In today's lecture I mentioned that one of the characteristics of the effortful thinking that Kahneman calls System 2 is its limited capacity. The video here demonstrates this limitation in a very dramatic way. Follow the instructions and pay very close attention as you watch the video and assess the limits of your own effortful thinking.
Also in today's lecture I mentioned the idea that System 1 thinking doesn't usually come with any hint that there are alternatives to its products. It can be very difficult for one to recognize that he/she needs to step back, reflect, and engage in System 2 thinking. York psychologist Maggie Toplak is concerned with the question of whether children become better at recognizing the need for and engaging in rational thinking as they grow older. You can read a brief summary of her recent work here or the abstract of a recent paper here.