Background: The Thinking Styles Inventory-developed by Sternberg and Wagner based on Sternberg's (1988, 1997) earlier theory of mental self-government-was selected for the research in order to assess thinking styles of student teachers. Another reason is that the theoretical constructs, as well as the inventory generated from the theory, have proved to be valuable to assess thinking styles of people in several studies. For example, previous research reported that students differed in their thinking styles depending on their personal characteristics (e.g., Sternberg & Grigorenko, 1995; Zhang, 1999, 2002b, 2001e). However research found no distinct patterns between thinking styles and personal characteristics of students (e.g., Grigorenko & Sternberg, 1997; Zhang, 2002a). Little research has focused on the study of non-Western students' thinking styles. Thus, it is reasonable to expect that the thinking styles could also be identified among student teachers in Turkey since the styles are differentiated within a different country and culture.