1
|
DuBois LZ, Shattuck-Heidorn H. Challenging the binary: Gender/sex and the bio-logics of normalcy. Am J Hum Biol 2021; 33:e23623. [PMID: 34096131 DOI: 10.1002/ajhb.23623] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Revised: 04/08/2021] [Accepted: 05/18/2021] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND We are witnessing renewed debates regarding definitions and boundaries of human gender/sex, where lines of genetics, gonadal hormones, and secondary sex characteristics are drawn to defend strict binary categorizations, with attendant implications for the acceptability and limits of gender identity and diversity. AIMS Many argue for the need to recognize the entanglement of gender/sex in humans and the myriad ways that gender experience becomes biology; translating this theory into practice in human biology research is essential. Biological anthropology is well poised to contribute to these societal conversations and debates. To do this effectively, a reconsideration of our own conceptions of gender/sex, gender identity, and sexuality is necessary. METHODS In this article, we discuss biological variation associated with gender/sex and propose ways forward to ensure we are engaging with gender/sex diversity. We base our analysis in the concept of "biological normalcy," which allows consideration of the relationships between statistical distributions and normative views. We address the problematic reliance on binary categories, the utilization of group means to represent typical biologies, and document ways in which binary norms reinforce stigma and inequality regarding gender/sex, gender identity, and sexuality. DISCUSSION AND CONCLUSIONS We conclude with guidelines and methodological suggestions for how to engage gender/sex and gender identity in research. Our goal is to contribute a framework that all human biologists can use, not just those who work with gender or sexually diverse populations. We hope that in bringing this perspective to bear in human biology, that novel ideas and applications will emerge from within our own discipline.
Collapse
Affiliation(s)
- L Zachary DuBois
- Department of Anthropology, University of Oregon, Eugene, Oregon, USA
| | | |
Collapse
|
2
|
Sabbi KH, Emery Thompson M, Machanda ZP, Otali E, Wrangham RW, Muller MN. Sex differences in early experience and the development of aggression in wild chimpanzees. Proc Natl Acad Sci U S A 2021; 118:e2017144118. [PMID: 33727418 PMCID: PMC8000022 DOI: 10.1073/pnas.2017144118] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Sex differences in physical aggression occur across human cultures and are thought to be influenced by active sex role reinforcement. However, sex differences in aggression also exist in our close evolutionary relatives, chimpanzees, who do not engage in active teaching, but do exhibit long juvenile periods and complex social systems that allow differential experience to shape behavior. Here we ask whether early life exposure to aggression is sexually dimorphic in wild chimpanzees and, if so, whether other aspects of early sociality contribute to this difference. Using 13 y of all-occurrence aggression data collected from the Kanyawara community of chimpanzees (2005 to 2017), we determined that young male chimpanzees were victims of aggression more often than females by between 4 and 5 (i.e., early in juvenility). Combining long-term aggression data with data from a targeted study of social development (2015 to 2017), we found that two potential risk factors for aggression-time spent near adult males and time spent away from mothers-did not differ between young males and females. Instead, the major risk factor for receiving aggression was the amount of aggression that young chimpanzees displayed, which was higher for males than females throughout the juvenile period. In multivariate models, sex did not mediate this relationship, suggesting that other chimpanzees did not target young males specifically, but instead responded to individual behavior that differed by sex. Thus, social experience differed by sex even in the absence of explicit gender socialization, but experiential differences were shaped by early-emerging sex differences in behavior.
Collapse
Affiliation(s)
- Kris H Sabbi
- Department of Anthropology, Tufts University, Medford, MA 02155;
- Department of Anthropology, University of New Mexico, Albuquerque, NM 87131
| | - Melissa Emery Thompson
- Department of Anthropology, University of New Mexico, Albuquerque, NM 87131
- Kibale Chimpanzee Project, Fort Portal, Uganda
| | - Zarin P Machanda
- Department of Anthropology, Tufts University, Medford, MA 02155
- Kibale Chimpanzee Project, Fort Portal, Uganda
| | - Emily Otali
- Kibale Chimpanzee Project, Fort Portal, Uganda
| | - Richard W Wrangham
- Kibale Chimpanzee Project, Fort Portal, Uganda
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA 87131
| | - Martin N Muller
- Department of Anthropology, University of New Mexico, Albuquerque, NM 87131
- Kibale Chimpanzee Project, Fort Portal, Uganda
| |
Collapse
|
3
|
|
4
|
Stewart FA, Pruetz JD. Sex Bias and Social Influences on Savanna Chimpanzee (Pan troglodytes verus) Nest Building Behavior. INT J PRIMATOL 2020. [DOI: 10.1007/s10764-020-00157-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
AbstractMany primates show sex differences in behavior, particularly social behavior, but also tool use for extractive foraging. All great apes learn to build a supportive structure for sleep. Whether sex differences exist in building, as in extractive foraging, is unknown, and little is known about how building skills develop and vary between individuals in the wild. We therefore aimed to describe the nesting behavior of savanna chimpanzees (Pan troglodytes verus) in Fongoli, Senegal to provide comparative data and to investigate possible sex or age differences in nest building behaviors and nest characteristics. We followed chimpanzee groups to their night nesting sites to record group (55 nights) and individual level data (17 individuals) on nest building initiation and duration (57 nests) during the dry season between October 2007 and March 2008. We returned the following morning to record nest and tree characteristics (71 nests built by 25 individuals). Fongoli chimpanzees nested later than reported for other great apes, but no sex differences in initiating building emerged. Observations were limited but suggest adult females and immature males to nest higher, in larger trees than adult males, and adult females to take longer to build than either adult or immature males. Smaller females and immature males may avoid predation or access thinner, malleable branches, by nesting higher than adult males. These differences suggest that sex differences described for chimpanzee tool use may extend to nest building, with females investing more time and effort in constructing a safe, warm structure for sleep than males do.
Collapse
|
5
|
Fuentes A. Identities, Experiences, and Beliefs: On Challenging Normativities in Biological Anthropology. AMERICAN ANTHROPOLOGIST 2019. [DOI: 10.1111/aman.13227] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
|
6
|
Lonsdorf EV. Sex differences in nonhuman primate behavioral development. J Neurosci Res 2017; 95:213-221. [PMID: 27870433 DOI: 10.1002/jnr.23862] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 07/11/2016] [Accepted: 07/11/2016] [Indexed: 12/22/2022]
Abstract
Sex differences in behavior and developmental trajectories in human children are of great interest to researchers in a variety of fields, and a persistent topic of discussion and debate is the relative contribution of biological vs. social influences to such differences. Given the potentially large effects of cultural and social influences on human child development, nonhuman primates are important model species for investigating the biological and evolutionary roots of sex differences in human development. This Mini-Review briefly summarizes the existing literature on sex-biased behavior toward infant nonhuman primates by mothers and other social partners, followed by a review of findings on sex differences (or lack thereof) in primate behavioral development from a variety of species in wild and naturalistic settings. These include differences in physical and social development, including play, grooming, and object manipulation patterns, as well as nursing and the development of foraging behavior. The Mini-Review concludes by providing potential avenues for future research. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Elizabeth V Lonsdorf
- Department of Psychology and Biological Foundations of Behavior Program, Franklin and Marshall College, Lancaster, Pennsylvania
| |
Collapse
|
7
|
Luoto S, Rantala MJ. Specificity of Women's Sexual Response: Proximate Mechanisms and Ultimate Causes. ARCHIVES OF SEXUAL BEHAVIOR 2017; 46:1195-1198. [PMID: 28224312 DOI: 10.1007/s10508-017-0961-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 02/11/2017] [Indexed: 06/06/2023]
Affiliation(s)
- Severi Luoto
- English, Drama and Writing Studies, University of Auckland, ARTS 1 - Bldg 206, Level 6, Room 616, 14A Symonds St, Auckland, 1010, New Zealand.
- School of Psychology, University of Auckland, Auckland, New Zealand.
| | - Markus J Rantala
- Department of Biology, University of Turku, Turku, Finland
- Turku Brain and Mind Center, University of Turku, Turku, Finland
| |
Collapse
|
8
|
Semenyna SW, Vasey PL. Bullying, Physical Aggression, Gender-Atypicality, and Sexual Orientation in Samoan Males. ARCHIVES OF SEXUAL BEHAVIOR 2017; 46:1375-1381. [PMID: 26801482 DOI: 10.1007/s10508-015-0676-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Revised: 11/27/2015] [Accepted: 11/30/2015] [Indexed: 06/05/2023]
Abstract
Bullying is characterized by the repeated attempts of a group or individual to gain social advantage by the use of relational, verbal, or physical aggression against a target, especially when there is a perceived or actual power imbalance (Espelage & Swearer, 2003). One consistent finding is that gay (i.e., androphilic) males report higher rates of victimization due to bullying in adolescence than their heterosexual (i.e., gynephilic) counterparts. Western data indicate that gender-atypical behavior, regardless of sexual orientation, is a key predictor of victimization due to bullying. Androphilic males generally display childhood gender-atypicality, including reduced levels of physical aggression, which may cause bullies to perceive them as "easy" targets. In order to test the associations between sexual orientation, childhood gender-atypicality, and recalled victimization due to bullying, a sample of Samoan gynephilic men (n = 100) were compared to a group of Samoan transgender androphilic males (n = 103), known as fa'afafine. Although the fa'afafine reported far more childhood gender-atypicality, the two groups did not differ significantly on measures of physical aggression or their reported rates of victimization due to bullying. Additionally, greater physical aggression, not gender-atypicality, was the only significant predictor of being bullied in both men and fa'afafine. These results suggest that there is nothing inherent in sexual orientation or childhood gender-atypicality that would potentiate victimization from bullying. Instead, the cultural context in which a bully functions influences the extent to which these are "acceptable" reasons to target certain individuals.
Collapse
Affiliation(s)
- Scott W Semenyna
- Department of Psychology, University of Lethbridge, C866 University Hall, 4401 University Drive, Lethbridge, AB, T1K 3M4, Canada.
| | - Paul L Vasey
- Department of Psychology, University of Lethbridge, C866 University Hall, 4401 University Drive, Lethbridge, AB, T1K 3M4, Canada
| |
Collapse
|
9
|
Dettmer AM, Murphy AM, Guitarra D, Slonecker E, Suomi SJ, Rosenberg KL, Novak MA, Meyer JS, Hinde K. Cortisol in Neonatal Mother's Milk Predicts Later Infant Social and Cognitive Functioning in Rhesus Monkeys. Child Dev 2017; 89:525-538. [PMID: 28369689 DOI: 10.1111/cdev.12783] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Milk provides not only the building blocks for somatic development but also the hormonal signals that contribute to the biopsychological organization of the infant. Among mammals, glucocorticoids (GCs) in mother's milk have been associated with infant temperament. This study extended prior work to investigate rhesus monkey (Macaca mulatta) mother-infant dyads (N = 34) from birth through 8 months postpartum. Regression analysis revealed that cortisol concentrations in milk during the neonatal period predicted impulsivity on a cognitive task, but not global social behaviors, months later. During this time period, sex-differentiated social behavior emerged. For female infants, milk cortisol concentrations predicted total frequency of play. Collectively, these findings support and extend the "lactational programming" hypothesis on the impact of maternal-origin hormones ingested via milk.
Collapse
Affiliation(s)
- Amanda M Dettmer
- Eunice Kennedy Shriver National Institute of Child Health & Human Development
| | - Ashley M Murphy
- Eunice Kennedy Shriver National Institute of Child Health & Human Development
| | - Denisse Guitarra
- Eunice Kennedy Shriver National Institute of Child Health & Human Development
| | - Emily Slonecker
- Eunice Kennedy Shriver National Institute of Child Health & Human Development
| | - Stephen J Suomi
- Eunice Kennedy Shriver National Institute of Child Health & Human Development
| | | | | | | | | |
Collapse
|
10
|
Simpson EA, Nicolini Y, Shetler M, Suomi SJ, Ferrari PF, Paukner A. Experience-independent sex differences in newborn macaques: Females are more social than males. Sci Rep 2016; 6:19669. [PMID: 26794858 PMCID: PMC4726418 DOI: 10.1038/srep19669] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 12/09/2015] [Indexed: 12/30/2022] Open
Abstract
Human females exhibit greater social interest and skills relative to males, appearing in infancy, suggesting biological roots; however, male and female infants may be treated differently, potentially causing or amplifying sex differences. Here, we tested whether sex differences in social motivation emerge in infant monkeys (n = 48) reared in a controlled postnatal environment. Compared to males, females at 2-3 weeks looked more at conspecifics' faces (d = 0.65), especially the eyes (d = 1.09), and at 4-5 weeks exhibited more affiliative behaviors (d = 0.64), including gesturing, looking, and proximity to familiar and unfamiliar human caretakers. In sum, converging evidence from humans and monkeys suggests that female infants are more social than males in the first weeks of life, and that such differences may arise independent of postnatal experience. Individual differences in social interest have wide-ranging developmental consequences, impacting infants' social interaction quality and opportunities for learning. Understanding the evolution of sex differences and their developmental emergence is necessary to best support infants with varying levels of sociality.
Collapse
Affiliation(s)
- Elizabeth A. Simpson
- Department of Psychology, University of Miami, Coral Gables, Florida, USA
- Laboratory of Comparative Ethology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services, Poolesville, Maryland, USA
- Dipartimento di Neuroscienze, Università di Parma, Parma, 4300 Italy
| | - Ylenia Nicolini
- Dipartimento di Neuroscienze, Università di Parma, Parma, 4300 Italy
| | - Melissa Shetler
- Unit on Computer Support Services, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland, USA
| | - Stephen J. Suomi
- Laboratory of Comparative Ethology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services, Poolesville, Maryland, USA
| | - Pier F. Ferrari
- Dipartimento di Neuroscienze, Università di Parma, Parma, 4300 Italy
| | - Annika Paukner
- Laboratory of Comparative Ethology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services, Poolesville, Maryland, USA
| |
Collapse
|
11
|
Semenyna SW, Vasey PL. Victimization due to bullying and physical aggression in Samoan men and women. PERSONALITY AND INDIVIDUAL DIFFERENCES 2015. [DOI: 10.1016/j.paid.2015.07.032] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|