How good are we at finding optimal solutions to complex prob
Scientific studies that assess these strategies routinely apply a puzzle called the two-step task, which is similar to the second, more complex, scenario.

Even with extensive experience with the task, only a small minority of the 200-subjects group developed a model-based strategy. This is striking given the relative simplicity of the task and suggests that humans are surprisingly poor at learning causal models from experience alone.

At the end of the third session, the researchers split subjects into two groups. One group received the full description of how the puzzle works, while the other did not. Then, the researchers ran a fourth and final session to test the effect of receiving instructions on the subjects' problem-solving approach.

The difference between the two groups was clear: almost all the subjects from the "explanation" group—both healthy volunteers and OCD patients—adopted a model-based strategy. On the other hand, most test subjects of the other group carried on with the model-free approach.