The thesis is divided into three parts. The first part is focused on the main theories of human mating strategies, such as sociosexual orientation and sexual strategies theory, which emphasizes intersexual differences as a result from the asymmetry of parental investment, and strategic pluralism theory, which highlights intrasexual variation in mating behavior. The second part consists of one review article published in the Encyclopedia of Evolutionary Psychological Science and one original research article published in The Journal of Sex Research, a peer-reviewed journal. In this part we explored possible evolutionary origins and adaptive values of paraphilic interests and their prevalence in the Czech population. The third part consist of one article published in the peer-reviewed journal Personality and Individual Differences and two research studies which are currently under peer-review in two international journals. The main aim of this part was to test whether individual differences in femininity-masculinity, Big Five personality traits, and propensity to sexual excitation and inhibition are associated with individual sociosexual orientation. A further aim was to test whether attention towards sexual stimuli is affected by an individual's level of sociosexual orientation and by depressive...

The main topic of this thesis is investigation of partner preferences and sexual behavior of female-to-male transsexuals. Number of previous studies showed that on average several partner preferences differ between men and women, and our goal was to determine if these preferences vary in female-to-male transsexuals during the process of sex change. The process of sex change includes intensive exposures to external levels of sex hormones, psychological therapy, and the transformation of their social role and overall life changes. Based on reviewe of the the scientific literature dealing with transsexuality, partner preferences and the potential impact of hormone therapy on sexually dimorphic traits, we developed a questionnaire focusing on partner preference and behavior. We obtained data from 36 heterosexual men transsexual female -to -male (i.e., sexual orientation focused on women) who were divided into three groups according to whether they were prior hormonal therapy (N = 11), whether have already started hormone therapy sex but not yet surgical change ( N = 11) and whether they were already after hormonal and surgical gender conversion (N = 14). In addition, we obtained data from 16 heterosexual non-transsexual men as a control group. Based on my previous bachelor research and literature...