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- Genre: Academic theses
Description
Social insect colonies exhibit striking diversity in social organization. Included in this overwhelming variation in structure are differences in colony queen number. The number of queens per colony varies both intra- and interspecifically and has major impacts on the social dynamics of a colony and the fitness of its members. To understand the evolutionary transition from single to multi-queen colonies, I examined a species which exhibits variation both in mode of colony founding and in the queen number of mature colonies. The California harvester ant Pogonomyrmex californicus exhibits both variation in the number of queens that begin a colony (metrosis) and in the number of queens in adult colonies (gyny). Throughout most of its range, colonies begin with one queen (haplometrosis) but in some populations multiple queens cooperate to initiate colonies (pleometrosis). I present results that confirm co-foundresses are unrelated. I also map the geographic occurrence of pleometrotic populations and show that the phenomenon appears to be localized in southern California and Northern Baja California. Additionally, I provide genetic evidence that pleometrosis leads to primary polygyny (polygyny developing from pleometrosis) a phenomenon which has received little attention and is poorly understood. Phylogenetic and haplotype analyses utilizing mitochondrial markers reveal that populations of both behavioral types in California are closely related and have low mitochondrial diversity. Nuclear markers however, indicate strong barriers to gene flow between focal populations. I also show that intrinsic differences in queen behavior lead to the two types of populations observed. Even though populations exhibit strong tendencies on average toward haplo- or pleometrosis, within population variation exists among queens for behaviors relevant to metrosis and gyny. These results are important in understanding the dynamics and evolutionary history of a distinct form of cooperation among unrelated social insects. They also help to understand the dynamics of intraspecific variation and the conflicting forces of local adaptation and gene flow.
ContributorsOverson, Rick P (Author) / Gadau, Jürgen (Thesis advisor) / Fewell, Jennifer H (Committee member) / Hölldobler, Bert (Committee member) / Johnson, Robert A. (Committee member) / Liebig, Jürgen (Committee member) / Arizona State University (Publisher)
Created2011
Description
As the world's resources face increasing pressure from a growing population, it is critical that psychologists understand the motivational processes that lead to cooperation or defection in the context of social dilemmas. Research has uncovered several key strategies for encouraging maintenance of these resources, however, one area that remains understudied is the effect various emotions may have on cooperation. Furthermore, it is important to consider the specific type of desired behavior: reduction of consumption of a shared resource, or increased contribution to a shared resource. The current study takes a step in this direction, examining the effects of two self-conscious emotions, guilt and pride, on behavior in two different kinds of social dilemmas. Guilt, a prosocial emotion that has been described as a "behavioral interrupt mechanism," is predicted to increase cooperation in both a social trap game and a public goods dilemma game. However, its effects should be strongest in the social trap game, in which the desired behavior is reduced consumption. Pride, an emotion that is conceptually related to the constructs of status and power, is predicted to motivate action in both domains, by increasing both consumption in the social trap game and contribution in the public goods dilemma game. Results partially support these predictions: Whereas guilt and pride both had the predicted effects on consumption in the social trap game, neither had a significant effect on contribution in the public goods dilemma game. Individual differences are examined, as are the results of a Game Feedback Sheet, which yielded insight as to how participants understood the rules of the games, and why they chose the strategies they did. Results support the idea that emotions represent a potentially fruitful avenue of research in social dilemma cooperation, and possible future directions for this research are discussed.
ContributorsNeufeld, Samantha L (Author) / Shiota, Michelle N. (Thesis advisor) / Kenrick, Douglas T. (Committee member) / Ledlow, Susan E (Committee member) / Saks, Michael J. (Committee member) / Arizona State University (Publisher)
Created2012
Description
The broaden-and-build theory of positive emotion suggests that positive emotions should broaden thought and behavior repertoires in order to develop lasting resources. In the social domain, this means deploying a variety of affiliative strategies in order to build cooperative relationships. A functionalist perspective on positive emotion suggests that different positive emotions should have distinct effects on these affiliative mechanisms. This study elicited awe, amusement, pride or a neutral control in pairs of same sex strangers. They then completed an open-ended "getting to know you" conversation, which were recorded and coded for affiliative behaviors—smiling, laughter, mimicry, and asking questions. After, they rated their perception of the other as complex and how much they liked each other. Then they played the prisoner's dilemma game. Results indicate that there was a significant mediated effect such that being in the pride condition predicted greater smiling, and smiling predicted cooperation on the prisoner's dilemma. This was true both when an individual's own smiling was predicting their cooperative behavior and when their partner's smiling was predicting their cooperative behavior. However, these effects were only seen in female dyads, not male dyads. There was also a significant mediated effect such that pride led women to ask more questions, which led partners to like each other more. Additionally, awe led to greater mimicry in men, which in turn led to greater cooperation. In women, awe led to greater perception of the other as complex. Overall, these results indicate that there are broaden and build effects of positive emotions, but these are specific to both the emotion and the sex of the interaction members. This is also the first study to demonstrate both an actor and a partner effect of smiling on cooperation in a prisoner’s dilemma. An important area for further inquiry will be the interaction of emotion and sex in predicting social behavior. While sex differences in responding to threats have been characterized by the “tend and befriend” versus “fight or flight” action patterns, a similar approach may also need to be developed for sex differences in response to opportunities.
ContributorsDanvers, Alexander (Author) / Shiota, Michelle N. (Thesis advisor) / Neuberg, Steven L. (Committee member) / Kwan, Virginia S.Y. (Committee member) / Arizona State University (Publisher)
Created2015
Description
An important component of insect social structure is the number of queens that cohabitate in a colony. Queen number is highly variable between and within species. It can begin at colony initiation when often unrelated queens form cooperative social groups, a strategy known as primary polygyny. The non-kin cooperative groups formed by primary polygyny have profound effects on the social dynamics and inclusive fitness benefits within a colony. Despite this, the evolution of non-kin queen cooperation has been relatively overlooked in considerations of the evolution of cooperative sociality. To date, studies examining the costs and benefits of primary polygyny have focused primarily on the advantages of multiple queens during colony founding and early growth, but the impact of their presence extends to colony maturity and reproduction.
In this dissertation, I evaluate the ecological drivers and fitness consequences of non-kin queen cooperation, by comparing the reproduction of mature single-queen versus polygynous harvester ant (Pogonomyrmex californicus) colonies in the field. I captured and quantified the total number and biomass of reproductives across multiple mating seasons, comparing between populations that vary in the proportion of single queen versus polygynous colonies, to assess the fitness outcomes of queen cooperation. Colonies in a mainly polygynous site had lower reproductive investment than those in sites with predominantly single-queen colonies. The site dominated by polygyny had higher colony density and displayed evidence of resource limitation, pressures that may drive the evolution of queen cooperation.
I also used microsatellite markers to examine how polygynous queens share worker and reproductive production with nest-mate queens. The majority of queens fairly contribute to worker production and equally share reproductive output. However, there is a low frequency of queens that under-produce workers and over-produce reproductive offspring. This suggests that cheating by reproducing queens is possible, but uncommon. Competitive pressure from neighboring colonies could reduce the success of colonies that contain cheaters and maintain a low frequency of this phenotype in the population.
In this dissertation, I evaluate the ecological drivers and fitness consequences of non-kin queen cooperation, by comparing the reproduction of mature single-queen versus polygynous harvester ant (Pogonomyrmex californicus) colonies in the field. I captured and quantified the total number and biomass of reproductives across multiple mating seasons, comparing between populations that vary in the proportion of single queen versus polygynous colonies, to assess the fitness outcomes of queen cooperation. Colonies in a mainly polygynous site had lower reproductive investment than those in sites with predominantly single-queen colonies. The site dominated by polygyny had higher colony density and displayed evidence of resource limitation, pressures that may drive the evolution of queen cooperation.
I also used microsatellite markers to examine how polygynous queens share worker and reproductive production with nest-mate queens. The majority of queens fairly contribute to worker production and equally share reproductive output. However, there is a low frequency of queens that under-produce workers and over-produce reproductive offspring. This suggests that cheating by reproducing queens is possible, but uncommon. Competitive pressure from neighboring colonies could reduce the success of colonies that contain cheaters and maintain a low frequency of this phenotype in the population.
ContributorsHaney, Brian R (Author) / Fewell, Jennifer H (Thesis advisor) / Cole, Blaine J. (Committee member) / Gadau, Juergen (Committee member) / Hoelldobler, Bert (Committee member) / Rutowski, Ron L (Committee member) / Arizona State University (Publisher)
Created2017
Description
Friendships make us happy, keep us healthy, and can even facilitate our reproductive fitness. But most friendships are not forever—even when we want them to be. How do people maintain valued friendships? I propose that “friendship jealousy” arises when people perceive others as posing threats to valued friendships, and that this response can function to prevent friendship loss and friend defection. In preliminary experiments, I tested predictions derived from this functional view. As predicted, I found, first, that friendship jealousy is calibrated to friend value. Second, friendship jealousy predicts intentions to “friend guard” (i.e., engage in behavior to protect the friendship). Third, friendship jealousy has sex-differentiated features, which are consistent with sex differences in friendship structures and ancestral friendship functions. The present work pits against one another intuitive and functional predictions as to what drives friendship jealousy. Although intuition might lead one to expect greater jealousy when a friend spends more time with a new person, a functional view suggests greater jealousy when that new person threatens to fulfill the same function for one’s friend that one is currently fulfilling (i.e., to “replace” him/her). Preliminary studies revealed that greater friendship jealousy is evoked when friends form new same-sex friendships (which presumably pose greater replacement threat, but lesser time threat) versus new romantic relationships (which presumably pose lesser replacement threat, but greater time threat). The focal experiment explicitly and experimentally manipulates a version of “replacement threat” (whether the best friend “chooses” the new friend over you) and “time threat” (how much time the best friend spends with the new friend). In line with functional predictions, the amount of time the best friend spends with a new friend drives friendship jealousy—but only when direct information about replacement threat is unavailable. Regardless of the time threat posed, participants report high friendship jealousy when replacement threat is high, and low friendship jealousy when replacement threat is low. Results imply that friendship jealousy is calibrated to replacement threat (over time threat). Overall, findings suggest that friendship jealousy might be a functional response aimed at facilitating friendship maintenance.
ContributorsKrems, Jaimie Arona (Author) / Kenrick, Douglas T. (Thesis advisor) / Neuberg, Steven L. (Thesis advisor) / Aktipis, Athena (Committee member) / Ha, Phuong Thao (Committee member) / Arizona State University (Publisher)
Created2018
Description
In Latin America food insecurity is still prevailing in those regions where extreme poverty and political instability are common. Tseltal communities are experiencing changes due to religious conversions and the incursion of external political institutions. These changes have diminished the importance of traditional reciprocal and redistributive institutions that historically have been essential for personal and community survival. This dissertation investigated the impact that variations on governance systems and presence of reciprocal and distributional exchanges have on the food security status of communities. Qualitative data collected in four communities through 117 free lists and 117 semi-structured interviews was used to elaborate six scales that correspond to the traditional and civic authority system and to inter-community and intra-community reciprocity and redistribution. I explore the relationship that the scores of four communities on those scales have on the food security status of their inhabitants based on their results on the National Health and Nutrition Survey 2012. Findings from this study suggest that in marginalized communities that many scientists would described as experiencing market failure, participation in inter-community reciprocal, intra-community reciprocal and intra-community redistribution are better predictors of food security than enrollment in food security programs. Additionally, communities that participated the most in these non-market mechanisms have stronger traditional institutions. In contrast, communities that participated more in inter-community redistribution scored higher on the civic authority scale, are enrolled in more food aid programs, but are less food secure.
ContributorsDe La Torre Pacheco, Sindy Yaneth (Author) / Janssen, Marco (Thesis advisor) / Eakin, Hallie (Committee member) / BurnSilver, Shauna (Committee member) / Arizona State University (Publisher)
Created2015
Description
Exclusivity and duration of breastfeeding and the provision of human milk in the United States is suboptimal. In the absence of adequate banked donor human milk for distribution to all infants in need, many families choose to engage in the practice of Private Arrangement Milk Sharing (PAMS), partially facilitated through social media, to procure human milk for their infants. Evidence regarding the participant and infant characteristics and risk abatement practices is incomplete. This dissertation describes and explores the characteristics of recipient participants and infants, family constellation, donor screening practices, and related risk abatement strategies. Data was collected via on-line survey as a sub-group of a larger data set including donor participants and international participants. Binary logistic regression modeling of factors that contribute to consistent screening and risk abatement practices and important antecedents to engaging in PAMS was conducted. Results are contextualized within a tailored socioecological framework of factors affecting infant feeding practices. Tailoring was accomplished via qualitative descriptive analysis of participant responses applied to an existing breastfeeding framework. Participants in this sample were predominantly white, married, with a mean age of 32.9 years, with at least some college education and above median income. Risk abatement and screening practices were influenced by support of a healthcare provider during decision-making, college education, infant age and health status, having lactation support, birth type and birth attendant, and the duration and sources sought for learning about milk sharing.
ContributorsBond, Angela Bowen (Author) / Reifsnider, Elizabeth G. (Thesis advisor) / Keller, Colleen (Committee member) / Todd, Michael (Committee member) / Arizona State University (Publisher)
Created2016
Description
A key factor in the success of social animals is their organization of work. Mathematical models have been instrumental in unraveling how simple, individual-based rules can generate collective patterns via self-organization. However, existing models offer limited insights into how these patterns are shaped by behavioral differences within groups, in part because they focus on analyzing specific rules rather than general mechanisms that can explain behavior at the individual-level. My work argues for a more principled approach that focuses on the question of how individuals make decisions in costly environments.
In Chapters 2 and 3, I demonstrate how this approach provides novel insights into factors that shape the flexibility and robustness of task organization in harvester ant colonies (Pogonomyrmex barbatus). My results show that the degree to which colonies can respond to work in fluctuating environments depends on how individuals weigh the costs of activity and update their behavior in response to social information. In Chapter 4, I introduce a mathematical framework to study the emergence of collective organization in heterogenous groups. My approach, which is based on the theory of multi-agent systems, focuses on myopic agents whose behavior emerges out of an independent valuation of alternative choices in a given work environment. The product of this dynamic is an equilibrium organization in which agents perform different tasks (or abstain from work) with an analytically defined set of threshold probabilities. The framework is minimally developed, but can be extended to include other factors known to affect task decisions including individual experience and social facilitation. This research contributes a novel approach to developing (and analyzing) models of task organization that can be applied in a broader range of contexts where animals cooperate.
In Chapters 2 and 3, I demonstrate how this approach provides novel insights into factors that shape the flexibility and robustness of task organization in harvester ant colonies (Pogonomyrmex barbatus). My results show that the degree to which colonies can respond to work in fluctuating environments depends on how individuals weigh the costs of activity and update their behavior in response to social information. In Chapter 4, I introduce a mathematical framework to study the emergence of collective organization in heterogenous groups. My approach, which is based on the theory of multi-agent systems, focuses on myopic agents whose behavior emerges out of an independent valuation of alternative choices in a given work environment. The product of this dynamic is an equilibrium organization in which agents perform different tasks (or abstain from work) with an analytically defined set of threshold probabilities. The framework is minimally developed, but can be extended to include other factors known to affect task decisions including individual experience and social facilitation. This research contributes a novel approach to developing (and analyzing) models of task organization that can be applied in a broader range of contexts where animals cooperate.
ContributorsUdiani, Oyita (Author) / Kang, Yun (Thesis advisor) / Fewell, Jennifer H (Thesis advisor) / Janssen, Marcus A (Committee member) / Castillo-Chavez, Carlos (Committee member) / Arizona State University (Publisher)
Created2016
Description
Humans cooperate at levels unseen in other species. Identifying the adaptive mechanisms driving this unusual behavior, as well as how these mechanisms interact to create complex cooperative patterns, remains an open question in anthropology. One impediment to such investigations is that complete, long-term datasets of human cooperative behaviors in small-scale societies are hard to come by; such field research is often hindered both by humans' long lifespans and by the difficulties of collecting data in remote societies. In this study, I attempted to overcome these methodological challenges by simulating individual human cooperative behaviors in a small-scale population. Using an agent-based model tuned to population-level measurements from a real-life marine subsistence population in the southern Philippines, I generated dynamic daily cooperative behaviors in a hypothetical subsistence population over a period of 1500 years and 42 overlapping generations. Preliminary findings from the model suggest that, while the agent-based model broadly captured a number of characteristic population-level patterns in the subsistence population, it did not fully replicate nuances of the population's observed cooperative behaviors. In particular, statistical models of the simulated data identified reciprocity-based and need-based cooperative behaviors but did not detect kinship-motivated cooperation, despite the fact that kin cooperation traits evolved positively and reciprocity cooperation traits evolved negatively over time in the agent population. It is possible that this discrepancy reflects a complex interaction between kinship and reciprocity in the agent-based model. On the other hand, it may also suggest that these types of statistical models, which are frequently utilized in human cooperation studies in the anthropological literature, do not reliably discriminate between kin-based and reciprocity-based cooperation mechanisms when both exist in a population. Even so, the completeness of the simulated data enabled use of more complex statistical methodologies which were able to disentangle the relative effects of cooperative mechanisms operating at different decision levels. By addressing remaining pattern-matching issues, future iterations of the agent-based model may prove to be a useful tool for validating empirical research and investigating novel hypotheses about the evolution and maintenance of cooperative behaviors in human populations.
ContributorsPhelps, Julia R. (Author) / Reiser, Mark (Thesis advisor) / Saul, Steven (Thesis advisor) / Morgan, Thomas (Committee member) / Arizona State University (Publisher)
Created2023
Description
Previous work suggests that lower-income individuals are more likely to engage in mutual aid as a means to manage risk, giving rise to a psychology that is other-oriented, including an empathetic disposition and a proclivity to help people in need. While no study has directly investigated whether helping in times of need increases dispositional empathic concern over time, this assumption is deep-seated among social psychologists. Employing a two-year longitudinal survey of US adults (N = 915), I show that people who experience more needs report helping others when in need a greater number of times, in turn leading to a small but positive increase in their empathetic disposition. This study also identifies the types of needs that elicit empathic concern (i.e., those that arise from unpredictable sources of risk), and shows why cultivating an empathetic disposition is likely to pay off in the long run: those who provide help are more likely to receive help during future times of need. Moreover, this study identifies the types of targets for whom providing help might cultivate an empathetic disposition: those with whom people are likely to share lower interdependence. While previous theoretical frameworks posit that empathic concern selectively directs investment towards interdependent others, providing help to non-interdependent targets might allow people to build positive interdependence with prospective risk pooling partners. Cultivating an empathetic disposition and building interdependence with prospective risk pooling partners can allow people to manage needs that arise from unpredictable sources of risk.
ContributorsGuevara Beltran, Diego (Author) / Aktipis, Athena (Thesis advisor) / Hruschka, Daniel (Committee member) / Kenrick, Douglas (Committee member) / Shiota, Michelle (Committee member) / Arizona State University (Publisher)
Created2023