Reading the Bones

In a Neolithic community in Turkey, bone loss in older men and women showed, surprisingly, no significant sex differences.

Excavated burial at Çatalhöyük of a female individual with fetus. Many young adult female skeletons at Çatalhöyük, such as this one, show unusually low percentages of cortical bone and high turnover, which could be indicative of transient reproductive stress.

Courtesy Çatalhöyük Research Project

Excerpted from Exploring Sex and Gender in Bioarchaeology, edited by Sabrina C. Agarwal and Julie K. Wesp. Published by University of New Mexico Press. Copyright © 2017 by University of New Mexico Press. All rights reserved.

The human skeleton is built over a lifetime, driven by internal physiological mechanisms and external behavior. The unique construction of the skeleton gives bioarchaeologists clues of past social and biological experiences.

Patterns of bone loss and fragility have been studied in archaeological remains with a focus on sex-related differences. Bone loss is widely regarded as occurring primarily in women with the onset of menopause, which is compounded with senescence of the body. While lifestyle factors, such as reproductive behavior (parity and/or breastfeeding) or diet, are considered to influence bonemaintenance, they are still only considered to be isolated agents that exacerbate the inevitable hormonal changes to the female skeleton. As such, indications of bone loss or osteoporosis are generally regarded to reflect the irreversible course of menopause and aging. However, the makeup and integrity of skeletal tissue and the whole skeleton are affected by multiple biocultural influences cumulatively over the entire life span.

The study of gender-based variation in bone morphology is hampered by several factors. The first is methodological. The consideration of gender in health and disease begins with and is tied to the assignment of biological sex. Bioarchaeologists first divide skeletal samples into biologically known, distinct sex groups. The subsequent analyses of social, political, or economic population-level change are almost always grounded in this initial sex assessment. The second factor is the focus on biocultural influences on bone morphology over a specific period of the life of an individual. Archaeological samples, obviously, do not permit looking at changes in morphology over a given individual’s life cycle. However, this is at odds with contemporary understandings of bone biology and the formation of skeletal morphology over the life cycle. Finally, the traditional focus on population-level data overshadows individual variation and hampers our ability to appreciate the fluidity of sex and gender—that socially constructed state of being a woman or man, which can vary from society to society and change over time, and is not universally mapped onto binary biological sex.

Dividing skeletal samples into male and female groups at the beginning of the analysis of data assumes that the most significant social difference is that of sex. However, I find that assignment makes it more difficult to appreciate the role of cross-cutting variables, such as age, race, or class. Further, biological sex frames our expectations and interpretations of gendered health in the past. For example, the health of women is often linked to their role as a “reproducer,” with the costs of childbearing and childrearing as focal points in the framing of health. Prehistoric women are often hypothesized to have suffered constantly from reproductive nutritional and metabolic stress, or to have reduced bone robusticity compared to males due to the limits on their mobility imposed by reproduction.

Although theoretical work has sought to critically address the dualities of biological sex and gender, there have been few studies that have explicitly explored this theoretical ground in conjunction with the analyses of actual skeletal remains. Some researchers have critically examined the assumed relationship between sex and gender, and others have focused on the limitation of binary biological sex and of the traditional use of “normal” heterosexual interpretations of gender roles from skeletal remains. This critical evaluation has allowed the identification of nonbinary genders—third and fourth genders—in the bioarchaeological record through skeletal indicators, such as degenerative joint disease or musculoskeletal stress markers, and gender-bending through archaeological contextualization.

Evidence of bone loss and fragility has been the classic gendered indicator of health. Bone loss has been used to identify both young and old females. Giving primacy to only biological determinants of bone loss and fragility, the collapsing of gender with sex in archaeological samples, and focusing explicitly on bone loss in only female skeletons—all of these limit our understanding of other potentially important biocultural influences on bone morphology. What is missing in bioarchaeology is the application of life course approaches that allows us to imagine gender identity in the past as a malleable and dynamic construction that is not locked in with biology. This has vital implications for how we interpret gendered indicators on the skeleton in our reconstructions of diet, activity, and disease.

The aged adult individual observed in the skeletal record is the creation of life experiences and the trajectories taken during growth; and, similarly, the young adult or child in the skeletal record shows a morphology that would have changed with events over the rest of the life cycle had they continued to live. Twenty-first-century biomedical and epidemiological studies have demonstrated how plasticity during growth and development can influence aspects of lifelong bone health, such as bone mineral density and loss. Infant and adolescent growth spurts seem to be highly influential in defining bone quality and quantity at later life stages. More important, the environmental situation early in life can interact with the genome to create the boundaries of growth and development for a given individual. For example, fetal programming by maternal undernutrition is a risk factor for low birth weight.

In population studies, individual variation is anticipated in analysis, but it is discounted in large aggregate data sources as noise. Small individual variances are accounted for (or perhaps lost) by large, normally distributed samples, or they are treated as statistical outliers. Paleopathology case studies have served to highlight individuals, but only to emphasize the unusual or a typically unseen advanced stage of disease. There have been noted case studies of bone loss and osteoporosis in archaeological skeletons, but the interpretation has been fixated on what is termed “typical” postmenopausal bone loss in females. These studies present a static view of gender, and what is lost is the more fluid texture of lived experience over the life course. I suggest that a multi-scaled approach, which simultaneously focuses on patterns in whole populations together with a contextual focus on outlier data points, can reveal a more holistic picture of gendered identity in the past. A case study of patterns of bone loss in a Neolithic archaeological population supports this thesis.

Artist rendering of Çatalhöyük (ca. 7400–6000 BCE) with its close-packed houses and rooftop entrances, located in south-central Anatolia about 50 kilometers from the modern city of Konya, Turkey. Individuals were buried within houses, notably under platforms and floors, placing the living both physically and symbolically with the dead.

Dan Lewandowski
Çatalhöyük is a large, late-Neolithic settlement site (ca. 7400–6000 BCE) first excavated by British archaeologist James Mellaart in the 1960s (currently under the direction of Ian Hodder, Director of the Çatalhöyük Archaeological Project). The site is located in south-central Anatolia about 50 kilometers from the modern city of Konya, Turkey. It is perhaps best known for its close-packed houses with rooftop entrances and remarkable paintings, reliefs, and installed bucrania. Individuals are buried within houses, notably under platforms and floors, although the dead were also placed in building foundations, infill, benches, and middens. These unique intramural burials placed the living both physically and symbolically with the dead. At the peak of its occupation, Çatalhöyük is estimated to have had a population size between 3,500 and 8,000. Over the years, study of the human remains has been a large collaborative effort, which has contributed much to our understandingof social structure, health, diet, and lifestyle at Çatalhöyük. I specifically focus here on the sex-related patterns of bone turnover and loss that are relevant to the discussion of gendered life at Çatalhöyük.

Several parameters of bone turnover have been examined at Çatalhöyük, including the amount and turnover of cortical bone of the rib and the second metacarpal (hand bone). The rib is more indicative of the amount of bone present and of remodeling in the decades prior todeath, whereas the metacarpal is a site influenced more by biomechanical activity (use of hands) and reflects both bone gain accumulated in youth and bone lost over the life cycle. Human burials included in the analysis span the early through late periods of the site’s occupancy, with the majority recovered from the middle period, which is thought to correspond with “peak” occupation size and density. Only adults were included in the analysis, with individuals divided into three broad age cohorts: young adults (20–29 years), mature adults (30–49 years), and older adults (50+ years). 

In the rib, the amount of bone (measured as a percentage of cortical bone) does show an age-related trend, with females showing a reduction in the amount of bone by middle age, while males show a reduction in bone by old age. However, there is only a significant sex difference in middle age, while in old age both sexes appear to show the same amount of bone in the rib. The same trend is observed in indicators of bone turnover in the rib. Both sexes show a reduction of bone turnover by old age, with the oldest age group showing the lowest values in formation and activation. This is an age-expected trend in human bone turnover, since metabolic activity turns down with age. What is interesting in both measures of bone loss in the rib is the lack of sex differences in old age, with both men and women at Çatalhöyük showing similar levels of bone turnover. This is a highly surprising observation, given that women in western modern populations typically show much lower bone turnover compared to men in old age due to the compounding influence of menopause. Similar levels of bone turnover at Çatalhöyük suggest that males and females had overall similar health and activity patterns.

In the metacarpal bone of the hand, the patterns of bone loss at Çatalhöyük are more similar to what is observed in modern populations: both sexes show lower bone amount in the oldest age category.

However, here again, there is no significant sex difference in older age.

Cortical bone loss in the rib and metacarpal at Çatalhöyük suggests significant bone loss in those over 50 years of age, particularly females, leading to reduced amounts of compact bone. This patternof bone maintenance and loss with age is well documented in modern and several archaeological populations. In nearly all bioarchaeological studies this pattern of loss is typically interpreted as reflecting either pathological stress or expected menopausal bone loss. However, there are subtle but important differences in the pattern of bone loss seen at Çatalhöyük compared to modern populations: specifically, the similar percentage of cortical bone in males and females over 50 years of age, and the loss of bone in young adult females.

If I shift the focus to individual outliers, the unusually low levels of bone and high bone turnover in young adult females could be indicative of reproductive stress. Isotope analyses indicate that the weaning age at Çatalhöyük began at 18 months with cessation of breastfeeding at about 3 years. Most women of reproductive age would likely have been pregnant or breastfeeding at the time of death. This could account for the loss of bone and the high metabolic turnover in young adults. For example, a young adult female skeleton in the sample has one of the lowest cortical bone values in the rib and metacarpal. This individual was found with a fetus and likely died during childbirth. Her bone loss could be related to the metabolic demands of pregnancy, but what is key is that this bone loss would have been transient. That there is no long-term disadvantage to the skeleton from reproductive stress is suggested by a return to higher bone values in the oldest age group and the lack of sex difference in old age. There are also several female individuals in the oldest age category with expected low rib cortical bone values, but significantly higher than mean metacarpal bone values. This could reflect the biomechanical influence of use on the small long bones of the hand, which would have crafted the cortical thickness of the bone over the entire life course. Outlier individuals such as these highlight the complex roles of both biological senescence and behavior on bone maintenance across different skeletal sites. The maintenance of bone mass in the hands of several women at the same level as men, even in old age, again suggests that daily physical activities, or at least the intensity of activities, were not highly gendered.

Two other outlier individuals in the rib and metacarpal bone maintenance data set are also noteworthy: a male and a female both estimated to be over 50 years of age. Both individuals have nearly identical bone values with a high degree of age-related loss of bone, indicative of not only living to a similar old age, but of a lack of highly gendered lifestyles. These two burials had a large array of mortuary goods. The older female had several unusual items, notably three incised boar tusks placed on the body, which could have been jewelry or part of a garment. The older male also had a number of unusual finds associated with him, including a bone hook placed on the chest and a cluster of five flint tools and an antler tool, with some of the flint tools showing significant wear and others appearing quite new. Nearly all primary adult burials of individuals over 50 years old have been found with artifacts. The large number of personalized items in these burials suggests that sex was not a marker of difference, but that age and individual identity likely were. We cannot use the biological traces of bone maintenance to reconstruct specific activities and social roles. However, it is relevant that skeletons highly individuated in burial treatment and burial goods are also the most individuated skeletons as shown through indicators of bone loss. Clusters or individual outliers in mean values or data patterning are not only telling of variation in biological aging, but together with contextual information they contribute to our understanding of social age and gender.

The evidence for a lack of a strictly gendered lifestyle at Çatalhöyük is also supported by bioarchaeological data on diet, trauma, nonspecific infection, and dental disease, which show little or no significant difference between men and women. The data presented here do not imply that biological sex was not a reality at Çatalhöyük, but the combined bioarchaeological data suggest that social roles in life and death were not defined strictly by sex. The examination of age as an axis of difference in the skeletal and material evidence serves to better refine our focus on gendered differences in the skeletal data. While there are little striking over-all sex differences in bone loss and in most other skeletal indicators at Çatalhöyük, age is a cross-cutting variable that is key.

With the great interest in the role of women in early agricultural settlements, early excavation and interpretation of material culture at Çatalhöyük suggested gender differences in power with a fixation on mother goddess imagery. For many decades, Çatalhöyük was considered an ideal example of the early matriarchal society thought typical across Europe with the spread of agriculture. However, recent research on the human remains from the site, including data on diet, disease, and trauma, suggest minimal difference in lifestyles between the sexes, although some of the biological data do mark sexual dimorphism in the community. Simultaneously, work on funerary practices, imagery, and variability in figurines and burial goods has emphasized more complex interpretations of gendered identity. Since the amount of bone we accrue and lose is affected by experiences over the life course, similar bone maintenance between males and females suggests that daily life was not highly gendered, at least not along the lines of biological sex as modern societies have conceived it. While pregnancy and breastfeeding may have caused females to have transient lower levels of bone during reproductive periods, this does not seem to have had a negative effect on women’s long-term skeletal health.

The human skeleton is constructed over time. It is the product of lived experience crafted at the tissue level from the moment of conception to death. Simultaneous observations at both the population and individual levels in the archaeological record can be used to reconstruct the actions that have uniquely molded the bodies that we study. It allows us to observe variations in bone morphology asindicators with a rich depth of time, variations that are formed over life  cycles and generations and that emphasize human beings as products of engagement with their social worlds.   --SCA

Recent Stories

Satellite monitoring and networks of instruments on the ground can detect, but not predict, volcanic eruptions.

Doing something about the weather is no longer just talk.

Neuroscientists are beginning to understand the connections.

The long-dormant site of Spain’s first environmental protest in 1888, revisited.