Elena Tsankova

• First impressions of trustworthiness are formed quickly and can have long-term consequences. The literature proposes a large number of factors that could influence first impressions of trustworthiness. However, there exists no single integrative line of research that studies the relative importance and the combined effects of these factors on the first impression of trustworthiness. Therefore, it was the purpose of this dissertation to provide a first systematic investigation in this direction. The PhD project focused on three main groups of factors – those relating to the impression holder (e.g., personality), those relating to the impression target (e.g., structural facial qualities), and those relating to the physical environment (e.g., temperature). Five experiments were conducted that addressed the ways in which these factors affected the trustworthiness impressions – both in isolation and in combination with one another. The results clearly indicate a considerable role of the physical appearance of the impression target in the formations of the trustworthiness impression, whereas the relative importance of the personality of the impression holder and the physical environment appear less straightforward and pose interesting questions for future research. The implications of the findings for theory, research, and everyday life are discussed, limitations of the project are pointed out, and suggestions are put forward regarding the next steps in the study of the factors influencing the first impression of trustworthiness.