Global ETD Search

1	No Evidence of an Effect of Resource Necessity and Unpredictability on Cognitive Mechanisms for Detecting Greediness and Stinginess January 2019 (has links) abstract: Resource transfers can confer many adaptive benefits such as specialization, helping genetically related individuals, future compensation, and risk-pooling. Need-based transfers are a risk-pooling mechanism in which partners mitigate unpredictable losses by transferring resources based on need. Need-based transfers are likely to be most useful for resources that are necessary and unpredictable because being unable to reliably obtain essential resources would be devastating. However, need-based transfers make people vulnerable to two types of exploitation: a person can be greedy by asking when not in need and a person with a surplus of resources can be stingy by not giving to someone in need. Previous research suggests that people might have cognitive mechanisms for detecting greediness and stinginess, which would serve to protect against exploitation by cheaters. This study investigated whether resources that are necessary and unpredictable are most likely to trigger greediness and stinginess detection mechanisms. Participants saw four types of rules. One rule could be violated through greedy behavior, another through stingy behavior, another by not paying a debt, and another was a descriptive rule that could be violated by not finding one type of resource near another type of resource. Then, participants saw information about events relating to one of the rules and indicated whether the rule in question could have been violated. Consistent with past research, participants were better at detecting greediness, stinginess, and debts not paid than at detecting violations of a descriptive rule. However, contrary to my predictions, the necessity and unpredictability of resources did not impact people’s ability to detect greediness and stinginess. The lack of support for my hypothesis might be because the benefits of detecting greediness and stinginess might outweigh the costs even for situations in which need-based transfer rules are unlikely to apply, because people might be able to consciously activate their greediness and stinginess mechanisms even for resources that would not naturally trigger them, or because of methodological limitations. / Dissertation/Thesis / Masters Thesis Psychology 2019 Cognitive psychology Social psychology Experimental psychology cheater detection evolution greediness need based transfers resource transfers stinginess
2	The Evolutionary and Ecological Consequences of Partner Variation in the Mutualism between Legumes and Symbiotic Nitrogen Fixing Bacteria Simonsen, Anna 13 August 2013 (has links) A fundamental goal in ecology and evolutionary biology has been to understand how microevolutionary forces affect the origin and maintenance of mutualisms over ecological and evolutionary time scales. Mutualistic partners vary in the reciprocal benefits they provide, yet the role of partner variation on microevolutionary forces that impact the maintenance of mutualisms is unclear. Using the mutualism between legumes and nitrogen fixing symbionts, my dissertation investigated the ecological and evolutionary consequences of variation in partner quality. In the first experiment, I demonstrate how insect herbivory can change the costs and benefits of associating with exploiters, and that some degree of exploitation from non-beneficial rhizobia can reduce insect herbivory, thus removing the fitness advantage of associating purely with beneficial rhizobia. In the second study, I examine how rhizobia genotype modifies competition between hosts grown in kin and non-kin groups. I show that lower fitness in plant kin groups can simply be a by-product of genetic variance in plant size and non-linear relationships between plant size and fitness. I further show that the symbiotic community can change difference in fitness between kin and non-kin groups independent of these by-product effects. In my last chapter, I provide the first empirical evidence that an important mechanism for mutualism stability-- the ability for hosts to preferentially associate with beneficial rhizobia-- is genetically variable and can evolve in response to exploitation. I also show that host preference for beneficial rhizobia can be maintained in legume populations, even in the absence of exploitation. My dissertation provides insight into the potential evolutionary dynamics of stabilizing mechanisms by suggesting that the agents of selection that affect the level of host exploitation can come from biotic factors other than the exploiters themselves. My dissertation has also shown that inclusion of other ecological interactions, such as herbivory, can provide valuable perspective on fitness effects of symbionts on their hosts, and can even change our fundamental assumptions about the effects of exploitation on host fitness, which has formed the backbone of mutualism theory. evolutionary ecology mutualisms legume Rhizobia nitrogen-fixation microbial symbiont exploiter cheater herbivory competition selection context-dependency 0329 0410 0369
3	The Evolutionary and Ecological Consequences of Partner Variation in the Mutualism between Legumes and Symbiotic Nitrogen Fixing Bacteria Simonsen, Anna 13 August 2013 (has links) A fundamental goal in ecology and evolutionary biology has been to understand how microevolutionary forces affect the origin and maintenance of mutualisms over ecological and evolutionary time scales. Mutualistic partners vary in the reciprocal benefits they provide, yet the role of partner variation on microevolutionary forces that impact the maintenance of mutualisms is unclear. Using the mutualism between legumes and nitrogen fixing symbionts, my dissertation investigated the ecological and evolutionary consequences of variation in partner quality. In the first experiment, I demonstrate how insect herbivory can change the costs and benefits of associating with exploiters, and that some degree of exploitation from non-beneficial rhizobia can reduce insect herbivory, thus removing the fitness advantage of associating purely with beneficial rhizobia. In the second study, I examine how rhizobia genotype modifies competition between hosts grown in kin and non-kin groups. I show that lower fitness in plant kin groups can simply be a by-product of genetic variance in plant size and non-linear relationships between plant size and fitness. I further show that the symbiotic community can change difference in fitness between kin and non-kin groups independent of these by-product effects. In my last chapter, I provide the first empirical evidence that an important mechanism for mutualism stability-- the ability for hosts to preferentially associate with beneficial rhizobia-- is genetically variable and can evolve in response to exploitation. I also show that host preference for beneficial rhizobia can be maintained in legume populations, even in the absence of exploitation. My dissertation provides insight into the potential evolutionary dynamics of stabilizing mechanisms by suggesting that the agents of selection that affect the level of host exploitation can come from biotic factors other than the exploiters themselves. My dissertation has also shown that inclusion of other ecological interactions, such as herbivory, can provide valuable perspective on fitness effects of symbionts on their hosts, and can even change our fundamental assumptions about the effects of exploitation on host fitness, which has formed the backbone of mutualism theory. evolutionary ecology mutualisms legume Rhizobia nitrogen-fixation microbial symbiont exploiter cheater herbivory competition selection context-dependency 0329 0410 0369
4	Towards a Flexible Bayesian and Deontic Logic of Testing Descriptive and Prescriptive Rules / Explaining Content Effects in the Wason Selection Task / Zur flexiblen bayesschen und deontischen Logik des Testens deskripitiver und präskriptiver Regeln / Eine Erklärung von Inhaltseffekten in der Wasonschen Wahlaufgabe von Sydow, Momme 04 May 2006 (has links) No description available. 150 Psychologie Mathematics and Computer Science Hypothesentesten Wasonsche Wahlaufgabe deontische Logik Bayessche Logik Bayesianische Modelle wissensbasiertes Lernen kausale Modelle Konditionale Implikation Inhaltseffekte Denken Domänenspezifität Rationalität Induktionsproblem Rabenparadox Synduktion Soziale Verträge Betrüger Erkennung Kooperations Erkennung Kooperation Hypothesis testing Wason selection task deontic logic Bayesian logic conditionals Bayesian models implication knowledge-based learning causal models content effects reasoning domain specificity rationality problem of induction ravens paradox knowledge-based induction synduction social contracts cheater detection social contracts cooperator detection pragmatic reasoning schema theory mental model theory 77.31

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