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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Examining Relations among Early-Life Stress, Deprivation, and Risk-Taking for Primary Resources

Bianchi, JeanMarie. January 2016 (has links)
The following thesis presents the results of a mixed-design study (quasi-experimental and true experimental) testing an integrated model of human risk-taking behavior, defined statistically as a preference for variance in outcomes. The research presented examines the relationships among early-life environmental conditions (i.e., harshness and unpredictability), life-history strategy, and risk-taking behavior for primary resources under various "resource-budget" conditions consisting of deprivation and non-deprivation in two areas: (1) Social-inclusion and (2) caloric "Energy-budget." Two hundred and forty seven (N=247) university students participated in the research. In session one, participants completed multiple questionnaires assessing levels of environmental harshness and unpredictability experienced during development and individual life-history strategy. In session two, participants were pseudo-randomly assigned to experience laboratory induced deprivation or non-deprivation in one of two possible areas: Social-inclusion or caloric "Energy-budget." Following the experimental manipulations, participants played two different behavioral risk-taking tasks: (1) The Wheel Spin Risk Task which required participants to select between a low variance "safe" wheel and a high variance "risky" wheel in an attempt to earn either points or food rewards (depending upon study condition). (2) The Operant Risk Taking Task which required participants to select between a low variance "safe" keyboard key which produced constant rewards and a high variance "risky" keyboard key which produced variable rewards (points or food, depending upon study condition). The results of the multivariate analyses supported main effects only (no moderation) between the characteristics of the early-life environment, life-history strategy, and the experimental manipulations on risk-taking behavior. Specifically, early-life harshness was significantly associated with a faster life-history strategy in participants. Participants with a faster life-history strategy were significantly more likely to select the risky spin wheel on the Wheel Spin Risk Task than were slower life-history strategy participants who were more likely to select the safe spin wheel. Furthermore, participants who experienced the deprivation experimental manipulations behaved more risky on the Operant Risk-Taking Task (for reward amount) than did participants exposed to the non-deprivation manipulations in the study. Interestingly, this effect was domain-general in that deprivation in either Social-inclusion or Energy-budget was associated with risk taking for both social points and for food rewards. The results of this study suggest that life-history strategy is predictive of instrumental risk-taking behavior for reward amount and that deprivation in adaptive areas like Social-inclusion and Energy-budget enhances risk-taking behavior for primary rewards in a domain-general manner as opposed to a domain-specific manner.
12

Rule-Governed Behavior: Investigating a Structural Model of Influences on Adherence to Rules

Gladden, Paul Robert January 2011 (has links)
Behavior-analytic accounts of rule-adherence behavior suggest that rule-governance is a general class of functional (i.e., instrumental) behavior maintained by social consequences (Baum, 2005; Malott & Suarez, 2004; Jacobs et al., in prep.). Evolutionary Life-History (LH) theory suggests that LH strategy may underlie variation in rule-adherence behavior. Based on an integration of these two theories, a theoretical structural model of rule-governance was developed and tested. The structure of this model was used to develop follow-up experiments to test particularly salient links in the model. Consistent with theory, the structural model indicated that slow LH strategy directly and indirectly (through increased moral emotions and increased executive functioning) contributed to strength of rule-governance. Two experiments failed to replicate previously demonstrated effects of executive function depletion or moral identity priming (on moral behavioral outcome measures). Further, self-report measures of slow LH strategy, executive functioning, and rule-governance did not predict prosocial (donating) or rule-defiance (cheating) behavior in laboratory tasks. The limitations of relying solely on either self-report or behavioral tasks of unknown external validity are discussed.
13

Bridging the Gap: Fertility Timing in the United States, Theoretical Vantage Points, Effective Public Policy, and Prevention Design

Tilley, Elizabeth Heidi January 2012 (has links)
The United States has one of the highest teen pregnancy rates among developed countries and ranks third overall in rates of teen pregnancy out of thirty countries in the Organization for Economic Cooperative Development, OECD (UNICEF, 2007). However, as a country we are spending an enormous amount of money on teen pregnancy prevention programs. For example, the Office of Adolescent Health has implemented grant funding opportunities for teen pregnancy prevention programs and provides approximately $105 million to states to design these programs. These programs include personal responsibility education and abstinence only education (http://www.hhs.gov/ash/oah/oah-initiatives/tpp). If we are spending this much on these programs, why do we still have one of the highest teen pregnancy rates among developed countries? Based on what we have learned from current prevention efforts, the goal of this dissertation is two-fold, to introduce alternative theoretical approaches for prevention design and test determinants and protective factors of sexual risk-taking in adolescence. To obtain these goals, this dissertation was written using the three paper option that contains a theoretical paper and two empirical papers that test hypotheses of determinants of sexual risk-taking in adolescence and possible factors that protect youth from engaging in sexual risk-taking, such as school-wide communication and sexual education. The theoretical paper introduces alternative theoretical approaches to not only target individual behavior that may be risky, but also target the contextual constraints in which teens are operating. The empirical papers analyze possible determinants and protective factors for sexual risk-taking in youth.
14

Drivers of variation in the migration and foraging strategies of pelagic seabirds

Clay, Thomas Anthony January 2017 (has links)
The ability to move and forage efficiently plays a major role in determining the fate of individuals, and has important implications for population dynamics and ecosystem functioning. Migration is a particular type of movement strategy, whereby animals may travel remarkable distances in order to take advantage of seasonality in resource availability or to avoid arduous winter conditions; however, this can be at a cost in terms of increased mortality. Indeed, anthropogenic threats in non-breeding areas are a major cause of population declines and a better understanding of non-breeding spatial ecology is required in order to advance both ecological theory and conservation management. The recent development of animal tracking technologies, in particular light-based geolocation, has made it possible to track large-scale and long-term movements; however, there are still gaps in our knowledge, such as the links between migratory and reproductive performance, connectivity among populations and the ontogeny of migration strategies. In this thesis, I utilise multi-species and longitudinal datasets from albatrosses and petrels, some of the most mobile species on Earth, to explore the drivers of variation in movements, habitat use and foraging behaviour, and the implications for life history and conservation. In Chapter 1, I provide an overview of the key topics of this thesis. In Chapter 2, I provide quantitative recommendations of minimum sample sizes needed to track pelagic seabird migrations, using data from 10 species. In Chapter 3, I examine between- and within-population differences in the habitat preferences and distributions of albatrosses, including the relative roles of habitat specialization and intra-specific competition. In Chapter 4, I investigate the year-round movement and foraging strategies of petrels living in nutrient-poor environments. In Chapter 5, I examine potential links between foraging behaviour during the non-breeding season and reproductive senescence. In Chapter 6, I explore the ontogeny of foraging behaviour and foraging site fidelity in young albatrosses, shedding light on their “lost years” at sea. Finally, I conclude with a general discussion summarizing main findings and suggesting future work. Overall, my results highlight the complex relationships among individual traits, the environment, movements and foraging behaviour, and population dynamics across the lifespan of individuals, with implications for the conservation of this highly threatened group of species.
15

Positive Perceptions of Atheists

January 2018 (has links)
abstract: Anti-atheist prejudice is cross-culturally prevalent and marked by intuitive distrust. However, recent research suggests that, when social perceivers know additional relevant information about others (i.e., their reproductive strategies), this information overrides religious information and nonreligious targets are trusted as much as religious targets. That is, perceivers seem to use religious information as a cue to a specific set of behavioral traits, but prioritize direct information about these traits when available. Here, I use this framework to explore the possibility that atheists are viewed positively in certain circumstances. First, atheists might be viewed positively for certain purposes because of their perceived reproductive strategies, even while being trusted less. Second, atheists who are family-oriented do not sacrifice trust, but may still be viewed positively for other traits (i.e., open-mindedness, scientific thinking). Third, given the constraints religion often imposes on behavior, atheists might be trusted more in situations where these constraints interfere with religious people’s inclination to cooperate. I tested these hypotheses using fictitious social media profiles to examine social perception. The study had a 3 (Target Religion: Religious, Nonreligious, or Atheist) × 3 (Target Reproductive Strategy: No Information, Committed, Uncommitted) experimental design (N = 550). Contrary to my predictions, participants did not rate atheists and nonreligious targets as “fast” compared to religious targets. Consistent with predictions, however, atheists and nonreligious individuals were rated significantly higher on perceived open-mindedness and scientific thinking. Finally, atheist and nonreligious targets were trusted more in two of the three trust domains: trust with scientific findings that contradict their worldview and trust with a secret about a friend’s abortion. Further analyses compared patterns of responding for religious and nonreligious individuals, finding evidence for ingroup bias in most perceptions, but not all. Results suggest that perceptions of atheists are complex, but that atheists may, at least sometimes, be viewed favorably. Finally, these results point to the importance of reproductive strategy as a dimension of social perception, as this variable had a clear effect, independent of target religion, on the hypothesized perceptions. / Dissertation/Thesis / Masters Thesis Psychology 2018
16

A Journey through Time and Space: Examining the Influence of Contextual Factors on the Ontogeny of Human Life History Strategies

Cabeza De Baca, Tomás January 2014 (has links)
Researchers must consider the role of context when examining the behavior and characteristics of an individual. An individual must alter development, characteristics, and behavior, to adequately meet the challenges presented within their ecology. The following dissertation presents three manuscripts that examine individual differences while considering the role ecological (spatial) and developmental (temporal) context plays on the individual. Each paper utilizes Life History Theory to examine and to integrate the study findings into a cohesive framework. Life history theory is an evolutionary-developmental theory that focuses on how allocation of bioenergetic and material resources to different developmental facets will have long-term implications for behavior, traits, and health. Each paper collectively highlights key contextual factors throughout the lifespan and seeks to understand how life history strategies emerge. Study I examined the role mother's behavior had on the development of the child unpredictability schema (i.e., worldview where children view their environment and others as unreliable). The study included 65 children and their mothers. Results revealed that child unpredictability schema was predicted by mother's mating and parental effort. A quadratic effect was also found, whereby child unpredictability schema became constant at lower levels of parental effort. Study II utilized retrospective reports of childhood parental effort from extended kin family, positive emotional environment, and traditional social values from a sample of 200 Mexican and Costa Rican college students. High levels of childcare assistance from patrilineal and matrilineal kin were associated with more positive family environment, and the association was partially mediated between kin care and slow life history. Positive associations were also found between matrilineal kin childcare and traditional Latin social values. Study III utilized a nationally-representative, all-female sample to test whether higher reproductive effort increases physical/mental deterioration in women. Results reveal that reproductive effort and illness were mediated by both antioxidant defenses and inflammation. The results of the three studies broadly support hypotheses generated from Life History Theory. Contextual factors during key developmental stages have an impact on how an individual will allocate time and bioenergetic resources - thus contributing to specific behavioral life history strategies.
17

A Life-History Model of Human Fitness Indicators

Sefcek, Jon Adam January 2007 (has links)
Recent adaptationist accounts of human mental and physical health have reinvigorated the debate over the evolution of human intelligence. In the tradition of strong inference the current study was developed to determine which hypothesis; Rushton’s (2000) differential K theory, or Miller’s (2000a) fitness indicator model (F), better accounts for general intelligence ('g') in an undergraduate university population (N = 194). Due to the lengthy administration time of the test materials a newly developed 18-item short form of the Ravens Advanced Progressive Matrices (APM-18; Sefcek, Miller, & Figueredo, 2007) was used. There was a significant positive relationship between K and F (r = .31, p < .001), however no significant relationships were found between 'g' and either K or F (for each, r = -.06, p ≥ .05). While contrary to both hypotheses, these results may be explained in relation to antagonistic pleiotropy and a potential failure to derive within species comparisons directly from between species comparisons.
18

Food Insecurity and Age of Menarche: Using a Biocultural Approach and Life History Theory to Assess Risks of Food Insecurity among Girls in Tampa Bay, FL

Burris, Mecca 21 March 2018 (has links)
Using life-history theory within a biocultural perspective, this research explores whether household food insecurity correlates with early or delayed menarche among adolescent females in Tampa Bay, Florida. Early onset of puberty and menstruation is connected with numerous health consequences including growth stunting, obesity, type-2 diabetes, adult-onset asthma, reproductive cancers, increased risk for depression, behavioral problems, and early sexual activity which increases the risk for STIs and ovarian cancer. Early menarche also seems to disproportionally impact disadvantaged and minority groups. While there are many known factors that influence age at menarche (e.g.: genetics, diet), little is understood regarding the effect of food insecurity on menstrual timing. When considering food insecurity as an environmental adversity, long-term exposure may result in biological trade-offs within growth and development. Using a mixed-methods approach, 40 girls and 36 parents or guardians from Pinellas, Hillsborough, and Manatee counties participated in household dyadic interviews that included the assessment of household food security, girls’ dietary analysis, and anthropometry. Using quantitative analyses, the associations of diet, food security, and body size/composition to menarche were evaluated. A Cox hazards model and regression further analyzed the association of food insecurity and the timing of menarche. The research concludes that adolescents and their families are vulnerable to food insecurity for both biological and social reasons. Qualitative results examine the prevalence, experiences, and perpetrators of food insecurity, as well as strategies used by families to mitigate food insecurity. Food insecurity in this study refers to the inconsistent or limited access to adequate amounts of safe and nutritious foods to sustain health and wellbeing. Food insecurity does not necessarily result in hunger. Once can have access to enough calories and not feel hungry but may still be food insecure if their access does not include enough high-quality, nutritious foods. Quantitative analyses showed that iliac height, waist-hip ratio, snack consumption, and household food insecurity is associated with age at menarche among this sample. Spearman’s Rho confirms that height, leg length (p = 0.032, rs = 0.407), and snack consumption (p = 0.042, rs = 0.464) significantly positively correlate with age at menarche. Waist-hip ratio significantly negatively correlates with age at menarche (p = 0.032, rs = -0.518). Cox Hazard Regression analysis interprets that for every one unit increase in household food security survey score, the risk of experiencing menarche increases by 25% (p = 0.023, OR = 1.25). However, when adding leg length, waist-hip ratio, and snack consumption to the Cox Hazard Regression equation, no variables significantly predict menarche. These findings provide a better understanding of the biocultural influences within the timing of menarche. The research provides new insights and further stresses the importance of improving food assistance programs for adolescents and families with older children.
19

An Affordance Management, Life History Approach to Perceptions of Criminal Behavior

January 2017 (has links)
abstract: Why do social perceivers use race to infer a target's propensity for criminal behavior and likelihood of re-offense? Life history theory proposes that the harshness and unpredictability of one's environment shapes individuals' behavior, with harsh and unpredictable ("desperate") ecologies inducing "fast" life history strategies (characterized by present-focused behaviors), and resource-sufficient and stable ("hopeful") ecologies inducing "slow" life history strategies (characterized by future-focused behaviors). Social perceivers have an implicit understanding of the ways in which ecology shapes behavior, and use cues to ecology to infer a target's likely life history strategy. Additionally, because race is confounded with ecology in the United States, American perceivers use race as a heuristic cue to ecology, stereotyping Black individuals as possessing faster life history strategies than White individuals. In the current project, I proposed that many race stereotypes about propensity for criminality and recidivism actually reflect inferences of life history strategy, and thus track beliefs about the behavioral effects of ecology, rather than race. In a series of three studies, I explored the relationship between ecology, race, and perceptions of criminal behavior. Participants in each experiment were recruited through an online marketplace. Findings indicated that (1) stereotypes regarding likelihood to engage in specific crimes were largely driven by beliefs about the presumed ecology of the offender, rather than the offender's race, such that Black and White targets from desperate (and hopeful) ecologies were stereotyped as similarly likely (or unlikely) to commit a variety of crimes; (2) lay beliefs about recidivism predictors likewise reflected inferences of life history strategy, and thus also tracked ecology rather than race; (3) when evaluating whether to release a specific offender on parole, participants placed greater importance on ecology information as compared to race information in a point allocation task, and prioritized ecology information over race information in a ranking task. Taken together, these findings suggest that beliefs about criminality and recidivism may not be driven by race, per se, but instead reflect inferences of how one's ecology shapes behavior. Implications of these findings for understanding and reducing racial bias in the criminal justice system are discussed. / Dissertation/Thesis / Doctoral Dissertation Psychology 2017
20

Grandmotherhood in Ukraine: Behavioral Variation and Evolutionary Implications

Shreyer, Sofiya 18 December 2020 (has links)
Grandmothers are known to increase the health and well-being of their grandchildren in many different populations. However, grandmothers may vary in their contributions based on their relatedness to their grandchildren. In some populations, maternal grandmothers decrease the risk of mortality and increase the health of their grandchildren more than paternal grandmothers. Grandmaternal influence also sometimes varies based on the gender of the grandchild. The behavioral mechanisms of grandmaternal investment are not well understood and have not been explored in the heavily intergenerational context of Eastern Europe. This study examines the behavioral variation of sixty-two Ukrainian grandmothers through interviews and a semi-structured questionnaire. I test whether maternal and paternal grandmothers differ in face-to-face contact with their grandchildren and whether the gender of the grandchild influences the frequency of face-to-face contact. Additionally, I examine qualitative responses from grandmothers on various aspects of childcare to determine whether maternal and paternal grandmothers have different childcare strategies and experience grandmotherhood in different ways. I found that maternal grandmothers have significantly more face-to-face time with their grandchildren (173.8 days out of the year as compared to 87.5 for paternal grandmothers, p

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