Theoretical framework. A dwelling is not simply a space where people live. As Tognoli (1987) pointed out, the house is also a cognitive space. Csikszentmihalyi and Rochberg- Halton (1981) proposed that home is a place linked with feelings and emotions; furthermore, Rapoport (1972) considers houses to be social institutions. Hence, houses are psychosocial spaces (Aragonés & Rodríguez, 2005) where people arrange their lives. Residents modify and adjust the places where they live according to their preferences and tastes (Rapoport, 1972). This is related to Becker’s idea of personalization in which he pointed out that personalization of spaces allows residents to leave their own marks in said places (Becker, 1974). There is a group of studies that have demonstrated that daily environments are able to communicate much about their residents. For instance, Wilson and Mackenzie (2000) proved how people were classified in terms of age, socioeconomic status or family situation groups through analyzing their decorations. Other studies have also found that daily spaces such as rooms or offices are expressions of inhabitants’ personalities. Gosling, Ko, Morris and Mannarelli (2002), and Wells and Thelen (2002) discovered that places where people spend time every day are linked with aspects of the Big Five of Personality. In light of research revealing dwellings as crucial primary spaces that reflect personal and social identities, dwellings warrant further study that reveals more about links between inhabitants and their environments. This study primarily aims at researching how bedroom owners express their personal and social identities in their rooms through the personalization behaviours that occur within these rooms. Aims. The general aim of this research is to study how people establish links with spaces where they spend most of their time, and that are under their control. Hence, this research looks at feelings, thoughts and behaviours that occur inside of primary spaces. The supposition that residents adjust space according to their preferences could lead to the hypothesis that personal and social identities could be located by observing bedrooms. In this way, observers of such rooms could guess the personal traits of residents by analyzing the decoration of the bedroom. These personal traits would be tied to the factors of the Big Five. Methodology. The research will be carried out using students and old people. Participants will be required to fill out questionnaires that aim to reveal more about their feel- ings, activities and thoughts inside their bedrooms. In a second research, raters have to complete a questionnaire containing a list of adjectives (Saucier & Goldberg, 1996) that permits them to judge residents’ personal traits. These judgments will be documented after the raters observe slides of different bedrooms. In addition, personality questionnaires will also be filled out by the residents of these spaces. State of development of thesis. Results This thesis is based on several studies, some of which are still ongoing. However, several results have already been reported. Results from studies confirm the hypothesis that people are able to create links with daily spaces that reflect their identity. Residents experience emotions such as control, identity and intimacy in their bedrooms, and they consider these spaces mirrors of their personalities. Significant differences were found between male and female room owners in frequency production of categories related to affective aspects. Additionally, another study shows that raters point out more personal traits linked with Conscientiousness and Extraversion than with Agreeableness.