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.

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.

Evolutionary psychology explains and predicts human behaviour based on its adaptive value. Some apparently non-adaptive behaviours such as humans’ devotion to music can be explained by sexual selection of costly signals, since it takes time and effort to learn to play an instrument well. Here, participants rated pictures of persons of the opposite sex that were said to play a piece of music that was heard while watching each picture. The music performances were either of low, medium, or high level of skill, and a better performance was predicted to lead to higher ratings of partner attractiveness because it is more costly. No effect of the music was found, except that women rated men as less desirable for a long-term relationships when the skill level was high than when it was medium. / Evolutionspsykologiska teorier förklarar och predicerar mänskligt beteende utifrån dess adaptiva värde. Vissa uppenbart icke-adaptiva beteenden, som människans hängivenhet till musik, kan förklaras som sexuell selektion av kostsamma signaler, eftersom det kräver tid och möda att lära sig bemästra ett instrument. Deltagare fick skatta bilder på personer av motsatt kön som påstods spela det musikstycke som hördes medan man tittade på varje bild. Musikutförandet var antingen av låg, medel, eller hög skicklighet, och ett bättre utförande förväntades ge högre skattningar av partnerattraktivitet eftersom det är mer kostsamt. Ingen effekt av musiken förelåg, förutom att kvinnorna skattade män som mindre attraktiva för ett längre förhållande när skicklighetsnivån var hög jämfört med när den var medelhög.

This dissertation project investigated fluctuations in estradiol and testosterone across the human menstrual cycle. During the part of the cycle when women are most fertile, women show stronger preferences for men with more masculine faces, and these preference changes may be related to changes in hormone levels during ovulation. The present study investigated preferences changes among women for higher testosterone men over the menstrual cycle as estradiol and testosterone in those women fluctuated. 32 women participated in this 5-week long study tracking their estradiol and testosterone levels and preferences for masculine men. Women with higher levels of estradiol preferred men who had higher levels of testosterone than women who had lower levels of estradiol. During ovulation, women were more like to find high testosterone men more attractive than other parts of the menstrual cycle. In addition to ratings of men, several other psychological tests were administered and examined for changes as a function of state and trait levels of hormones.

Despite most educated people now accepting Darwinian explanations for human physical evolution, many of these same people remain reluctant to accept similar accounts of human behavioural or cognitive evolution. Leftists in particular often assume that our evolutionary history now has little bearing on modern human social behaviour, and that cultural processes have taken over from the biological imperatives at work elsewhere in nature. The leftist view of human nature still largely reflects that of Karl Marx, who believed that our nature is moulded solely by prevailing social and cultural conditions, and that, moreover, our nature can be completely changed by totally changing society. Ethical philosopher Peter Singer challenges this leftist view, arguing that the left must replace its non-Darwinian view of an infinitely malleable human nature with the more accurate scientific account now made possible by modern Darwinian evolutionary science. Darwinism, Singer suggests, could then be used as a source of new ideas and new approaches that could revive and revitalise the egalitarian left. This thesis defends and develops Singer’s arguments for a Darwinian left. It shows that much modern leftist opposition to evolutionary theory is misguided, and that Darwinism does not necessarily have the egregious political implications so often assumed by the egalitarian left – even in such controversial areas as possible ‘biological’ differences between the sexes or between different human populations.

Thesis (Ph.D.)--University of Hawaii at Manoa, 2008. / In recent years, more studies are exploring how contextual factors may influence mate preferences. Based on social learning theory, power, attitudes towards egalitarian gender roles, and type of mating were expected to influence women's romantic preferences for physical attractiveness and for resources. An online questionnaire was administered to a community sample and data analyses were employed using structural equation modeling (SEM) and multivariate analyses of variance (MANOVA). Results showed that, as women's power increased, women showed increased preferences for physical attractiveness and sexiness in potential short-term mates and increased preference for intelligence in potential long-term mates. Power and attitudes were also found to be significant in predicting women's preferences for physical attractiveness relative to potential earning capacity in both short-term and long-term mating conditions. / Includes bibliographical references (leaves 85-92). / Also available by subscription via World Wide Web / 92 leaves, bound 29 cm

Thesis (M.A.)--Ohio University, March, 2010. / Title from PDF t.p. Includes bibliographical references.

Thesis (M.A.)--Miami University, Dept. of Psychology, 2007. / Title from first page of PDF document. Includes bibliographical references (p. 21-24).

In the following thesis I examine the possible evolutionary significance of behavioural differences associated with liberal and conservative ideological orientations. In investigating the evolutionary significance of these two orientations I have two primary research questions. First, how do liberal and conservative oriented individuals differ in their responses to the same socio-environmental stimuli? Second, do differences in their responses to socio-environmental stimuli represent alternative behavioural strategies for social interaction, specifically adaptive strategies to maximize returns from social interactions? To answer these research questions I evaluate how trust and cooperation among liberal and conservative oriented individuals are affected by conditions of social change and inequality. Previous research finds that attitudes and behaviours consistent with the tolerance or intolerance of social change and inequality are strong predictors of ideological orientation across a liberal-conservative scale. Based on a synthesis of behavioural research I construct two theoretical frameworks to account for the adaptive utility associated with a sensitivity to social change and inequality; 1) The Group Reciprocity Hypothesis, and 2) The Social Risk Hypothesis. I test these frameworks using an experimental research design. I predict that, if liberal and conservative orientations are reflective of alternative adaptive strategies to maximize returns from social interaction, then the willingness of liberal and conservative individuals to participate in a social interaction should be differentially affected by conditions related to social change and inequality.

abstract: Pro-environmental goals often pit immediate self-interest against future communal interest. Consequently, the motivation to behave in pro-environmental ways can be particularly difficult to maintain over time. By framing environmental ills as threats to one's chronic concerns, I suggest that chronic motivations, such as disease avoidance, can be leveraged to engender longer-lasting pro-environmental motivation. Specifically, I suggest that three distinct categories of environmental ills should be associated with distinct chronic concerns, and that the mechanisms that regulate these concerns should also regulate reactions to related environmental ills: pollution should engage a pathogenic disgust mechanism, wastefulness a moral disgust mechanism, and framing environmental outcomes as posing safety concerns should be linked to fear and anger mechanisms. Results of four experiments did not lend consistent support to the hypotheses. Neither situationally primed concerns nor motivation-relevant individual differences produced consistent results suggesting an association between the proposed motivations and the relevant environmental outcomes. / Dissertation/Thesis / Ph.D. Psychology 2012