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Walker RS, Flinn MV, Prall SP, Hamilton MJ. Remote sensing evidence for population growth of isolated indigenous societies in Amazonia. Sci Rep 2023; 13:22448. [PMID: 38105308 PMCID: PMC10725865 DOI: 10.1038/s41598-023-50127-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Accepted: 12/15/2023] [Indexed: 12/19/2023] Open
Abstract
Isolated indigenous societies who actively avoid sustained peaceful contact with the outside world are critically endangered. Last year, "Tanaru", the lone surviving man of his tribe for at least 35 years, died in Southwest Amazonia, marking the latest cultural extinction event in a long history of massacres, enslavement, and epidemics. Yet in the upper reaches of the Amazon Basin, dozens of resilient isolated tribes still manage to survive. Remote sensing is a reliable method of monitoring the population dynamics of uncontacted populations by quantifying the area cleared for gardens and villages, along with the fire detections associated with the burning of those clearings. Remote sensing also provides a method to document the number of residential structures and village fissioning. Only with these longitudinal assessments can we better evaluate the current no-contact policies by the United Nations and governments, along with the prospects for the long-term survival of isolated tribes. While the world's largest isolated indigenous metapopulation, Pano speakers in Acre, Brazil, appears to be thriving, other smaller isolated populations disconnected from metapopulations continue to be extremely vulnerable to external threats. Our applied anthropological conservation approach is to provide analyses of publicly available remote sensing datasets to help inform policies that enhance the survival and well-being of isolated cultural groups.
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Affiliation(s)
- Robert S Walker
- Department of Anthropology, University of Missouri, Columbia, MO, USA.
| | - Mark V Flinn
- Department of Anthropology, Baylor University, Waco, TX, USA
| | - Sean P Prall
- Department of Anthropology, University of Missouri, Columbia, MO, USA
| | - Marcus J Hamilton
- Department of Anthropology, University of Texas at San Antonio, San Antonio, TX, USA
- School of Data Science, University of Texas at San Antonio, San Antonio, TX, USA
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Abstract
A major evolutionary transition in individuality involves the formation of a cooperative group and the transformation of that group into an evolutionary entity. Human cooperation shares principles with those of multicellular organisms that have undergone transitions in individuality: division of labour, communication, and fitness interdependence. After the split from the last common ancestor of hominoids, early hominins adapted to an increasingly terrestrial niche for several million years. We posit that new challenges in this niche set in motion a positive feedback loop in selection pressure for cooperation that ratcheted coevolutionary changes in sociality, communication, brains, cognition, kin relations and technology, eventually resulting in egalitarian societies with suppressed competition and rapid cumulative culture. The increasing pace of information innovation and transmission became a key aspect of the evolutionary niche that enabled humans to become formidable cooperators with explosive population growth, the ability to cooperate and compete in groups of millions, and emergent social norms, e.g. private property. Despite considerable fitness interdependence, the rise of private property, in concert with population explosion and socioeconomic inequality, subverts potential transition of human groups into evolutionary entities due to resurgence of latent competition and conflict. This article is part of the theme issue 'Human socio-cultural evolution in light of evolutionary transitions'.
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Affiliation(s)
- Cathryn Townsend
- Department of Anthropology, Baylor University, Waco, TX 76798-7334, USA
| | - Joseph V. Ferraro
- Department of Anthropology, Baylor University, Waco, TX 76798-7334, USA
| | - Heather Habecker
- Department of Psychology and Neuroscience, Baylor University, Waco, TX 76798-7334, USA
| | - Mark V. Flinn
- Department of Anthropology, Baylor University, Waco, TX 76798-7334, USA
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Crespi BJ, Flinn MV, Summers K. Runaway Social Selection in Human Evolution. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.894506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Darwin posited that social competition among conspecifics could be a powerful selective pressure. Alexander proposed a model of human evolution involving a runaway process of social competition based on Darwin’s insight. Here we briefly review Alexander’s logic, and then expand upon his model by elucidating six core arenas of social selection that involve runaway, positive-feedback processes, and that were likely involved in the evolution of the remarkable combination of adaptations in humans. We discuss how these ideas fit with the hypothesis that a key life history innovation that opened the door to runaway social selection, and cumulative culture, during hominin evolution was increased cooperation among individuals in small fission-fusion groups.
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Woo S, Flinn MV. Traditional Postpartum Care Among Women of Korean Descent in the United States. Matern Child Health J 2022; 26:1871-1880. [PMID: 35142941 DOI: 10.1007/s10995-022-03378-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/20/2022] [Indexed: 11/29/2022]
Abstract
OBJECTIVES Traditional postpartum care practices in East Asia have been recognized as non-functional by some government public health agencies. This study examined the perception of traditional postpartum care practice among families of Korean descent in the United States. In addition to pragmatic health care issues, the research was designed to contribute to cross-cultural understanding of hot-cold theory of reproductive behavior. METHODS A descriptive survey study and follow-up interviews were conducted among women of Korean descent living in the United States (n = 141). A questionnaire was used to explore the variation in women's beliefs about traditional postpartum care and the extent to which they or their relatives practiced this care. In the follow-up interview, the participants freely described the different ways of postpartum care practice. RESULTS Compared to women from other Asian and immigrant populations, women of Korean descent maintained similar or higher rates of believing the functionality of temperature maintenance care practice, and believed that the associated forms of traditional care will continue in the future. CONCLUSIONS FOR PRACTICE Traditional postpartum care practices are broadly shared and practiced in Asian immigrant populations, even in highly industrialized and modernized settings. Furthermore, from their own experience of somatic pain and its functionality, women called for better implementation of traditional care as an alternative or supplement to modern medical care. Health-care systems need to improve understanding and accommodation of cultural beliefs about possible benefits of temperature maintenance after childbirth in Asian ethnic populations.
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Affiliation(s)
- Sangkwon Woo
- Seoul National University of Science and Technology, 232 Gongneung-ro, Nowon-gu, Seoul, 01811, Republic of Korea
| | - Mark V Flinn
- Department of Anthropology, Baylor University, MMSCI 264, Waco, TX, 76798, USA.
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Abstract
Creativity generates novel solutions to tasks by processing information. Imagination and mental representations are part of the creative process; we can mull over ideas of our own making, and construct algorithms or scenarios from them. Social scenario-building can be viewed as a human cognitive "super-power" that involves abstraction, meta-representation, time-travel, and directed imaginative thought. We humans have a "theater in our minds" to play out a near-infinite array of social strategies and contingencies. Here we propose an integrative model for why and how humans evolved extraordinary creative abilities. We posit that a key aspect of hominin evolution involved relatively open and fluid social relationships among communities, enabled by a unique extended family structure similar to that of contemporary hunter-gatherer band societies. Intercommunity relationships facilitated the rapid flow of information-"Culture"-that underpinned arms-races in information processing, language, imagination, and creativity that distinguishes humans from other species.
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Affiliation(s)
- Mark V. Flinn
- Department of Anthropology, Baylor University, Waco, TX, United States
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Keith MH, Flinn MV, Durbin HJ, Rowan TN, Blomquist GE, Taylor KH, Taylor JF, Decker JE. Genetic ancestry, admixture, and population structure in rural Dominica. PLoS One 2021; 16:e0258735. [PMID: 34731205 PMCID: PMC8565749 DOI: 10.1371/journal.pone.0258735] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 10/04/2021] [Indexed: 12/23/2022] Open
Abstract
The Caribbean is a genetically diverse region with heterogeneous admixture compositions influenced by local island ecologies, migrations, colonial conflicts, and demographic histories. The Commonwealth of Dominica is a mountainous island in the Lesser Antilles historically known to harbor communities with unique patterns of migration, mixture, and isolation. This community-based population genetic study adds biological evidence to inform post-colonial narrative histories in a Dominican horticultural village. High density single nucleotide polymorphism data paired with a previously compiled genealogy provide the first genome-wide insights on genetic ancestry and population structure in Dominica. We assessed family-based clustering, inferred global ancestry, and dated recent admixture by implementing the fastSTRUCTURE clustering algorithm, modeling graph-based migration with TreeMix, assessing patterns of linkage disequilibrium decay with ALDER, and visualizing data from Dominica with Human Genome Diversity Panel references. These analyses distinguish family-based genetic structure from variation in African, European, and indigenous Amerindian admixture proportions, and analyses of linkage disequilibrium decay estimate admixture dates 5–6 generations (~160 years) ago. African ancestry accounts for the largest mixture components, followed by European and then indigenous components; however, our global ancestry inferences are consistent with previous mitochondrial, Y chromosome, and ancestry marker data from Dominica that show uniquely higher proportions of indigenous ancestry and lower proportions of African ancestry relative to known admixture in other French- and English-speaking Caribbean islands. Our genetic results support local narratives about the community’s history and founding, which indicate that newly emancipated people settled in the steep, dense vegetation along Dominica’s eastern coast in the mid-19th century. Strong genetic signals of post-colonial admixture and family-based structure highlight the localized impacts of colonial forces and island ecologies in this region, and more data from other groups are needed to more broadly inform on Dominica’s complex history and present diversity.
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Affiliation(s)
- Monica H. Keith
- Department of Anthropology, University of Missouri, Columbia, Missouri, United States of America
- * E-mail: (MHK); (JED)
| | - Mark V. Flinn
- Department of Anthropology, University of Missouri, Columbia, Missouri, United States of America
| | - Harly J. Durbin
- Division of Animal Sciences, University of Missouri, Columbia, Missouri, United States of America
| | - Troy N. Rowan
- Division of Animal Sciences, University of Missouri, Columbia, Missouri, United States of America
- Genomics Center for the Advancement of Agriculture, University of Tennessee Institute for Agriculture, Knoxville, Tennessee, United States of America
| | - Gregory E. Blomquist
- Department of Anthropology, University of Missouri, Columbia, Missouri, United States of America
| | - Kristen H. Taylor
- Department of Anatomy and Pathological Sciences, University of Missouri, Columbia, Missouri, United States of America
| | - Jeremy F. Taylor
- Division of Animal Sciences, University of Missouri, Columbia, Missouri, United States of America
| | - Jared E. Decker
- Division of Animal Sciences, University of Missouri, Columbia, Missouri, United States of America
- * E-mail: (MHK); (JED)
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Ponzi D, Flinn MV, Muehlenbein MP, Nepomnaschy PA. Hormones and human developmental plasticity. Mol Cell Endocrinol 2020; 505:110721. [PMID: 32004677 DOI: 10.1016/j.mce.2020.110721] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 11/11/2019] [Accepted: 01/16/2020] [Indexed: 12/15/2022]
Abstract
Natural selection favors the evolution of mechanisms that optimize the allocation of resources and time among competing traits. Hormones mediate developmental plasticity, the changes in the phenotype that occur during ontogeny. Despite their highly conserved functions, the flexibilities of human hormonal systems suggest a strong history of adaptation to variable environments. Physiological research on developmental plasticity has focused on the early programming effects of stress, the hypothalamus-pituitary-adrenal axis (HPAA) and the hypothalamus-pituitary-gonadal axis (HPGA) during critical periods, when the hormones produced have the strongest influence on the developing brain. Often this research emphasizes the maladaptive effects of early stressful experiences. Here we posit that the HPAA and HPAG systems in human developmental plasticity have evolved to be responsive to complex and dynamic problems associated with human sociality. The lengthy period of human offspring dependency, and its associated brain development and risks, is linked to the uniquely human combination of stable breeding bonds, extensive paternal effort in a multi-male group, extended bilateral kin recognition, grandparenting, and controlled exchange of mates among kin groups. We evaluate an evolutionary framework that integrates proximate physiological explanations with ontogeny, phylogeny, adaptive function, and comparative life history data.
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Affiliation(s)
- Davide Ponzi
- Unit of Neuroscience, Department of Medicine and Surgery, University of Parma, Italy.
| | - Mark V Flinn
- Department of Anthropology, Baylor University, Waco, TX, USA
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Keith MH, Blomquist GE, Flinn MV. Anthropometric heritability and child growth in a Caribbean village: A quantitative genetic analysis of longitudinal height, weight, and body mass index in Bwa Mawego, Dominica. Am J Phys Anthropol 2019; 170:393-403. [PMID: 31460671 DOI: 10.1002/ajpa.23924] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 07/31/2019] [Accepted: 08/06/2019] [Indexed: 12/21/2022]
Abstract
OBJECTIVES Body size and composition vary widely among individuals and populations, and long-term research in diverse contexts informs our understanding of genetic, cultural, and environmental impacts on this variation. We analyze longitudinal measures of height, weight, and body mass index (BMI) from a Caribbean village, estimating the extent to which these anthropometrics are shaped by genetic variance in a small-scale population of mixed ancestry. MATERIALS AND METHODS Longitudinal data from a traditionally horticultural village in Dominica document height and weight in a non-Western population that is transitioning to increasingly Westernized lifestyles, and an 11-generation pedigree enables us to estimate the proportions of phenotypic variation in height, weight, and BMI attributed to genetic variation. We assess within-individual variation across growth curves as well as heritabilities of these traits for 260 individuals using Bayesian variance component estimation. RESULTS Age, sex, and secular trends account for the majority of anthropometric variation in these longitudinal data. Independent of age, sex, and secular trends, our analyses show high repeatabilities for the remaining variation in height, weight, and BMI growth curves (>0.75), and moderate heritabilities (h2 height = 0.68, h2 weight = 0.64, h2 BMI = 0.49) reveal clear genetic signals that account for large proportions of the variation in body size observed between families. Secular trends show increases of 6.5% in height and 16.0% in weight from 1997 to 2017. DISCUSSION This horticultural Caribbean population has transitioned to include more Westernized foods and technologies over the decades captured in this analysis. BMI varies widely between individuals and is significantly shaped by genetic variation, warranting future exploration with other physiological correlates and associated genetic variants.
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Affiliation(s)
- Monica H Keith
- Department of Anthropology, University of Missouri, Columbia, Missouri
| | | | - Mark V Flinn
- Department of Anthropology, University of Missouri, Columbia, Missouri
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Chagnon NA, Lynch RF, Shenk MK, Hames R, Flinn MV. Cross-cousin marriage among the Yanomamö shows evidence of parent-offspring conflict and mate competition between brothers. Proc Natl Acad Sci U S A 2017; 114:E2590-E2607. [PMID: 28289230 PMCID: PMC5380100 DOI: 10.1073/pnas.1618655114] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Marriage in many traditional societies often concerns the institutionalized exchange of reproductive partners among groups of kin. Such exchanges most often involve cross-cousins-marriage with the child of a parent's opposite-sex sibling-but it is unclear who benefits from these exchanges. Here we analyze the fitness consequences of marrying relatives among the Yanomamö from the Amazon. When individuals marry close kin, we find that (i) both husbands and wives have slightly lower fertility; (ii) offspring suffer from inbreeding depression; (iii) parents have more grandchildren; and (iv) siblings, especially brothers, benefit when their opposite-sex siblings marry relatives but not when their same-sex siblings do. Therefore, individuals seem to benefit when their children or opposite-sex siblings marry relatives but suffer costs when they, their parents, or same-sex siblings do. These asymmetric fitness outcomes suggest conflicts between parents and offspring and among siblings over optimal mating strategies. Parental control of marriages is reinforced by cultural norms prescribing cross-cousin marriage. We posit that local mate competition combined with parental control over marriages may escalate conflict between same-sex siblings who compete over mates, while simultaneously forging alliances between opposite-sex siblings. If these relationships are carried forward to subsequent generations, they may drive bilateral cross-cousin marriage rules. This study provides insights into the evolutionary importance of how kinship and reciprocity underlie conflicts over who controls mate choice and the origins of cross-cousin marriage prescriptions.
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Affiliation(s)
- Napoleon A Chagnon
- Department of Anthropology, University of Missouri, Columbia, MO 65211-1440;
| | - Robert F Lynch
- Department of Anthropology, University of Missouri, Columbia, MO 65211-1440
| | - Mary K Shenk
- Department of Anthropology, University of Missouri, Columbia, MO 65211-1440
| | - Raymond Hames
- Department of Anthropology, University of Nebraska, Lincoln, NE 68588-0368
| | - Mark V Flinn
- Department of Anthropology, University of Missouri, Columbia, MO 65211-1440
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Abstract
Patterns of human kinship commonly involve preferential treatment of relatives based on lineal descent (lineages) rather than degree of genetic relatedness (kindreds), presenting a challenge for inclusive fitness theory. Here, we examine effects of lineage and kindred characteristics on reproductive success (RS) and number of grandchildren for 130 men and 124 women in a horticultural community on Dominica. Kindreds had little effect on fitness independently of lineage characteristics. Fitness increased with the number of lineal relatives residing in the community but decreased beyond an apparently optimal lineage size, suggesting resource enhancement and competition among kin. Female-biased patrilineage sex ratio was positively associated with men's fitness, while male-biased matrilineage sex ratio was positively associated with women's fitness. Number of brothers in the community was negatively associated with men's, but not women's, fitness. Parents and number of sisters had no effect on either male or female reproduction; however, women with younger sisters had higher RS, suggesting benefits of kin support for childcare. In sum, imposed norms for lineage social organization may enhance lineal ancestors' inclusive fitness at a cost to individual inclusive fitness.
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Affiliation(s)
- Robert J Quinlan
- Anthropology Department, Ball State University, 47306, Muncie, IN.
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Abstract
In recent years there has been a growing interest in the use of social network analysis in biobehavioral research. Despite the well-established importance of social relationships in influencing human behavior and health, little is known about how children's perception of their immediate social relationships correlates with biological parameters of stress. In this study we explore the association between two measures of children's personal social networks, perceived network size and perceived network density, with two biomarkers of stress, cortisol and salivary alpha-amylase. Forty children (mean age = 8.30, min age = 5, and max age = 12) were interviewed to collect information about their friendships and three samples of saliva were collected. Our results show that children characterized by a lower pre-interview cortisol concentration and a lower salivary alpha-amylase reactivity to the interview reported the highest density of friendships. We discuss this result in light of the multisystem approach to the study of children's behavioral outcomes, emphasizing that future work of this kind is needed in order to understand the cognitive and biological mechanisms underlying children's and adolescents' social perceptual biases.
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Affiliation(s)
- Davide Ponzi
- a Division of Biological Sciences , University of Missouri , Columbia , MS 65201 , USA
| | | | - David C Geary
- c Department of Psychological Sciences , University of Missouri , Columbia , MS 65201 , USA
| | - Mark V Flinn
- d Department of Anthropology , University of Missouri , Columbia , MS 65201 , USA
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Brenner SL, Jones JP, Rutanen-Whaley RH, Parker W, Flinn MV, Muehlenbein MP. Evolutionary Mismatch and Chronic Psychological Stress. ACTA ACUST UNITED AC 2015. [DOI: 10.4303/jem/235885] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Abstract
Some cross-cultural evidence suggests lethal coalitionary aggression in humans is the product of residence and descent rules that promote fraternal interest groups, i.e., power groups of coresident males bonded by kinship. As such, human lethal coalitions are hypothesized to be homologous to chimpanzee (Pan troglodytes) border patrols. However, humans demonstrate a unique metagroup social structure in which strategic alliances allow individuals to form coalitions transcending local community boundaries. We test predictions derived from the fraternal interest group and strategic alliance models using lethal coalition data from a lowland South American population, the Yanomamö. Yanomamö men who kill an enemy acquire a special status, termed unokai. We examine the social characteristics of co-unokais or men who jointly kill others. Analyses indicate co-unokais generally are (i) from the same population but from different villages and patrilines, (ii) close age mates, and (iii) maternal half-first cousins. Furthermore, the incident rate for co-unokai killings increases if men are similar in age, from the same population, and from different natal communities. Co-unokais who have killed more times in the past and who are more genetically related to each other have a higher probability of coresidence in adulthood. Last, a relationship exists between lethal coalition formation and marriage exchange. In this population, internal warfare unites multiple communities, and co-unokais strategically form new residential groups and marriage alliances. These results support the strategic alliance model of coalitionary aggression, demonstrate the complexities of human alliance formation, and illuminate key differences in social structure distinguishing humans from other primates.
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Affiliation(s)
- Shane J Macfarlan
- Department of Anthropology, University of Utah, Salt Lake City, UT 84112; and
| | - Robert S Walker
- Department of Anthropology, University of Missouri, Columbia, MO 65211
| | - Mark V Flinn
- Department of Anthropology, University of Missouri, Columbia, MO 65211
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Walker RS, Beckerman S, Flinn MV, Gurven M, von Rueden CR, Kramer KL, Greaves RD, Córdoba L, Villar D, Hagen EH, Koster JM, Sugiyama L, Hunter TE, Hill KR. Living with Kin in Lowland Horticultural Societies. Current Anthropology 2013. [DOI: 10.1086/668867] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Flinn MV. Book review. Am J Hum Biol 2011. [DOI: 10.1002/ajhb.21169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Abstract
Background The universality of marriage in human societies around the world suggests a deep evolutionary history of institutionalized pair-bonding that stems back at least to early modern humans. However, marriage practices vary considerably from culture to culture, ranging from strict prescriptions and arranged marriages in some societies to mostly unregulated courtship in others, presence to absence of brideservice and brideprice, and polyandrous to polygynous unions. The ancestral state of early human marriage is not well known given the lack of conclusive archaeological evidence. Methodology Comparative phylogenetic analyses using data from contemporary hunter-gatherers around the world may allow for the reconstruction of ancestral human cultural traits. We attempt to reconstruct ancestral marriage practices using hunter-gatherer phylogenies based on mitochondrial DNA sequences. Results Arranged marriages are inferred to go back at least to first modern human migrations out of Africa. Reconstructions are equivocal on whether or not earlier human marriages were arranged because several African hunter-gatherers have courtship marriages. Phylogenetic reconstructions suggest that marriages in early ancestral human societies probably had low levels of polygyny (low reproductive skew) and reciprocal exchanges between the families of marital partners (i.e., brideservice or brideprice). Discussion Phylogenetic results suggest a deep history of regulated exchange of mates and resources among lineages that enhanced the complexity of human meta-group social structure with coalitions and alliances spanning across multiple residential communities.
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Affiliation(s)
- Robert S Walker
- Department of Anthropology, University of Missouri, Columbia, Missouri, United States of America.
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Flinn MV, Nepomnaschy PA, Muehlenbein MP, Ponzi D. Evolutionary functions of early social modulation of hypothalamic-pituitary-adrenal axis development in humans. Neurosci Biobehav Rev 2011; 35:1611-29. [PMID: 21251923 DOI: 10.1016/j.neubiorev.2011.01.005] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2010] [Revised: 12/17/2010] [Accepted: 01/05/2011] [Indexed: 02/07/2023]
Abstract
The hypothalamic-pituitary-adrenal axis (HPAA) is highly responsive to social challenges. Because stress hormones can have negative developmental and health consequences, this presents an evolutionary paradox: Why would natural selection have favored mechanisms that elevate stress hormone levels in response to psychosocial stimuli? Here we review the hypothesis that large brains, an extended childhood and intensive family care in humans are adaptations resulting from selective forces exerted by the increasingly complex and dynamic social and cultural environment that co-evolved with these traits. Variations in the modulation of stress responses mediated by specific HPAA characteristics (e.g., baseline cortisol levels, and changes in cortisol levels in response to challenges) are viewed as phenotypically plastic, ontogenetic responses to specific environmental signals. From this perspective, we discuss relations between physiological stress responses and life history trajectories, particularly the development of social competencies. We present brief summaries of data on hormones, indicators of morbidity and social environments from our long-term, naturalistic studies in both Guatemala and Dominica. Results indicate that difficult family environments and traumatic social events are associated with temporal elevations of cortisol, suppressed reproductive functioning and elevated morbidity. The long-term effects of traumatic early experiences on cortisol profiles are complex and indicate domain-specific effects, with normal recovery from physical stressors, but some heightened response to negative-affect social challenges. We consider these results to be consistent with the hypothesis that developmental programming of the HPAA and other neuroendocrine systems associated with stress responses may facilitate cognitive targeting of salient social challenges in specific environments.
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Affiliation(s)
- Mark V Flinn
- Department of Anthropology, University of Missouri, 107 Swallow Hall, Columbia, MO 65211, USA.
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Vigil JM, Geary DC, Granger DA, Flinn MV. Sex differences in salivary cortisol, alpha-amylase, and psychological functioning following Hurricane Katrina. Child Dev 2010; 81:1228-40. [PMID: 20636692 DOI: 10.1111/j.1467-8624.2010.01464.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The study examines group and individual differences in psychological functioning and hypothalamic-pituitary-adrenal and sympathetic nervous system (SNS) activity among adolescents displaced by Hurricane Katrina and living in a U.S. government relocation camp (n = 62, ages 12-19 years) 2 months postdisaster. Levels of salivary cortisol, salivary alpha-amylase, depression, anxiety, distress, aggression, and self-esteem for this group were contrasted with a demographically matched no-trauma control group (n = 53). Results revealed that hurricane exposure and SNS activity moderated the relations between lower cortisol and higher internalizing behaviors. Sex-related differences were observed in behavioral adjustment and stress regulation. Implications of sex differences in biobehavioral adjustment to loss, displacement, and relocation are discussed in relation to evolutionary and developmental theory.
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Affiliation(s)
- Jacob M Vigil
- Department of Psychology, University of New Mexico, 1 University of New Mexico, MSC03 2220, Albuquerque, NM 87131-1161, USA.
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Nepomnaschy PA, Vitzthum VJ, Flinn MV. Evolutionary endocrinology: integrating proximate mechanisms, ontogeny, and evolved function. Introduction. Am J Hum Biol 2010; 21:728-30. [PMID: 19367572 DOI: 10.1002/ajhb.20924] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Affiliation(s)
- P A Nepomnaschy
- Faculty of Health Sciences, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6.
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Abstract
Taylor and colleagues proposed that women uniquely respond to stressors by tending to children and befriending other women rather than by fighting or fleeing (S. E. Taylor et al., 2000). In this article, the authors expand Taylor et al.'s evolutionary frame and incorporate several unique aspects of human social dynamics. First, humans are characterized by extensive paternal investment, and thus men's tending is predicted and observed in some stressful contexts. Second, the dynamics of women's befriending suggest an evolutionary elaboration of the mechanisms that support reciprocal altruism. Third, coalitional male-male competition indicates that men's befriending is a predicted component of their fight-or-flight response. Finally, men's tending should result in the evolution of female-female competition over this form of parental investment.
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Affiliation(s)
- David C Geary
- Department of Psychological Sciences, University of Missouri, Columbia 65211-2500, USA.
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Flinn MV, Altemeier WA. Why do we have IgE-mediated immediate hypersensitivity? Pediatr Ann 2000; 29:731. [PMID: 11211852 DOI: 10.3928/0090-4481-20001201-03] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Abstract
This study examines socioeconomic conditions, psychosocial stress, and health among 264 infants, children, adolescents, and young adults aged 2 months to 18 years residing in a rural Caribbean village. Fieldwork was conducted over a 9 year period (1988-1996). Research methods and techniques include salivary cortisol radioimmunoassay (N = 22,438), systematic behavioral observations, psychological questionnaires, health evaluations, medical records, informal interviews, and participant observation. Analyses of data indicate complex relations among socioeconomic conditions, stress, and health. Household income, land ownership, parental education, and other socioeconomic measures are weakly associated with child illness. There is no evidence that apparent material benefits of high socioeconomic status--such as improved housing, diet, work loads, and access to private healthcare--have important direct effects on child health in this population. However, social relationships, especially family environment, may have important effects on childhood psychosocial stress and illness. Abnormal glucocorticoid response profiles, diminished immunity, and frequent illness are associated with unstable mating relationships for parents/caretakers and household composition. We suggest that family relationships and concomitant stress and immunosuppression are important intermediary links between socioeconomic conditions and child health.
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Affiliation(s)
- M V Flinn
- Department of Anthropology, University of Missouri, Columbia 65211, USA
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Flinn MV, Quinlan RJ, Decker SA, Turner MT, England BG. Male-female differences in effects of parental absence on glucocorticoid stress response. Human Nature 1996; 7:125-62. [DOI: 10.1007/bf02692108] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/1995] [Accepted: 01/04/1996] [Indexed: 12/15/2022]
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Flinn MV. : Evolution Through Group Selection . V. C. Wynne-Edwards. American Anthropologist 1987. [DOI: 10.1525/aa.1987.89.3.02a00280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Flinn MV, Hausfater G, Hrdy SB. Infanticide: Comparative and Evolutionary Perspectives. Anthropological Quarterly 1985. [DOI: 10.2307/3317919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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