UC Berkeley

For more than 30 years, "the Libet experiment" has inspired and dominated philosophical and scientific discussions of free will and determinism. Unfortunately, this famous experiment has been compromised by a serious confounding variable (i.e., there has been no control for watching the clock), and the method of data collection ignored conscious mental activity that occurred prior to the decision to act. Because Libet's results appear to be wholly an artifact of his method, his experiment should be discounted in future discussions of the problem of free will.