On the Physiology of Investment Biases: The Role of Cortisol and Testosterone

The underlying physiological mechanisms of biases are not well understood. As such, we examine the impact of testosterone and cortisol levels on several commonplace investment biases using realistic trading simulations. Cortisol, the biological marker of stress, is positively related to the disposition effect and portfolio turnover, which is consistent with the relation between judgment errors and stress in social settings. Testosterone, the male hormone, is also positively related to portfolio turnover, which is consistent with androgen-driven behaviors. Overall, the results show that the endocrine system plays a significant role during financial decision-making, that has important consequences for the financial industry.