[pt] O investimento emocional é um traço referente à disposição em investir emocionalmente nos relacionamentos. Em geral, quanto maiores os níveis de investimento emocional, maior a tendência a estabelecer relacionamentos compromissados e satisfatórios. Esta pesquisa teve como objetivo verificar a relação entre investimento emocional, sociossexualidade (tendência a ter relacionamentos casuais) e satisfação com o relacionamento. Para isso, foram desenvolvidos dois estudos. O primeiro estudo teve como objetivo construir uma escala para aferir o investimento emocional, bem como buscar suas evidências de validade e precisão. Os resultados desse estudo indicaram que a escala de Investimento Emocional apresenta estrutura de dois fatores, denominados Romantismo e Carinho, com adequados índices de consistência interna. O segundo estudo teve como objetivo testar o papel mediador da sociossexualidade na relação entre investimento emocional e satisfação com o relacionamento. O investimento emocional exerceu um impacto positivo na satisfação com o relacionamento e um impacto negativo na sociossexualidade, que por sua vez, exerceu um impacto negativo na satisfação com o relacionamento. A sociossexualidade mediou a relação entre investimento emocional e satisfação com o relacionamento, tornando a magnitude da relação mais fraca. Os achados desta pesquisa nos ajudam a compreender melhor a dinâmica dos relacionamentos românticos, sobretudo a sua manutenção. / [en] Emotional investment is a trait referring to the tendency to invest emotionally in relationships. In general, the higher the levels of emotional investment, the greater the tendency to establish long-lasting and satisfying relationships. This research aimed to verify the relationship between emotional investment, sociosexuality (tendency to have short relationships), and satisfaction with the relationship. For this purpose, two studies were developed. The first study aimed to elaborate a scale to measure emotional investment and search for validity evidence and precision. This study indicated that the Emotional Investment scale has a two-factor structure, called Romanticism and Affection, with adequate internal consistency indices. The second study aimed to test the mediating role of sociosexuality in the relationship between emotional investment and satisfaction with the relationship. Emotional investment had a positive impact on satisfaction with the relationship and a negative impact on sociosexuality, which had a negative impact on satisfaction with the relationship. Sociosexuality mediated the relationship between emotional investment and satisfaction with the relationship, resulting in a weaker magnitude of the relationship. This research s finding helps us better understand the dynamics of a romantic relationship, especially its maintenance.

Evolutionäre Herangehensweisen hatten in der Persönlichkeitspsychologie nicht den gleichen Erfolg wie in anderen Bereichen der Psychologie. In dieser Dissertation werden zwei alternative evolutionäre Herangehensweisen an die Persönlichkeitspsychologie diskutiert und angewendet. Die evolutionsgenetische Herangehensweise fragt, warum genetische Varianz in Persönlichkeitsunterschieden existiert. Im ersten Teil dieser Dissertation werden verschiedene evolutionsgenetische Mechanismen, die genetische Varianz erklären können, verglichen. Auf Grundlage evolutionsgenetischer Theorie und empirischen Befunden aus der Verhaltensgenetik und Persönlichkeitspsychologie wird geschlussfolgert, dass ein Mutations-Selektions-Gleichgewicht genetische Varianz in Intelligenz gut erklären kann, während ausgleichende Selektion durch Umweltheterogenität die plausibelste Erklärung für genetische Unterschiede in Persönlichkeitseigenschaften ist. Komplementär zur evolutionsgenetischen Herangehensweise beginnt die „Life History“-Herangehensweise damit, wie Menschen ihre Ressourcen in evolutionär relevante Lebensbereiche investieren. Im zweiten Teil der Dissertationsschrift wird diese Herangehensweise am Beispiel von Investitionsunterschieden in Langzeit- versus Kurzzeit-Paarungstaktiken (wie im Konstrukt der Soziosexualität abgebildet) erläutert. Zwei neue Maße zur Erfassung von Soziosexualitätskomponenten werden vorgestellt. Während das revidierte Soziosexuelle Orientierungsinventar (SOI-R) ein Fragebogen zur Erfassung der Facetten „Verhalten“, „Einstellung“ und „Begehren“ ist, wurde mit dem Single-Attribute Impliziten Assoziationstest (SA-IAT) eine neue Methode zur indirekten Erfassung impliziter Soziosexualität entwickelt. Beide Maße zeigten konkurrente Validität in Onlinestudien, aber nur der SOI-R erwies sich als prädiktiv für Paarungstaktiken, einschließlich beobachtetem Flirtverhalten sowie der Zahl der Sexualpartner und Veränderungen im Beziehungsstatus innerhalb der nächsten 12 Monate. / Evolutionary approaches have not been as successful in personality psychology as they were in other areas of psychology. In this thesis, two alternative evolutionary approaches to personality psychology are discussed and applied. The evolutionary genetic approach asks why genetic variance in personality differences exists. In the first part of this thesis, three evolutionary genetic mechanisms that could explain genetic variance in personality differences are assessed: selective neutrality, mutation-selection balance, and balancing selection. Based on evolutionary genetic theory and empirical results from behavior genetics and personality psychology, it is concluded that selective neutrality is largely irrelevant, that mutation-selection balance seems best at explaining genetic variance in intelligence, and that balancing selection by environmental heterogeneity seems best at explaining genetic variance in personality traits. Complementary to the evolutionary genetic approach, the life history approach starts with how people allocate their resources to evolutionarily relevant life tasks. In the second part of this thesis, differences in the allocation to long-term versus short-term mating tactics (as reflected in the construct of sociosexuality) are used as a case to exemplify this approach. Two new measures for the assessment of sociosexuality components are presented. While the revised Sociosexual Orientation Inventory (SOI-R) is a questionnaire that assesses the facets Behavior, Attitude and Desire, the sociosexuality Single-Attribute Implicit Association Test (SA-IAT) is a new methodic development aimed to assess implicit sociosexuality indirectly. Both measures showed concurrent validity in online studies, but only the SOI-R facets were predictive of mating tactics, including observed flirting behavior, as well as for the number of sexual partners and changes in romantic relationship status over the following 12 months.

L’étude de la sexualité dans le contexte des maladies neurologiques est un domaine émergent qui nous permet de mieux comprendre les corrélats cérébraux et neurocomportementaux de divers aspects de la sexualité. Les changements au sujet de la sexualité sont fréquents à la suite de troubles neurologiques tels que les blessures de la moelle épinière, la sclérose en plaques, l’accident vasculaire cérébral, l'épilepsie et les traumatismes craniocérébraux (TCC). Compte tenu de la complexité de la sexualité après un TCC, celle-ci doit être analysée à partir d'une perspective biopsychosociale qui comprend trois facteurs interdépendants : a) les facteurs neuropsychologiques et psychologiques, b) les variables médicales et physiques, et c) les facteurs relationnels. L’objectif de cette thèse était d’étudier certains éléments de la sexualité auprès de personnes ayant subi un TCC afin de fournir des preuves empiriques pour contribuer à la validation d’une perspective biopsychosociale de la sexualité après un TCC. Trois études quantitatives originales ont été effectuées auprès de personnes ayant subi un TCC léger, modéré ou grave et ayant reçu des services de réadaptation post-TCC, et d’un groupe de témoins en bonne santé, tous vivant dans la communauté. Les groupes étaient comparables en ce qui concerne l’âge, le sexe, le nombre d’années de scolarité, le statut d’emploi et relationnel, et le revenu annuel. Les variables ciblant la sexualité, incluses dans cette thèse, étaient la qualité de vie sexuelle, le comportement sexuel à risque, et la sociosexualité (p. ex., les différences individuelles en ce qui concerne la volonté d’une personne à avoir des relations sexuelles sans engagement). Les variables neuropsychologiques et psychologiques incluaient les fonctions exécutives, la dépression et l’anxiété. Les aspects médicaux et physiques englobaient les symptômes postcommotionnels. Les facteurs relationnels comprenaient les attitudes envers l'infidélité. Les résultats démontrent que par rapport aux témoins en santé, les individus avec un TCC ont montré une diminution de la qualité de vie sexuelle, alors que les groupes étaient comparables sur le plan du comportement sexuel à risque, de la sociosexualité et des attitudes envers l'infidélité. Par ailleurs, les résultats ont montré une différence entre les hommes et les femmes sur le plan de la sociosexualité (p. ex., plus restrictive chez la femme). Chez les personnes ayant subi un TCC, une faible qualité de vie sexuelle était significativement associée à un nombre élevé de symptômes postcommotionnels, un comportement sexuel plus à risque corrélait avec une plus grande fréquence de symptômes dysexécutifs, et une plus faible acceptation de l'infidélité était liée à une sociosexualité moins restrictive. Les résultats de ces trois études soutiennent une perspective biopsychosociale de la sexualité après le TCC. Elles apportent des connaissances nouvelles en ce qui a trait aux domaines de la sexualité qui peuvent être touchés après un TCC, ainsi qu’à certaines variables neuropsychologiques et psychologiques, médicales et physiques, et relationnelles qui sont associées à ces changements. Les implications théoriques, ainsi que pour la pratique clinique et la réadaptation sont discutées. Les limitations des études sont présentées et des recommandations pour la recherche sont proposées. Le modèle biopsychosocial peut être utilisé comme une référence pour guider la recherche future dans ce domaine. D’autres études sur la sexualité et le développement d'interventions multidisciplinaires dans ce domaine pour les personnes TCC sont nécessaires. / The study of sexuality in the context of neurological disorders is an emerging area leading us to better understand the brain and neurobehavioral correlates of various aspects of sexuality. Changes in sexuality are common following neurological disorders, such as spinal cord injury, multiple sclerosis, stroke, epilepsy, and traumatic brain injury (TBI). Given the complexity of sexuality after TBI, it needs to be analyzed from a biopsychosocial perspective that includes three interrelated factors: a) neuropsychological and psychological factors, b) medical and physical variables, and c) relationship factors. The objective of this thesis was to study certain aspects of sexuality in individuals with TBI to provide empirical evidence to contribute to the validation of a biopsychosocial perspective of sexuality after TBI. Three original quantitative studies were conducted in individuals with mild, moderate, and severe TBI who received post-TBI rehabilitation services and in a group of healthy controls living in the community. The groups were comparable in age, sex, years of education, work and relationship status, and annual income. The variables targeting sexuality included in this thesis were sexual quality of life, risky sexual behavior, and sociosexuality (e.g., individual differences regarding the willingness to engage in uncommitted sexual relationships). Neuropsychological and psychological variables included executive function, depression and anxiety. Medical and physical aspects encompassed postconcussion symptoms. Relationship factors involved attitudes toward infidelity. The results demonstrate that compared to healthy controls, individuals with TBI showed lower sexual quality of life, while the groups were comparable in risky sexual behavior, sociosexuality, and attitudes toward infidelity. Furthermore, the results showed differences between men and women regarding sociosexuality (e.g., more restrictive in women). In individuals with TBI, lower sexual quality of life was significantly associated with the presence of post concussion symptoms; an increase in risky sexual behavior correlated with greater frequency of dysexecutive symptoms, and lower acceptance of infidelity was linked to a less restricted sociosexuality. The results of these three studies support a biopsychosocial perspective of sexuality following TBI. They provide new knowledge in the areas of sexuality that may be affected after a TBI, as well as some neuropsychological and psychological, medical and physical, and relational variables associated with these changes. The theoretical implications, as well as those related to clinical practice and rehabilitation are discussed. The limitations of the studies are presented and recommendations for research are proposed. The biopsychosocial model can be used as a reference to guide future research in this area. Other studies about sexuality and the development of multidisciplinary interventions in this area for individuals with TBI are warranted.