Are post-error adjustments influenced by beliefs in free will? A failure to replicate Rigoni, Wilquin, Brass and...

In this pre-registered study, we tried to replicate the study by Rigoni et al. 2013 Cognition 127, 264-269. In the original study, the authors manipulated the participants' belief in free will in a between-subject design and subsequently measured post-error slowing (i.e. slower responses after an incorrect trial compared with a correct trial) as a marker of cognitive control. They found less post-error slowing in the group with reduced belief in free will (anti-free will group) compared with a control group in which belief in free will was not manipulated. In the present study, we used the same task procedure and the same free will manipulation (Crick text) in an attempt to replicate these findings. However, we used an online procedure and a larger sample size in order to address concerns about statistical power. Similar to the original study, we also used a questionnaire to measure beliefs in free will as an independent manipulation check. We found a difference in the scores on the questionnaire, thus a reduced belief in free will, after reading the Crick text. However, we did not find any difference in post-error slowing between the anti-free will and control groups. Our findings are in line with several other recent findings suggesting that the Crick text manipulation affects the participants' self-reported belief in free will but not their behaviour. The present study can be considered a high-powered failed replication attempt.