IntroductionThe quality of health-care related decision making plays an important role in the overall quality of healthcare. Health professionals are involved in a permanent process of decision making, which includes decisions on diagnostics procedures, interventions or treatment costs (Halama, 2013). Decision making in the area of healthcare may have serious consequences including human and economic harm (Gurnakova, 2011). It is considered a complex, or even complicated process, because of many possible diagnoses or therapeutic procedures, as well as the need to involve patients' preferences or economic aspects (Hunink et al., 2001). Chapman and Sonnenberg (2000) also emphasize that healthcare is a very specific area for investigating decision making, because it includes such aspects as uncertainty of results, or multiple alternatives for a problem solution.In this study, we focused on a specific health profession: nurses. The nurse profession in hospitals can be defined primarily as providing basic medical and physiological care for hospitalized patients, usually under the control of physicians. Although limited in their autonomy, nurses make various decisions connected with the care for patients on a daily basis. These decisions are related to specific ways of providing care for patients, monitoring their functioning, calling for physicians, and more.The nurses provide care not only at a physiological level, but also at a psychological and social level (Chen et al., 2005). Social aspects of their work and decision making are very important because they continuously interact with people of various social positions (physicians, patients, colleagues, relatives, etc.). The assumption that social context of the care substantially affects decision making of nurses was confirmed by qualitative research studies in different medical areas, such as end-of-life care (Galagher et al., 2015) or intensive care (Tingsvik et al., 2015). These studies suggest that the decisions that nurses make are not made independently of social environment; in their decisions, nurses are affected by social influences and relationships.One of the factors affecting decision making is personality of the decision maker. Previous research showed that decision making is related to personality characteristics in different situations and in different persons (e.g., Di Fabio & Palazzeschi, 2012; Lauriola & Levin, 2001) including health professionals (Pilarik & Sarmany-Schuller, 2011; Kamhalova et al., 2013). It was also shown that decision making in social context is related to socially relevant personality variables such as extraversion (Halama & Gurnakova, 2014) or agreeableness (Halama, 2013).One of the dominant social variables applied in current personality research is attachment. The theory of attachment was originally developed by Bowlby (1969/1997) as a clinical theory used to explain the developmental aspects of mental disorders in children. It was based on the assumption that the nature of the relationship between child and his or her primary caregiver significantly affects the feelings and behavior of the child. Later, this theory was applied as a research framework for different adult behaviors, especially in close relationships (e.g., Feeney & Noller, 1996; Simpson & Rholes, 1998; Mikulincer & Shaver, 2007). This was based on the fact that certain similarities exist between child attachment behavior and behavior of the adult person in close relationships. Like a child, an adult person also seeks proximity of a close person, especially in times of discomfort, and derives feelings of safety from his or her presence (Feeny, 1999). Adult attachment system was described as a cognitive system involved in a continuous monitoring of internal and external events in regard to possible threats and activating security based strategies of behavior (Mikulincer & Shaver, 2007).Individual differences in attachment system are defined as attachment styles. …