Given the importance of decision making and the sensitivity of this issue in stock exchange trading, this study aimed to predict decision-making styles based on behavioral brain systems; The mediating role of self-differentiation in stock exchange traders.

In this descriptive-correlational study, the statistical population included all stock exchange traders of Tehran city Stock Exchange in the Jan-March2020. Participants were 165 cases after deleting invalid questionnaires. Participants selected by convenience method and completed questionnaires of decision-making styles (Scaht & Borus, 1995), behavioral brain systems (Carver & Whight, 1994), and self-differentiation (Scorn & Freelander, 2003). Data analysis in this study was performed by multivariate regression analysis and path analysis.

 The results showed that the effect of behavioral inhibition and behavioral activation was significant on self-differentiation and behavioral activation had a positive and stronger effect (0.92). Self-ditermination had a significant effect on intuitive, logical and dependent decision-making styles of 0.40, 0.70 and -0.92, respectively. The strongest effect was seen in the dependent decision-making style, which was negative and significant.

Thus, the mediating role of self-differentiation between decision-making styles and behavioral brain systems was confirmed