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Burkart JM, van Schaik C, Griesser M. Looking for unity in diversity: human cooperative childcare in comparative perspective. Proc Biol Sci 2018; 284:rspb.2017.1184. [PMID: 29237848 DOI: 10.1098/rspb.2017.1184] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 11/13/2017] [Indexed: 01/31/2023] Open
Abstract
Humans engage in cooperative childcare, which includes some elements not found in other animals, such as the presence of post-reproductive helpers, extensive food sharing among adults and a pervasive sexual division of labour. In animals, cooperative offspring care has typically been studied in two different contexts. The first mainly involves helpers contributing care in cooperatively breeding family groups; the second context is allomaternal care in species usually not categorized as cooperative breeders (e.g. plural and communal breeders, often without male care). Comparative analyses suggest that cooperative breeding and allomaternal care in plural and communal breeders have distinct evolutionary origins, with humans fitting neither pathway entirely. Nevertheless, some critical proximate mechanisms of helping, including hormonal regulators, are likely to be shared across species. Other mechanisms may vary among species, such as social tolerance, proactive prosociality or conditional mother-infant bonding. These are presumably associated with specific details of the care system, such as whether all group members contribute, or whether mothers can potentially raise offspring alone. Thus, cooperative offspring care is seen in different contexts across animal lineages, but may nonetheless share several important psychological characteristics. We end by discussing how work on humans may play a unifying role in studying cooperative offspring care.
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Affiliation(s)
- Judith M Burkart
- Department of Anthropology, University of Zurich, Zurich, Switzerland
| | - Carel van Schaik
- Department of Anthropology, University of Zurich, Zurich, Switzerland
| | - Michael Griesser
- Department of Anthropology, University of Zurich, Zurich, Switzerland.,Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, Krakow 30-387, Poland
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52
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French JA, Cavanaugh J, Mustoe AC, Carp SB, Womack SL. Social Monogamy in Nonhuman Primates: Phylogeny, Phenotype, and Physiology. JOURNAL OF SEX RESEARCH 2018; 55:410-434. [PMID: 28704071 PMCID: PMC6004613 DOI: 10.1080/00224499.2017.1339774] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Monogamy as a social system has been both a scientific puzzle and a sociocultural issue for decades. In this review, we examine social monogamy from a comparative perspective with a focus on primates, our closest genetic relatives. We break down monogamy into component elements, including pair-bonding and partner preference, mate guarding or jealousy, social attachment, and biparental care. Our survey of primates shows that not all features are present in species classified as socially monogamous, in the same way that human monogamous relationships may not include all elements-a perspective we refer to as "monogamy à la carte." Our review includes a survey of the neurobiological correlates of social monogamy in primates, exploring unique or common pathways for the elemental components of monogamy. This compilation reveals that the components of monogamy are modulated by a suite of androgenic steroids, glucocorticoid hormones, the nonapeptide hormones oxytocin and vasopressin, and other neurotransmitter systems (e.g., dopamine and opioids). We propose that efforts to understand the biological underpinnings of complex human and animal sociosexual relationships will be well served by exploring individual phenotypic traits, as opposed to pursuing these questions with the assumption that monogamy is a unitary trait or a species-specific characteristic.
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Affiliation(s)
- Jeffrey A French
- a Department of Psychology and Department of Biology , University of Nebraska Omaha
| | - Jon Cavanaugh
- b Department of Psychology , University of Nebraska Omaha
| | - Aaryn C Mustoe
- b Department of Psychology , University of Nebraska Omaha
| | - Sarah B Carp
- b Department of Psychology , University of Nebraska Omaha
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53
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Nishida AH, Ochman H. Rates of gut microbiome divergence in mammals. Mol Ecol 2018; 27:1884-1897. [PMID: 29290090 PMCID: PMC5935551 DOI: 10.1111/mec.14473] [Citation(s) in RCA: 139] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 12/14/2017] [Accepted: 12/14/2017] [Indexed: 12/13/2022]
Abstract
The variation and taxonomic diversity among mammalian gut microbiomes raises several questions about the factors that contribute to the rates and patterns of change in these microbial communities. By comparing the microbiome compositions of 112 species representing 14 mammalian orders, we assessed how host and ecological factors contribute to microbiome diversification. Except in rare cases, the same bacterial phyla predominate in mammalian gut microbiomes, and there has been some convergence of microbiome compositions according to dietary category across all mammalians lineages except Chiropterans (bats), which possess high proportions of Proteobacteria and tend to be most similar to one another regardless of diet. At lower taxonomic ranks (families, genera, 97% OTUs), bacteria are more likely to be associated with a particular mammalian lineage than with a particular dietary category, resulting in a strong phylogenetic signal in the degree to which microbiomes diverge. Despite different physiologies, the gut microbiomes of several mammalian lineages have diverged at roughly the same rate over the past 75 million years; however, the gut microbiomes of Cetartiodactyla (ruminants, whales, hippopotami) have evolved much faster and those of Chiropterans much slower. Contrary to expectations, the number of dietary transitions within a lineage does not influence rates of microbiome divergence, but instead, some of the most dramatic changes are associated with the loss of bacterial taxa, such as those accompanying the transition from terrestrial to marine lifestyles and the evolution of hominids.
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Affiliation(s)
- Alex H Nishida
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, USA
| | - Howard Ochman
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, USA
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54
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Horrell ND, Hickmott PW, Saltzman W. Neural Regulation of Paternal Behavior in Mammals: Sensory, Neuroendocrine, and Experiential Influences on the Paternal Brain. Curr Top Behav Neurosci 2018; 43:111-160. [PMID: 30206901 DOI: 10.1007/7854_2018_55] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Across the animal kingdom, parents in many species devote extraordinary effort toward caring for offspring, often risking their lives and exhausting limited resources. Understanding how the brain orchestrates parental care, biasing effort over the many competing demands, is an important topic in social neuroscience. In mammals, maternal care is necessary for offspring survival and is largely mediated by changes in hormones and neuropeptides that fluctuate massively during pregnancy, parturition, and lactation (e.g., progesterone, estradiol, oxytocin, and prolactin). In the relatively small number of mammalian species in which parental care by fathers enhances offspring survival and development, males also undergo endocrine changes concurrent with birth of their offspring, but on a smaller scale than females. Thus, fathers additionally rely on sensory signals from their mates, environment, and/or offspring to orchestrate paternal behavior. Males can engage in a variety of infant-directed behaviors that range from infanticide to avoidance to care; in many species, males can display all three behaviors in their lifetime. The neural plasticity that underlies such stark changes in behavior is not well understood. In this chapter we summarize current data on the neural circuitry that has been proposed to underlie paternal care in mammals, as well as sensory, neuroendocrine, and experiential influences on paternal behavior and on the underlying circuitry. We highlight some of the gaps in our current knowledge of this system and propose future directions that will enable the development of a more comprehensive understanding of the proximate control of parenting by fathers.
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Affiliation(s)
- Nathan D Horrell
- Graduate Program in Neuroscience, University of California, Riverside, Riverside, CA, USA
- Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, Riverside, CA, USA
| | - Peter W Hickmott
- Graduate Program in Neuroscience, University of California, Riverside, Riverside, CA, USA
- Department of Psychology, University of California, Riverside, Riverside, CA, USA
| | - Wendy Saltzman
- Graduate Program in Neuroscience, University of California, Riverside, Riverside, CA, USA.
- Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, Riverside, CA, USA.
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55
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Zilioli S, Bird BM. Functional significance of men's testosterone reactivity to social stimuli. Front Neuroendocrinol 2017; 47:1-18. [PMID: 28676436 DOI: 10.1016/j.yfrne.2017.06.002] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 06/13/2017] [Accepted: 06/26/2017] [Indexed: 01/07/2023]
Abstract
Rapid testosterone fluctuations in response to social stimuli are observed across a wide range of species, and the highly conserved nature of these fluctuations suggests an adaptive function. This paper reviews the current literature on testosterone reactivity, primarily in human males, and illustrates how life-history theory provides an adequate theoretical framework to interpret findings. The review is structured around supporting evidence suggesting that situations implicated in mating effort either directly (e.g., interactions with a mate) or indirectly (e.g., intrasexual competition) are generally associated with a brief elevation of testosterone, while situations implicated in parenting effort (e.g., nurturant interactions with offspring) are generally associated with a decline in testosterone. Further, we discuss how these fluctuations in testosterone have been linked to future behaviors, and how situational, motivational, and physiological variables moderate the interplay between social stimuli, testosterone reactivity, and behavior. Supporting the notion that testosterone can play a causal role in modulating behavior in response to social stimuli, we also summarize recent single administration studies examining the effects of testosterone on physiology, neurobiology, and behavior. A conceptual model provides links between supported findings, and hypothesized pathways requiring future testing.
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Affiliation(s)
- Samuele Zilioli
- Department of Psychology, Wayne State University, Detroit, MI 48202, USA; Department of Family Medicine and Public Health Sciences, Wayne State University, Detroit, MI 48202, USA.
| | - Brian M Bird
- Department of Psychology, Simon Fraser University, Burnaby, BC V5A 1S6, Canada.
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56
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Saxbe DE, Schetter CD, Simon CD, Adam EK, Shalowitz MU. High paternal testosterone may protect against postpartum depressive symptoms in fathers, but confer risk to mothers and children. Horm Behav 2017; 95:103-112. [PMID: 28757312 DOI: 10.1016/j.yhbeh.2017.07.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2017] [Revised: 07/21/2017] [Accepted: 07/26/2017] [Indexed: 01/04/2023]
Abstract
Following the birth of an infant, decreases in testosterone and increases in depressive symptoms have been observed in fathers. Paternal testosterone may reflect fathers' investment in pair-bonding and paternal caregiving and, as such, may be associated with maternal and familial well-being. This study tests associations between paternal testosterone, paternal and maternal postpartum depressive symptoms, and subsequent family functioning. Within 149 couples, fathers provided testosterone samples when infants were approximately nine months old and both parents reported on postpartum depressive symptoms at two, nine, and 15months postpartum. Fathers with lower aggregate testosterone reported more depressive symptoms at two and nine months postpartum. Mothers whose partners had higher evening testosterone reported more depressive symptoms at nine and 15months postpartum. Maternal relationship satisfaction mediated this effect, such that mothers with higher testosterone partners reported more relationship dissatisfaction, which in turn predicted more maternal depressive symptoms. Higher paternal testosterone and paternal depressive symptoms at nine months postpartum each independently predicted greater fathering stress at 15months postpartum. Higher paternal testosterone also predicted more mother-reported intimate partner aggression at 15months postpartum. In addition to linear relationships between testosterone and depression, curvilinear relationships emerged such that fathers with both low and high testosterone at nine months postpartum reported more subsequent (15-month) depressive symptoms and fathering stress. In conclusion, whereas higher paternal testosterone may protect against paternal depression, it contributed to maternal distress and suboptimal family outcomes in our sample. Interventions that supplement or alter men's testosterone may have unintended consequences for family well-being.
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Affiliation(s)
- Darby E Saxbe
- Department of Psychology, University of Southern California, Los Angeles, CA 90089, USA.
| | | | - Clarissa D Simon
- NorthShore University HealthSystem Research Institute, Evanston, IL 60208, USA
| | - Emma K Adam
- School of Education and Social Policy and Institute for Policy Research, Northwestern University, Evanston, IL 60208, USA
| | - Madeleine U Shalowitz
- NorthShore University HealthSystem Research Institute, Evanston, IL 60208, USA; University of Chicago, Pritzker School of Medicine, Chicago, IL 60637, USA
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57
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Ziegler TE, Crockford C. Neuroendocrine control in social relationships in non-human primates: Field based evidence. Horm Behav 2017; 91:107-121. [PMID: 28284710 PMCID: PMC6372243 DOI: 10.1016/j.yhbeh.2017.03.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 03/06/2017] [Accepted: 03/07/2017] [Indexed: 11/22/2022]
Abstract
Primates maintain a variety of social relationships and these can have fitness consequences. Research has established that different types of social relationships are unpinned by different or interacting hormonal systems, for example, the neuropeptide oxytocin influences social bonding, the steroid hormone testosterone influences dominance relationships, and paternal care is characterized by high oxytocin and low testosterone. Although the oxytocinergic system influences social bonding, it can support different types of social bonds in different species, whether pair bonds, parent-offspring bonds or friendships. It seems that selection processes shape social and mating systems and their interactions with neuroendocrine pathways. Within species, there are individual differences in the development of the neuroendocrine system: the social environment individuals are exposed to during ontogeny alters their neuroendocrine and socio-cognitive development, and later, their social interactions as adults. Within individuals, neuroendocrine systems can also have short-term effects, impacting on social interactions, such as those during hunting, intergroup encounters or food sharing, or the likelihood of cooperating, winning or losing. To understand these highly dynamic processes, extending research beyond animals in laboratory settings to wild animals living within their natural social and ecological setting may bring insights that are otherwise unreachable. Field endocrinology with neuropeptides is still emerging. We review the current status of this research, informed by laboratory studies, and identify questions particularly suited to future field studies. We focus on primate social relationships, specifically social bonds (mother-offspring, father-offspring, cooperative breeders, pair bonds and adult platonic friendships), dominance, cooperation and in-group/out-group relationships, and examine evidence with respect to the 'tend and defend' hypothesis.
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Affiliation(s)
- Toni E Ziegler
- Wisconsin National Primate Research Center, University of Wisconsin, Madison, WI, USA.
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58
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Muller MN. Testosterone and reproductive effort in male primates. Horm Behav 2017; 91:36-51. [PMID: 27616559 PMCID: PMC5342957 DOI: 10.1016/j.yhbeh.2016.09.001] [Citation(s) in RCA: 93] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 09/06/2016] [Accepted: 09/07/2016] [Indexed: 10/21/2022]
Abstract
Considerable evidence suggests that the steroid hormone testosterone mediates major life-history trade-offs in vertebrates, promoting mating effort at the expense of parenting effort or survival. Observations from a range of wild primates support the "Challenge Hypothesis," which posits that variation in male testosterone is more closely associated with aggressive mating competition than with reproductive physiology. In both seasonally and non-seasonally breeding species, males increase testosterone production primarily when competing for fecund females. In species where males compete to maintain long-term access to females, testosterone increases when males are threatened with losing access to females, rather than during mating periods. And when male status is linked to mating success, and dependent on aggression, high-ranking males normally maintain higher testosterone levels than subordinates, particularly when dominance hierarchies are unstable. Trade-offs between parenting effort and mating effort appear to be weak in most primates, because direct investment in the form of infant transport and provisioning is rare. Instead, infant protection is the primary form of paternal investment in the order. Testosterone does not inhibit this form of investment, which relies on male aggression. Testosterone has a wide range of effects in primates that plausibly function to support male competitive behavior. These include psychological effects related to dominance striving, analgesic effects, and effects on the development and maintenance of the armaments and adornments that males employ in mating competition.
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Affiliation(s)
- Martin N Muller
- Department of Anthropology, University of New Mexico, United States.
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59
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Saxbe DE, Edelstein RS, Lyden HM, Wardecker BM, Chopik WJ, Moors AC. Fathers' decline in testosterone and synchrony with partner testosterone during pregnancy predicts greater postpartum relationship investment. Horm Behav 2017; 90:39-47. [PMID: 27469070 DOI: 10.1016/j.yhbeh.2016.07.005] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 07/12/2016] [Accepted: 07/15/2016] [Indexed: 12/16/2022]
Abstract
The transition to parenthood has been associated with declines in testosterone among partnered fathers, which may reflect males' motivation to invest in the family. Moreover, preliminary evidence has found that couples show correlations in hormone levels across pregnancy that may also be linked to fathers' preparation for parenthood. The current study used repeated-measures sampling of testosterone across pregnancy to explore whether fathers' change in T, and correlations with mothers' T, were associated with fathers' and mothers' postpartum investment. In a sample of 27 couples (54 individuals) expecting their first child, both parents' salivary testosterone was measured multiple times across pregnancy. At approximately 3.5months postpartum, participants rated their investment, commitment, and satisfaction with their partner. A multilevel model was used to measure change in testosterone over time and associations between mother and father testosterone. Fathers who showed stronger declines in T across pregnancy, and stronger correlations with mothers' testosterone, reported higher postpartum investment, commitment, and satisfaction. Mothers reported more postpartum investment and satisfaction if fathers showed greater prenatal declines in T. These results held even after controlling for paternal investment, commitment, and satisfaction measured prenatally at study entry. Our results suggest that changes in paternal testosterone across pregnancy, and hormonal linkage with the pregnant partner, may underlie fathers' dedication to the partner relationship across the transition to parenthood.
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Affiliation(s)
- Darby E Saxbe
- Department of Psychology, University of Southern California, 3620 McClintock Ave, Los Angeles, CA 90089, USA.
| | - Robin S Edelstein
- Department of Psychology, University of Michigan, 530 Church Street, Ann Arbor, MI 49109, USA.
| | - Hannah M Lyden
- Department of Psychology, University of Southern California, 3620 McClintock Ave, Los Angeles, CA 90089, USA.
| | - Britney M Wardecker
- Department of Psychology, University of Michigan, 530 Church Street, Ann Arbor, MI 49109, USA.
| | - William J Chopik
- Department of Psychology, Michigan State University, 316 Physics Rd., East Lansing, MI 48824, USA.
| | - Amy C Moors
- National Center for Institutional Diversity and Energy Institute, University of Michigan, Ann Arbor, MI 49109, USA.
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60
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Rilling JK, Mascaro JS. The neurobiology of fatherhood. Curr Opin Psychol 2017; 15:26-32. [PMID: 28813264 DOI: 10.1016/j.copsyc.2017.02.013] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 02/10/2017] [Indexed: 12/11/2022]
Abstract
Only about 5% of mammalian species exhibit paternal caregiving in nature, and paternal behavior has evolved multiple times independently among mammals. The most parsimonious way to evolve paternal behavior may be to utilize pre-existing neural systems that are in place for maternal behavior. Despite evidence for similarity in the neurobiology of maternal and paternal behavior in rodents, paternal behavior also has its own dedicated neural circuitry in some species. Human fathers engage conserved subcortical systems that motivate caregiving in rodent parents and human mothers, as well as cortical systems involved with empathy that they share with human mothers. Finally, paternal behavior is modulated by similar hormones and neuropeptides in rodents, non-human primates, and humans.
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Affiliation(s)
- James K Rilling
- Department of Anthropology, Emory University, 207 Anthropology Building, 1557 Dickey Drive, Atlanta, Georgia 30322, USA; Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, 1639 Pierce Drive, Suite 4000, Atlanta, Georgia 30322, USA; Center for Behavioral Neuroscience, Emory University, PO Box 3966, Atlanta, Georgia 30302, USA; Center for Translational Social Neuroscience, Emory University, USA.
| | - Jennifer S Mascaro
- Center for Translational Social Neuroscience, Emory University, USA; Department of Family and Preventive Medicine, Emory University School of Medicine, 1841 Clifton Road NE, Rm 507, Atlanta, GA 30329, USA
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61
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Gettler LT, Sarma MS, Gengo RG, Oka RC, McKenna JJ. Adiposity, CVD risk factors and testosterone: Variation by partnering status and residence with children in US men. Evol Med Public Health 2017; 2017:67-80. [PMID: 28435680 PMCID: PMC5397396 DOI: 10.1093/emph/eox005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Indexed: 12/12/2022] Open
Abstract
Background and objectives: In many settings, partnered, invested fathers have lower testosterone than single men or fathers who are not involved in caregiving. Reduced testosterone has been identified as a risk factor for multiple chronic diseases, and men's health also commonly varies by life history status. There have been few tests of whether variation in testosterone based on partnering and parenting has implications for men's health. Methodology: We analysed data from a US population-representative sample (NHANES) of young-to-middle aged US men (n = 875; mean age: 29.8 years ± 6.0 [SD]). We tested for life history status differences in testosterone, adiposity levels and biomarkers of cardiovascular disease (CVD)-risk (HDL cholesterol; triglycerides; white blood cell count [WBC]). Results: Partnered men residing with children (RC) had lower testosterone and elevated abdominal adiposity compared to never married men not residing with children. While they did not significantly differ for WBC or triglycerides, partnered RC men also had comparatively lower HDL. Partnered RC males' lower testosterone accounted for their relatively elevated adiposity, but testosterone, adiposity, and health-related covariates did not explain their relatively reduced HDL. Conclusions and implications: Our results linking life history status-based differences in testosterone and adiposity, alongside our complementary HDL findings, indicate that testosterone-related psychobiology might have implications for partnered RC men's CVD risk in the US and other similar societal settings. These types of socially contextualized observations of men's health and physiological function particularly merit incorporation in clinical discussions of fatherhood as a component of men's health.
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Affiliation(s)
- Lee T Gettler
- Department of Anthropology, University of Notre Dame, Notre Dame, IN, USA
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA
| | - Mallika S Sarma
- Department of Anthropology, University of Notre Dame, Notre Dame, IN, USA
| | - Rieti G Gengo
- Department of Anthropology, University of Notre Dame, Notre Dame, IN, USA
- Helen B. Kellogg Institute for International Studies, University of Notre Dame, Notre Dame, IN, USA
| | - Rahul C Oka
- Department of Anthropology, University of Notre Dame, Notre Dame, IN, USA
- Helen B. Kellogg Institute for International Studies, University of Notre Dame, Notre Dame, IN, USA
| | - James J McKenna
- Department of Anthropology, University of Notre Dame, Notre Dame, IN, USA
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62
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Gettler LT, Ryan CP, Eisenberg DTA, Rzhetskaya M, Hayes MG, Feranil AB, Bechayda SA, Kuzawa CW. The role of testosterone in coordinating male life history strategies: The moderating effects of the androgen receptor CAG repeat polymorphism. Horm Behav 2017; 87:164-175. [PMID: 27794482 DOI: 10.1016/j.yhbeh.2016.10.012] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2016] [Revised: 10/20/2016] [Accepted: 10/23/2016] [Indexed: 02/08/2023]
Abstract
Partnered fathers often have lower testosterone than single non-parents, which is theorized to relate to elevated testosterone (T) facilitating competitive behaviors and lower T contributing to nurturing. Cultural- and individual-factors moderate the expression of such psychobiological profiles. Less is known about genetic variation's role in individual psychobiological responses to partnering and fathering, particularly as related to T. We examined the exon 1 CAG (polyglutamine) repeat (CAGn) within the androgen receptor (AR) gene. AR CAGn shapes T's effects after it binds to AR by affecting AR transcriptional activity. Thus, this polymorphism is a strong candidate to influence individual-level profiles of "androgenicity." While males with a highly androgenic profile are expected to engage in a more competitive-oriented life history strategy, low androgenic men are at increased risk of depression, which could lead to similar outcomes for certain familial dynamics, such as marriage stability and parenting. Here, in a large longitudinal study of Filipino men (n=683), we found that men who had high androgenicity (elevated T and shorter CAGn) or low androgenicity (lower T and longer CAGn) showed elevated likelihood of relationship instability over the 4.5-year study period and were also more likely be relatively uninvolved with childcare as fathers. We did not find that CAGn moderated men's T responses to the fatherhood transition. In total, our results provide evidence for invested fathering and relationship stability at intermediate levels of androgenicity and help inform our understanding of variation in male reproductive strategies and the individual hormonal and genetic differences that underlie it.
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Affiliation(s)
- Lee T Gettler
- Department of Anthropology, University of Notre Dame, Notre Dame, IN, United States; The Eck Institute for Global Health, University of Notre Dame, United States.
| | - Calen P Ryan
- Department of Anthropology, Northwestern University, Evanston, IL 60208, United States
| | - Dan T A Eisenberg
- Department of Anthropology, University of Washington, Seattle, United States; Center for Studies in Demography and Ecology, University of Washington, Seattle, United States
| | - Margarita Rzhetskaya
- Division of Endocrinology, Metabolism, and Molecular Medicine, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, United States
| | - M Geoffrey Hayes
- Department of Anthropology, Northwestern University, Evanston, IL 60208, United States; Division of Endocrinology, Metabolism, and Molecular Medicine, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, United States; Center for Genetic Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, United States
| | - Alan B Feranil
- USC Office of Population Studies Foundation and Department of Anthropology, Sociology, and History, College of Arts and Sciences, University of San Carlos, Talamban Cebu City, Philippines
| | - Sonny Agustin Bechayda
- USC Office of Population Studies Foundation and Department of Anthropology, Sociology, and History, College of Arts and Sciences, University of San Carlos, Talamban Cebu City, Philippines
| | - Christopher W Kuzawa
- Department of Anthropology, Northwestern University, Evanston, IL 60208, United States; Institute for Policy Research, Northwestern University, Evanston, IL 60208, United States
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63
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Abstract
AbstractVariation in the quality of parental care has a tremendous impact on a child's social–emotional development. Research investigating the predictors of this variability in human caregiving behavior has mostly focused on learning mechanisms. Evidence is currently accumulating for the complementary underlying role of steroid hormones and neuropeptides. An overview is provided of the hormones and neuropeptides relevant for human caregiving behavior. Then the developmental factors are described that stimulate variability in sensitivity to these hormones and neuropeptides, which may result in variability in the behavioral repertoire of caregiving. The role of genetic variation in neuropeptide and steroid receptors, the role of testosterone and oxytocin during fetal development and parturition, and the impact of experienced caregiving in childhood on functioning of the neuroendocrine stress and oxytocin system are discussed. Besides providing a heuristic framework for further research on the ontogenetic development of human caregiving, a neuroendocrine model is also presented for the intergenerational transmission of caregiving practices. Insight into the underlying biological mechanisms that bring about maladaptive caregiving behavior, such as neglect and insensitive parenting, will hopefully result in more efficient approaches to reduce the high prevalence of such behavior and to minimize the impact on those affected.
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64
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French JA, Taylor JH, Mustoe AC, Cavanaugh J. Neuropeptide diversity and the regulation of social behavior in New World primates. Front Neuroendocrinol 2016; 42:18-39. [PMID: 27020799 PMCID: PMC5030117 DOI: 10.1016/j.yfrne.2016.03.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 02/27/2016] [Accepted: 03/24/2016] [Indexed: 01/09/2023]
Abstract
Oxytocin (OT) and vasopressin (AVP) are important hypothalamic neuropeptides that regulate peripheral physiology, and have emerged as important modulators of brain function, particularly in the social realm. OT structure and the genes that ultimately determine structure are highly conserved among diverse eutherian mammals, but recent discoveries have identified surprising variability in OT and peptide structure in New World monkeys (NWM), with five new OT variants identified to date. This review explores these new findings in light of comparative OT/AVP ligand evolution, documents coevolutionary changes in the oxytocin and vasopressin receptors (OTR and V1aR), and highlights the distribution of neuropeptidergic neurons and receptors in the primate brain. Finally, the behavioral consequences of OT and AVP in regulating NWM sociality are summarized, demonstrating important neuromodulatory effects of these compounds and OT ligand-specific influences in certain social domains.
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Affiliation(s)
- Jeffrey A French
- Program in Neuroscience and Behavior, University of Nebraska at Omaha, Omaha, NE 68182, USA.
| | - Jack H Taylor
- Program in Neuroscience and Behavior, University of Nebraska at Omaha, Omaha, NE 68182, USA
| | - Aaryn C Mustoe
- Program in Neuroscience and Behavior, University of Nebraska at Omaha, Omaha, NE 68182, USA
| | - Jon Cavanaugh
- Program in Neuroscience and Behavior, University of Nebraska at Omaha, Omaha, NE 68182, USA
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Hyer MM, Hunter TJ, Katakam J, Wolz T, Glasper ER. Neurogenesis and anxiety-like behavior in male California mice during the mate's postpartum period. Eur J Neurosci 2016; 43:703-9. [PMID: 26750200 DOI: 10.1111/ejn.13168] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 12/29/2015] [Accepted: 01/04/2016] [Indexed: 10/22/2022]
Abstract
Our understanding of postpartum anxiety (PPA) in fathers is limited, despite the negative consequences of anxiety on the father and child. Offspring contact reduces PPA in mothers; however, parallel investigations in fathers has gone unaddressed. Adult neurogenesis in the dentate gyrus (DG) contributes to anxiety regulation and is altered during the postpartum period, yet the effects of fatherhood on the production, or survival, of newborn cells in the DG, and the role of adult neurogenesis in PPA regulation, have not been examined. Using the biparental California mouse (Peromyscus californicus), we examined the relationships among postnatal day, anxiety-like behavior and adult neurogenesis in fathers. We hypothesized that attenuated anxiety-like behavior and enhanced adult neurogenesis would be observed when father-offspring contact was increased. We observed a reduction in anxiety-like behavior on the elevated plus-maze, but only at PND 16, a time of peak pup retrieval. Fatherhood reduced 1-week survival of newborn cells; however, surviving cells were maintained until 2 weeks postpartum. In contrast, non-fathers experienced a significant reduction in the survival of newborn cells between 1 and 2 weeks postpartum. Fatherhood also increased the numbers of newborn cells that expressed a neuronal phenotype. Collectively, these findings suggest that offspring interaction contributes to reductions in anxiety-like behavior and the maintenance of newborn neurons in the DG of fathers. These data contribute to our knowledge of the postpartum affective state in fathers, findings that may contribute to improved health of both the father and offspring.
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Affiliation(s)
- M M Hyer
- Neuroscience and Cognitive Sciences Program, University of Maryland, College Park, MD, 20742, USA
| | - T J Hunter
- Department of Psychology, University of Maryland, College Park, MD, 20742, USA
| | - J Katakam
- Department of Psychology, University of Maryland, College Park, MD, 20742, USA
| | - T Wolz
- Department of Psychology, University of Maryland, College Park, MD, 20742, USA
| | - E R Glasper
- Neuroscience and Cognitive Sciences Program, University of Maryland, College Park, MD, 20742, USA.,Department of Psychology, University of Maryland, College Park, MD, 20742, USA
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Hrdy SB. Variable postpartum responsiveness among humans and other primates with "cooperative breeding": A comparative and evolutionary perspective. Horm Behav 2016; 77:272-83. [PMID: 26518662 DOI: 10.1016/j.yhbeh.2015.10.016] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 10/21/2015] [Accepted: 10/26/2015] [Indexed: 11/26/2022]
Abstract
This article is part of a Special Issue "Parental Care".Until recently, evolutionists reconstructing mother-infant bonding among human ancestors relied on nonhuman primate models characterized by exclusively maternal care, overlooking the highly variable responsiveness exhibited by mothers in species with obligate reliance on allomaternal care and provisioning. It is now increasingly recognized that apes as large-brained, slow maturing, and nutritionally dependent for so long as early humans were, could not have evolved unless "alloparents" (group members other than genetic parents), in addition to parents, had helped mothers to care for and provision offspring, a rearing system known as "cooperative breeding." Here I review situation-dependent maternal responses ranging from highly possessive to permissive, temporarily distancing, rejecting, or infanticidal, documented for a small subset of cooperatively breeding primates. As in many mammals, primate maternal responsiveness is influenced by physical condition, endocrinological priming, prior experience and local environments (especially related to security). But mothers among primates who evolved as cooperative breeders also appear unusually sensitive to cues of social support. In addition to more "sapient" or rational decision-making, humankind's deep history of cooperative breeding must be considered when trying to understand the extremely variable responsiveness of human mothers.
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Affiliation(s)
- Sarah B Hrdy
- Citrona Farms, 21440 County Road 87, Winters, CA 95694, USA.
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