More voices are always better: Tackling power differentials in knowledge production and access in human biology

Conducting Human Biology Research Using Invasive Clinical Samples: Methods, Strengths, and Limitations

Invasive biological samples collected during clinical care represent a valuable yet underutilized source of information about human biology. However, the challenges of working with clinical personnel and the invasive nature of sample collection in biomedical studies can hinder the acquisition of sufficiently large sample sizes for robust statistical analyses. In addition, the incorporation of demographic data from participants is crucial for ensuring the inclusiveness of representative populations, identifying at-risk groups, and addressing healthcare disparities. Drawing on both research experiences and the existing literature, this article provides recommendations for researchers aiming to undertake efficient and impactful projects involving invasive human samples. The suggested strategies include: (1) establishing productive collaborations with clinicians; (2) optimizing sample quality through meticulous collection and handling procedures; and (3) strategically implementing a retrospective model to capitalize on existing invasive sample repositories. When established, cooperative work between clinical health care workers and biological anthropologists can yield insights into human biology that have the potential to improve human health and wellbeing.

Ethics and applications of isotope analysis in archaeology

This synthesis explores specific ethical questions that commonly arise in isotopic analysis. For more than four decades, isotope analysis has been employed in archeological studies to explore past human and animal dietary habits, mobility patterns, and the environment in which a human or animal inhabited during life. These analyses require consideration of ethical issues. While theoretical concepts are discussed, we focus on practical aspects: working with descendant communities and other rights holders, choosing methods, creating and sharing data, and working mindfully within academia. These layers of respect and care should surround our science. This paper is relevant for specialists in isotope analysis as well as those incorporating these methods into larger projects. By covering the whole of the research process, from design to output management, we appeal broadly to archaeology and provide actionable solutions that build on the discussions in the general field.

Positionality statements in science

The goal of this essay is to clarify positionality as an epistemological scientific concept and address related misunderstandings to help researchers assess whether statements thereof contribute to their work. Positionality statements can be useful for various research designs across scientific fields, when they are used knowingly.

Gendered conflict in the human family

Sexual conflict is a thriving area of animal behaviour research. Yet parallel research in the evolutionary human sciences remains underdeveloped and has become mired by controversy. In this special collection, we aim to invigorate the study of fitness-relevant conflicts between women and men, advocating for three synergistic research priorities. First, we argue that a commitment to diversity is required to innovate the field, achieve ethical research practice, and foster fruitful dialogue with neighbouring social sciences. Accordingly, we have prioritised issues of diversity as editors, aiming to stimulate new connections and perspectives. Second, we call for greater recognition that human sex/gender roles and accompanying conflict behaviours are both subject to natural selection and culturally determined. This motivates our shift in terminology from sexual to gendered conflict when addressing human behaviour, countering stubborn tendencies to essentialise differences between women and men and directing attention to the role of cultural practices, normative sanctions and social learning in structuring conflict battlegrounds. Finally, we draw attention to contemporary policy concerns, including the wellbeing consequences of marriage practices and the gendered implications of market integration. Focus on these themes, combined with attendance to the dangers of ethnocentrism, promises to inform culturally sensitive interventions promoting gender equality worldwide.

Sexual minority status is associated with earlier recalled age of menarche: Evidence from the 2005-2016 National Health and Nutrition Examination Survey

INTRODUCTION

Menarcheal timing is associated with growth, development, health, wellbeing, and reproduction across the lifespan. Although sexual orientation is a known correlate of health and developmental inequities, relatively little evolutionarily framed research has investigated sexual orientation-based variation in maturational timing. To improve our understanding of menarcheal timing among sexual minority (SM) people, we use a biocultural-evolutionary life history lens that takes into account the stresses of minoritization to examine the relationship between sexual orientation and self-reported age at menarche in a sample of American adults.

METHODS

Using the U.S. National Health and Nutrition Examination Survey (NHANES), a large, nationally representative dataset (n = 9757), we fit multiple logistic regression models and survival curves to evaluate associations between sexual orientation, indicators of somatic and material resources during adolescence (e.g., education, citizenship, upper arm length), and self-reported menarche.

RESULTS

SM respondents were more likely to report earlier (by 4-5 months) ages of menarche (p < .001). Post-hoc tests revealed that these differences were driven by bisexual (p < .001) and same-sex experienced (p < .001) relative to heterosexual and lesbian/gay respondents. Earlier menarcheal timing among SM respondents persisted after adjusting for socio-demographic factors and proxies of developmental conditions.

DISCUSSION

Our findings reveal that SM status is associated with earlier ages of menarche, an important social and reproductive milestone. We argue that uniting life history theory with the minority stress hypothesis better explains differences in menarcheal timing by sexual orientation than previous paradigms. Investigators should attend to sexual orientation-based variation in maturational timing using holistic, inclusive approaches.

Toolkit article: Approaches to measuring social inequities in health in human biology research

Across populations, human morbidity and mortality risks generally follow clear gradients, with socially-disadvantaged individuals and groups tending to have higher morbidity and mortality at all life stages relative to those more socially advantaged. Anthropologists specialize in understanding the proximate and ultimate factors that shape variation in human biological functioning and health and are therefore well-situated to explore the relationships between social position and health in diverse ecological and cultural contexts. While human biologists have developed sophisticated methods for assessing health using minimally-invasive methods, at a disciplinary level, we have room for conceptual and methodological improvement in how we frame, measure, and analyze the social inequities that might shape health inequities. This toolkit paper elaborates on some steps human biologists should take to enhance the quality of our research on health inequities. Specifically, we address: (1) how to frame unequal health outcomes (i.e., inequalities vs. disparities vs. inequities) and the importance of identifying our conceptual models of how these inequities emerge; (2) how to measure various axes of social inequities across diverse cultural contexts, and (3) approaches to community collaboration and dissemination. We end by discussing (4) future directions in human biology research of health inequities, including understanding the ultimate causes of sensitivity to social inequities and transitioning from research to action.

Discrepancies in infant feeding recommendations between grandmothers and healthcare providers in rural Mexico

BACKGROUND

Infant feeding practices are rapidly changing within rural areas in Mexico, including indigenous communities. The aim of this study was to compare infant feeding recommendations between grandmothers and healthcare providers, to better understand the factors that may influence these practices within these communities. This study builds on research that recognizes the legacy of colonization as an ongoing process that impacts the lives of people through many pathways, including the substandard healthcare systems available to them.

METHODS

Qualitative study based on secondary data analysis from interviews and focus groups guided by a socioecological framework conducted in 2018 in two rural, Indigenous communities in Central Mexico. Participants were purposively selected mothers (n = 25), grandmothers (n = 11), and healthcare providers (n = 24) who offered care to children up to two years of age and/or their mothers. Data were coded and thematically analyzed to contrast the different perspectives of infant feeding recommendations and practices between mother, grandmothers, and healthcare providers.

RESULTS

Grandmothers and healthcare providers differed in their beliefs regarding appropriate timing to introduce non-milk foods and duration of breastfeeding. Compared to grandmothers, healthcare providers tended to believe that their recommendations were superior to those from people in the communities and expressed stereotypes reflected in negative attitudes towards mothers who did not follow their recommendations. Grandmothers often passed down advice from previous generations and their own experiences with infant feeding but were also open to learning from healthcare providers through government programs and sharing their knowledge with their daughters and other women. Given the contradictory recommendations from grandmothers and healthcare providers, mothers often were unsure which advice to follow.

CONCLUSIONS

There are important differences between grandmothers and healthcare providers regarding infant feeding recommendations. Healthcare providers may perceive their recommendations as superior given the neocolonial structures of the medical system. Public health policies are needed to address the different recommendations mothers receive from different sources, by harmonizing them and following an evidence-informed approach. Breastfeeding programs need to value and to seek the participation of grandmothers.

Minimally invasive biomarkers in human population biology research, part 2: An introduction to the special issue

Over the past several decades, biomarkers have become indispensable tools in human biology, allowing researchers to investigate biocultural and evolutionary questions and to generate basic data on health and well-being. Human biologists are central players in biomarker methods development, pioneering the creation of "field friendly," minimally invasively collected biomarker approaches, as well as leading the innovative use of biomarkers, most notably to map the complex pathways from social and environmental conditions to altered physiology to health effects. This special issue, Part 2 of a collection focused on minimally invasively collected biomarkers, is comprised of nine papers that jointly contribute to driving the science of biomarker methods development and application. This compilation of papers engages with topics such as biological normalcy, ecoimmunology, and the ethics of working with vulnerable and underserved populations. It also focuses attention on research areas at present not emphasized in human biology such as bone turnover markers as a window onto osteoporosis and osteoarthritis and the use of cancer-related biomarkers in population screening and epidemiology. Taken together, these papers help draw the roadmap for future biomarker work, emphasizing: (1) the need for systematic and transparent approaches to assay validation, with open access publication; (2) simultaneous measurement of multiple biomarkers and expanded use of instrument platforms that increase the range of physiological, genomics, and omics markers available to researchers; and, (3) increased attention to ethics and researcher responsibilities, encouraging a mindset that recognizes our obligation to provide benefits to individuals and communities and to help redress past abuses.