Legal but immoral: attitudes toward non-invasive brain stimulation for cognitive enhancement

Cognitive enhancement involves using substances or technologies to improve mental performance in healthy individuals. While methods such as caffeine are widely accepted, others, including prescription stimulants and non-invasive brain stimulation (tDCS), evoke ethical concern. This study examined how university students evaluate three forms of cognitive enhancement (natural, pharmacological, brain stimulation) across five moral domains: academic fairness, free will, naturalness, self-identity, and safety. We also tested how evaluations were shaped by framing (preservation vs. enhancement) and priming (self-affecting vs. non-self-affecting). A total of 449 students completed an online experiment with a 2 x 2 x 3 mixed design, rating enhancement acceptability after reading intervention-specific scenarios. Natural enhancers were judged most positively, followed by brain stimulation and then pharmacological agents. Importantly, although brain stimulation is legal and marketed as non-invasive, it was evaluated more like pharmacological enhancement than natural methods, indicating that legality does not equate to moral acceptability. Framing effects showed that participants were more accepting of enhancement when it was described as preserving ability rather than augmenting it beyond baseline. Priming participants to consider how others use might affect their own outcomes reduced moral acceptability, particularly for pharmacological and brain stimulation methods in the domain of academic fairness. Overall, public attitudes toward enhancement appeared shaped less by legality or objective safety than by intuitive moral reasoning. These findings highlight the importance of adopting pluralistic, context-sensitive approaches to policy and regulation, as student judgments reflect concerns about fairness, authenticity, and competition in academic life.