities. In her piece, Meg Perret takes the reader deep into online forums where members of the alt-right debate the causes of sperm count decline following the publication of Levine et al. (2017). These alt-right online forums say that the rise of feminism, increase in environmental pollution, and human overpopulation especially among human minorities could be causing the decline of sperm count in “Western” countries.
A Q&A with Alexandra Minna Stern
We conclude with a conversation with Alexandra Minna Stern, author of the 2019 book Proud Boys and the White Ethnostate. Stern, a leading historian of the eugenics era, helps us understand the particular appeal of scientific theories of male reproductive decline to present-day alt-right movements. Stern also offers guidance for scientists and scholars of all disciplines working to anticipate, engage, and counter attempts by the alt-right to invoke scientific authority to bolster their racist and sexist beliefs.
Media contact:
For media and other inquiries, contact us at genderscilab@gmail.com
Recommended Citation
Reiches, Meredith, Marion Boulicault and Sarah S. Richardson, “Sperm Count Biovariation: An Introduction and Primer.” GenderSci Blog, 2021 May 4, genderscilab.org/blog/sperm-count-biovariation-an-introduction-and-primer
Statement of Intellectual Labor
Sarah Richardson and Marion Boulicault conceptualized the blog post. Meredith Reiches led the writing process, and Marion Boulicault and Sarah Richardson contributed writing and editing.