Abstract for: Does formal system dynamics training improve people's understanding of accumulation?
Prior work shows widespread misunderstanding of the principles of accumulation (stocks and flows), even among highly educated adults trained in Science, Technology, Engineering, and Mathematics. People fail to grasp that the quantity of any stock rises (falls) when the inflow exceeds (is less than) the outflow. Rather, people often use the correlation heuristic, concluding that a system's output is positively correlated with its inputs. Here I ask whether formal system dynamics training is effective in overcoming people's poor understanding of accumulation. I report an experiment with graduate students at the MIT Sloan School of Management to assess the impact of an introductory system dynamics course on their intuitive understanding of accumulation. I use a pretest-treatment-posttest design, where the treatment consisted of the standard course content. Results show improvement in overall performance and a reduction in the prevalence of the correlation heuristic. Even relatively modest exposure to stocks and flows improves intuitive understanding of these concepts, at least among these highly educated adults. However, there is still evidence of correlational reasoning among a minority of students. I suggest additional experiments to deepen our knowledge of the education and training required to develop people's intuitive understanding of accumulation.