Environmental variation and the maintenance of polymorphism : the effect of ambient light spectrum on mating behaviour and sexual selection in guppies

The intensity of sexual selection is influenced by environmental conditions because these conditions influence signal propagation and the risks of the signal being exploited by predators and parasites. We explore the possibility that spatial or temporal heterogeneity in environmental signalling conditions (in this case light spectrum) may induce fluctuating sexual selection on male behaviour and ornamentation in guppies. We used shade cloth and filters to experimentally manipulate light spectrum, mimicking conditions found naturally: early morning/late afternoon light (SC treatment), midday forest shade (F89 filter treatment) and midday woodland shade (F55 filter treatment). Females were more responsive to male courtship and males were less likely to attempt sneak copulations under F55 light than the other two treatments. By contrast, male display rate was not influenced by treatment. Females tended to prefer the same males under SC and F55 light, but attractiveness in these treatments was unrelated to attractiveness under F89 light. There were similarities among treatments in the traits that females preferred: females preferred males with larger areas of orange in all three treatments. There were, however, also some differences, including preference for larger males under F89 light and for smaller males under the other treatments. Overall, the influence of ambient light spectrum on the relative importance of mate choice and male sneak copulation may have important implications for the mode and strength of sexual selection in different environments. The findings on attractiveness and preference functions, however, suggest that light spectrum only weakly affects the direction of sexual selection by female choice.

Fracturing the façade : exploring the impact of childhood sexual abuse

Examination of previous empirical literature illustrates how researchers have concentrated on documenting the impact of childhood sexual abuse (CSA) on the later psychological functioning of survivors, through comparisons with those who have not had such a history. Only more recently has there been a focus on assessing the relationship between aspects of the abuse and specific psychological difficulties. This thesis investigated the relationships between CSA characteristics and women’s later psychological adjustment. The role of attributions, coping methods, parenting competency and marital satisfaction were also investigated. Qualitative data on perception of benefit and general reflections of participants were used to explore participants’ self-esteem, locus of control, decisions relating to parenting, disclosure experiences, and attributions in relation to their abuse, including the search for meaning. Recruitment through newspapers and counselling services led to 118 women volunteering to complete a questionnaire evaluating the characteristics of their CSA and their current psychological adjustment. Of this group, 33 subsequently volunteered to participate in a telephone interview that explored in greater depth issues related to the long-term impact of their CSA. Both quantitative and qualitative analyses were conducted on the data. The women reported a high prevalence of dysfunction in their families of origin. Abuse had generally commenced by middle childhood, and lasted for a number of years and often involved a number of perpetrators. Perpetrators were most likely to be intrafamilial, with stepfathers being over-represented. Sexual activities generally involved physical contact, with participation often induced by the use of coercion. Participants demonstrated significant difficulties in psychological adjustment, but attributions regarding the abuse improved over time. Some concerns were expressed regarding parenting competency, and avoidant coping methods were favoured. In general, participants were satisfied with their current marital relationship. Significant associations were found between coping methods, attributional style, beliefs and various psychological adjustment measures. Participants, in general, demonstrated low self-esteem and displayed an external locus of control. As a consequence of their experience of CSA, many participants reported they had decided not to have children. For those who did have children, CSA was almost universally seen as having had an impact on their parenting. Disclosure of CSA was usually delayed for a number of years, with poor outcomes generally resulting from disclosure when it occurred. Women with current partners rated them as very caring and not controlling. Participants were generally still searching for meaning in their abuse, despite many having accepted it. Survivors outlined an extensive range of long-term effects of CSA, and nominated a number of strategies that would assist in reducing these effects. The results of the study indicated that there are a number of characteristics associated with CSA which signal a higher risk of difficulties in psychological adjustment. Concerns of survivors regarding parenting were confirmed according to those who undertook this role. Unfortunately, concerns expressed by survivors that disclosure of their CSA would have had negative consequences was usually the case when they did finally disclose. However, the accessing of social and family support appeared to have an important role in changing the attributions of survivors regarding their CSA. Furthermore, change of attributions in relation to abuse may provide the key to resilience in survivors against the negative impact of CSA on later psychological adjustment.

Women's cognitive and emotional processing during sexual arousal : the effects of erotic film and absorption

Sexual arousal is a complex and dynamic element of women’s sexuality. Accounts vary, however most multidimensional models highlight the cognitive, affective and physiological components of the female sexual arousal response. While literature examining the peripheral physiological changes that occur during female sexual arousal abounds, there has been a dearth of literature pertaining to the cognitive and affective components. Thus, while many authors have included cognitive and emotions as independent components of the female sexual arousal response, there has been little empirical research to validate this approach. The aim of the current thesis was to examine the cognitive and affective components of female sexual arousal in more depth, investigating the nature of the relationship between these components under various experimental conditions. In order to do so, two integrated studies were conducted, each highlighting the effects of either external or internal variables on women’s subjective sexual arousal, absorption, positive affect and negative affect. Study One was designed to evaluate women’s emotional and cognitive processing of two elements of erotic film – foreplay and erotic context. 60 women were asked to report their subjective sexual arousal, absorption, positive affect and negative affect in response to one of four erotic film excerpts. The erotic excerpts varied in accordance with the degree of foreplay (low vs. high) depicted and the context in which the sexual activities took place (novel vs. habitual context). Women in the study responded more favourably to the high foreplay erotic film excerpt, subsequently reporting higher degrees of subjective sexual arousal, absorption and positive affect. Women also responded favourably to the erotic excerpt filmed in a novel context, reporting greater subjective sexual arousal as a result. The environment in which the sexual encounters were filmed failed to have an effect however, on women’s absorption or their positive or negative affect. The results of Study One suggest that stimulus specific variables, such as the degree of foreplay depicted, have a significant influence on female cognitive and emotional processing of erotic film. The results also suggest that a relationship exists between absorption, subjective sexual arousal and positive affect, albeit a correlational one. Specifically, there was evidence of parallel processing during sexual arousal, as participant reported sexual arousal, absorption and positive affect all increased and decreased in unison. Based on the results it was suggested that future research attempt to experimentally manipulate one of these variables, to examine its direct effect on the remaining variable. Thus, Study Two aimed to examine the effects of absorption on women’s cognitive and emotional processing of erotica. Study Two manipulated absorption at two levels (high vs. low), examining the impact of these states on participants’ subsequent absorption, subjective sexual arousal and positive and negative affect. 62 women were asked to read one of two sets of test session instructions. The first, participant-oriented instruction set, instructed participants to immerse themselves in the erotic film excerpt, as if they were active participants in the sexual exchange. The second, spectator-oriented instruction set, directed participants to observe and evaluate the erotic film. These instructions were designed to elicit high and low degrees of absorption, respectively. The utility of this approach when manipulating female absorption, was demonstrated by self reported ratings of absorption, given at the conclusion of the film presentation. Participants were also asked to report their subjective sexual arousal and positive and negative affect at the conclusion of the erotic film presentation. The findings of this study suggest that the adoption of a participant-oriented (high absorption) perspective elicits more favourable responses from participants than a spectator-oriented (low absorption) perspective, with participants in the former experimental group reporting greater degrees of subjective sexual arousal and positive affect. Negative affect was equivalent across experimental conditions, with the participants reporting that they experienced little to no aversive feelings during either of the experimental conditions. The results suggest that the degree to which a women immerses and absorbs herself in a sexual stimulus has a significant impact in her subsequent cognitive and affective processing of that stimulus. More specifically, it appears that women respond more favourably when they are highly absorbed and immersed in a stimulus, reporting greater subjective sexual arousal and positive affect. Overall, the results of Studies One and Two highlight the dynamic and complex nature of female sexual arousal. It appears that women have definite cognitive and affective responses to sexual stimuli. The magnitude of these responses may be mediated by a number of factors however, including the intrinsic qualities of the stimulus and the degree to which the woman attends to the stimulus. Both these variables act to either enhance or inhibit the sexual arousal response. There results have important implications for current sexuality literature. While women’s cognitions and emotions in response to erotic film were generally highly correlated, in some instances they differed, warranting their inclusion as separate elements in models of female sexual arousal. Furthermore, it might be suggested that the inclusion of an additional variable – absorption – into current models of female sexual arousal would prove beneficial, aiding researchers to better understand and predict the arousal process. As such, recommendations are made for a revised model of female sexual arousal. In terms of future directions, the results of the present thesis have implications for the treatment of sexual dysfunctions, suggesting that clinicians need to understand the internal and external variables that might contribute to the aetiology and maintenance of their presenting problems.

Development of a model to explain the sexual beliefs, intentions and behaviours of adolescents and young adults

In the last thirty years there have been many research studies which have examined the reasons why adolescents and young adults engage in sexual behaviours. Most of these studies have lacked a theoretical basis, Consequently there are many links made between variables, but no consistency across studies, or attempts to develop an underlying theory to explain the results. However, there have been theoretical models developed to explain adolescents’ and young adults’ sexual decision making. Unfortunately, many of these models have not been empirically validated. This thesis attempts to address these deficiencies in the literature by utilising a theory of behaviour and applying it to adolescent and young adult sexual decision making. This theory is the Theory of Planned Behaviour (TPB). Two longitudinal studies were conducted to examine the utility of an adaptation of the TPB to sexual decision making among adolescents and young adults. In the first study 58 adolescent males, aged between 14 years and 18 years participated in a longitudinal study using a questionnaire adapted from the Depth of Sexual Involvement Scale. In the second study, 194 young adults (156 female, 38 male) aged between 18 years and 21 years participated in a similar study. The first study found that intention to engage in behaviour was well predicted, although some of the variables in the model, did not in fact, contribute significantly to the prediction. The prediction of behaviour was less strong than that of intention. Study two found that intention to engage in behaviours was well predicted by the model. However, the degree to which intention led to behaviour was not well predicted. Overall, the results of these studies suggest that the TPB is a good theoretical basis from which to launch a systematic and theoretically informed explanation of adolescent and young adult sexual decision making. However, other factors may need to be added to the model to fully describe the decision making process and accurately predict behaviour. Suggestions are made for future research, as well as interventions that may arise as more knowledge is gathered using this paradigm.

Attitudes and perceptions of workers to sexual harassment

This thesis highlights the importance of workers’ perceptions of and attitudes to sexual harassment. Past researchers have found that a variety of individual factors (age, gender, gender role, and past experiences of sexual harassment), and organisational factors (gender ratio, sexual harassment policies and the role of employers), correlate with the incidence of sexually harassing behaviours. Two studies presented in this thesis extend this research and were designed to investigate how these factors relate to workers’ attitudes towards and perceptions of sexual harassment. Study one investigated 176 workers from a large, white-collar organisation. Study two sampled 75 workers from a smaller, blue-collar organisation. By comparing two different workplaces the effect of the organisational climate was investigated. Individuals from Study two experienced more sexual harassment, were more tolerant of sexual harassment and perceived less behaviour as sexual harassment compared with individuals from Study one. The organisational context was found to affect the way in which organisational and individual factors related to workers' attitudes to and their experiences of sexual harassment. However, the factors that influenced workers’ perceptions of sexual harassment were stable across both studies. Although workers’ attitudes to and their perceptions of sexual harassment were significantly correlated, they were influenced by different factors. Overall, workers’ perceptions of sexual harassment were influenced by their attitudes, the behavioural context, and the gender of the victim and perpetrator. In contrast, attitudes to sexual harassment appeared to be more strongly influenced by individual factors, such as age, gender, gender role, past experiences of sexual harassment, and perceptions of management’s tolerance of sexual harassment. The broader implications of these findings are discussed and recommendations for future research are suggested.

The effects of treating male hypogonadism on couples' sexual desire and function

Introduction: Hypogonadism is a common endocrine condition characterized by low levels of testosterone (T) and marked by numerous symptoms, one of which is low sexual desire. Studies comparing T delivery systems have suggested that hypogonadal men’s partners may be at risk from exposure to T gels. Little other mention is found of the impact of hypogonadism and its treatment on a man’s partner and the couple’s sexual function.

Aim: To assess sexual desire and sexual function in hypogonadal men and their woman partners before and after treatment with T replacement therapy.

Methods: Twenty-one hypogonadal men and 18 partners were recruited from a   tertiary endocrine clinic, and were compared with a control group of 20 eugonadal age-matched men and their partners. All men had baseline blood tests to confirm their status as hypogonadal or eugonadal, and hypogonadal men repeated tests at 3-month intervals. All participants completed the Sexual Desire Inventory (SDI) and sexual function questionnaires at baseline and at 3-month intervals until the hypogonadal men attained normal T levels.

Main Outcome Measures: Pre- and post-treatment SDI and sexual function questionnaires were compared once T normalization was achieved. Between- and within-group comparisons were carried out.

Results: Pretreatment hypogonadal men recorded lower levels of sexual desire and function than controls, but significantly improved once hypogonadism was corrected. Eugonadal controls recorded no significant changes in either sexual desire or function during the study. Partners of the hypogonadal men reported no changes on the SDI, but significant improvements in sexual function as their partners recovered.

Conclusion: SDI and sexual function measures reflect sexual changes that  accompany rising serum T levels during correction of male hypogonadism. Women partners reported more satisfaction, less pain, and improved sexual function following the men’s treatment. Treatments affecting one partner potentially have important effects on the other.

Female university students' perceptions of a sexual assault when victim and perpetrator gender are varied

This study examines the general impressions and blame attributions of Trinidadian university students in cases of sexual assault. Participants were 132 female students from the University of the West Indies, Faculty of Social Sciences. Each respondent read one of four sexual assault scenarios, in which victim and perpetrator gender were varied. Participants' impressions of the incident, opinions about each party's behaviour, blame attributions, attitudes about reporting the incident to the police, desired outcome, and their reasons for these were then assessed. Consistent with Burt's rape myth theory, the qualitative and quantitative results showed a tendency for participants to attribute an internal locus of control to female victims, and to blame them more than males. Although same sex events evoked significantly more emotional and disgust-related reactions, these reactions did not translate into different seriousness scores, or different ideas about whether the victim should report the incident to the police. Although respondents showed an ability to separate their initial reactions from their attitudes about the legal status of the event, many of the response patterns indicated gender role biases on the part of these future professionals.

Female sexual dysfunction

This thesis examined the aetiology of female sexual dysfunction (FSD) and a model to represent sexual function. Relationship factors were the main predictor of sexual function for women with FSD. A circular model of sexual response represented women's sexual experience for those with FSD and those who did not have FSD. In order to illustrate the role of family emotional involvement in children's development of psychological disorders the portfolio presents and explores four case studies.

A cross-cultural examination of social and sexual behaviour in High Functioning Autism and Down Syndrome

The focus of this research was to obtain an understanding of the social and sexual behaviour of adolescents with High Functioning Autism (HFA) or Down Syndrome (DS) in comparison to Typically Developing (TD) adolescents across cultures. The findings highlight the importance of cross-cultural research and indicate the need for sex education. The portfolio presents four case studies which support the proposition that insecure attachment is only likely to lead to depression in the presence of socially-related and other psychological difficulties, since not all insecurely attached children develop depressive symptoms.

Body image and psychological, social, and sexual functioning

This thesis examined the nature of the body image construct, as well as the relationships between body image and self-esteem, depression, anxiety, and social functioning. Body image was demonstrated to play an important role in the everyday lives of adolescent boys and girls, and men and women throughout adulthood.