Many medical experiments, including all of those described by the author of this article, do involve risks to participants. The rationale for such studies is to

Many medical experiments, including all of those described by the author of this article, do involve risks to participants. The rationale for such studies is to work out whether the benefits (if any) of an intervention justify the risks. The broad consensus in contemporary medical ethics is that people have the right to be informed adequately in advance and to make autonomous decisions about whether or not to join in a given clinical research study. The question by a parent of whether to subject an unborn fetus to a drug with a risk of causing congenital defects is categorically different than A/B testing responses to your site in yellow or blue.