![]() ![]() The pathways outlined go beyond those discussed in Ostner & Schulke (2018) and Cords & Thompson (2017). Unlike previous reviews, I focus on delineating pathways by which social ties can influence fitness. ![]() Similar to previous reviews of ‘friendship’ in primates (Bergman, 2010 Massen et al., 2010 Seyfarth & Cheney, 2012), I discuss the quantification and function of social ties primarily among same-sex partners. I focus on ties characterized by affiliation, spatial association, and/or cooperation and also on ties that are not directly related to reproduction (e.g., monogamous pairs) but that may occur between kin. My goal in this review is to outline hypotheses on how social ties influence fitness that can either continue or begin to be evaluated by future research. This review focuses on evidence of how social ties influence individual fitness in non-human primates (hereafter primates), with relevant evidence drawn from studies of humans and several non-primate animals. Although long-term research on non-human animals has yet to similarly control for initial health status, it appears well warranted to follow up on correlations between social ties and fitness in non-human primates to understand how ties influence fitness. Health status and related processes like senescence do play a role in social behaviour and attraction between partners (e.g., Roelfs et al., 2011 Almeling et al., 2016), yet these human studies substantiate the independent effects of social ties on health and fitness outcomes. Today, several prospective studies in human biomedical research have controlled for initial health status, revealing that the relationships between social ties and fitness outcomes, like mortality and disease progression, hold regardless of initial health (Holt-Lunstad et al., 2010 Shor & Roelfs, 2015). Namely, better general health and vitality could motivate individuals to be more social, and also make individuals more attractive as social partners (Uchino, 2004). One common criticism of the assertion that social ties increase individual fitness is that such a causal relationship, if present, is actually reversed. This is, in part, because the length and resolution of research projects, particularly on long-lived animals, are not always sufficient to understand the precise pathways by which long-term fitness outcomes come about. Despite the recent proliferation of findings that ‘social ties matter’, the mechanisms by which ties influence fitness are not altogether clear. Studies of several group-living mammals, including primates (Silk et al., 2003, 2009, 2010b Gilby et al., 2013 McFarland & Majolo, 2013 Archie et al., 2014 McFarland et al., 2015 Lehmann et al., 2016 Kalbitzer et al., 2017 McFarland et al., 2017 Thompson & Cords, 2018), rodents (Weidt et al., 2008 Yee et al., 2008), cetaceans (Foster et al., 2012 Stanton & Mann, 2012) and ungulates (Cameron et al., 2009 Vander Wal et al., 2014 Nuñez et al., 2015) have revealed that maintaining affiliative and cooperative ties, both among same and opposite sex partners, corresponds with increased individual fitness, or increased survival and reproductive success. In recent decades, research has focused on examining the adaptive benefits of differentiated, cooperative and affiliative social ties in animals, beyond the general benefits of social living (Lin & Michener, 1972 Silk, 2007). With the advance of theoretical and methodological approaches to evaluate the costs and benefits of social ties, and monitor them at multi-generational field sites, primate behavioural ecologists are poised to test several of these hypotheses. Hypotheses for further evaluation include (1) fitness increases sociality, not vice versa (2) early life experience influences both ties and fitness, (3) ties are actually costly (4) short term costs of ties are outweighed by long term benefits. Pathways include communal care group level cooperation for resources monopolizing resources within groups attaining social status reducing risk and allostatic load and developing behavioural competence. I outline fitness-relevant measures of social ties and 6 potential pathways from ties to fitness. This review is aimed to facilitate the formulation and testing of hypotheses in this area on non-human primates. Many studies highlight the correlation between social ties and fitness, yet often cannot reveal how ties influence fitness. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |