Reconsidering reconsent: Threats to internal and external validity when participants reconsent after debriefing

We overwhelmingly utilize (partially) informed consent for, and debriefing of, human research participants. Also common is the practice of reconsent, particularly where changes in study protocols (or in participants themselves) occur midstream - participants consent again to remaining in the project or to having their data included. Worryingly under-discussed is post-debriefing reconsent, wherein participants can withdraw their data after learning more fully of the study's goals and methods. Yet, major ethics bodies in Canada, the United States and the United Kingdom promote such practice, with vague and potentially problematic guidelines. Here, the author provides examples involving such reconsent practice, highlighting potentially serious problems that are scientific (e.g. threats to internal and external validity) and ethical (i.e. to the participant, their peers, the researcher and society) in nature. Particularly, problematic is the introduction, by design, of unknowable bias in our research findings. For example, highly prejudiced participants could withdraw data from a discrimination study after learning of the study's hypotheses and goals. The practice may arguably contradict an Open Science goal of increasing research transparency. This call for discussion about the direction of psychological science methods aims to engage a broader discussion in the research community.