Ivar Hannikainen

The current revival of interest in classic psychedelics and other psychoactives such as ketamine and MDMA, coupled with changes to their regulatory status in many jurisdictions, necessitates rigorous ethical guidelines both within and beyond clinical and scientific contexts. This paper examines crucial ethical, philosophical, and policy considerations needed to ensure psychedelic use across various settings remains equitable, beneficial, consensual, and safe, with appropriate accountability mechanisms for addressing potential harms. We seek to broaden the lens beyond the medical model of psychedelics to include potentially valuable non-medical applications that could benefit individuals, communities, and society. With popular interest in psychedelics growing outside of therapeutic and research settings, there is a need to determine which aspects of any proffered guidelines, or underlying principles, should be applied similarly across contexts and in what ways there should be flexibility and/or context-sensitivity in their interpretation or application. In developing such guidelines, we suggest the “treatment versus enhancement” distinction – and associated debates familiar from bioethics and philosophy of medicine – requires renewed attention. We argue that neglecting non-medical and broad scientific use cases for psychedelics may have important implications for a range of ethical issues surrounding psychedelic use and research, including concerns about psychedelic hype and exceptionalism (both positive and negative), therapeutic touch, informed consent, data-gathering, and balancing access and safety. We conclude with suggestions for future directions in research and policy in the burgeoning area of psychedelic bioethics, stressing the importance of incorporating the perspectives of a diversity of stakeholders and fostering cross-sector collaboration.

Philosophers have argued that people with psychiatric conditions are vulnerable to epistemic injustice because their testimony is systematically, and unjustly, discredited relative to psychotypical individuals. Whether such differences in credibility amount to epistemic injustice is a normative question, yet whether and how they occur is an empirical one. In five pre-registered experiments (N = 1,908) on Prolific, we tested whether and when people grant less credibility to psychiatric patients’ testimony compared to other patients and to individuals without any medical condition. We used vignette-based designs depicting both clinical and non-clinical settings to compare credibility attributions across these groups of speakers, and an incentivized prediction game to elicit beliefs about others’ attributions of credibility in these contexts. Overall, our experiments reveal that psychiatric patients’ testimony is deemed slightly less credible than the testimony of comparable non-patients in tightly matched comparisons. This surprisingly small effect was due partly to individual differences in its magnitude: participants who moralized epistemic injustice were least likely to discount psychiatric patients’ testimony, while participants who were skeptical of the phenomenon showed a stronger tendency to treat psychiatric patients as less credible than psychotypical speakers. These findings support the claim that psychiatric patients are granted reduced credibility by some audiences–in particular, by those who are least likely to view epistemic injustice as a genuine problem–a key empirical premise in the debate on whether psychiatric patients are vulnerable to epistemic injustice.

Background: Contemporary societies are rife with moral disagreement, resulting in recalcitrant disputes on matters of public policy. In the context of ongoing bioethical controversies, are uncompromising attitudes rooted in beliefs about the nature of moral truth? Methods: To answer this question, we conducted both exploratory and confirmatory studies, with both a convenience and a nationally representative sample (total N = 1501), investigating the link between people’s beliefs about moral truth (their metaethics) and their beliefs about moral value (their normative ethics).Results Across various bioethical issues (e.g., medically-assisted death, vaccine hesitancy, surrogacy, mandatory organ conscription, or genetically modified crops), consequentialist attitudes were associated with weaker beliefs in an objective moral truth. This association was not explained by domain-general reflectivity, theism, personality, normative uncertainty, or subjective knowledge. Conclusions: We find a robust link between the way people characterize prescriptive disagreements and their sensibility to consequences. In addition, both societal consensus and personal conviction contribute to objectivist beliefs, but these effects appear to be asymmetric, i.e., stronger for opposition than for approval.

The question of what makes someone the same person through time and change has long been a preoccupation of philosophers. In recent years, the question of what makes ordinary or lay people judge that someone is—or isn’t—the same person has caught the interest of experimental psychologists. These latter, empirically oriented researchers have sought to understand the cognitive processes and eliciting factors that shape ordinary people’s judgments about personal identity and the self. Still more recently, practitioners within an emerging discipline, experimental philosophical bioethics or “bioxphi”—the focus of this chapter—have adopted a similar aim and employed similar methodologies, but with two distinctive features: (a) a special concern for enhanced ecological validity in the examples and populations studied; and (b) an interest in contributing to substantive normative debates within the wider field of bioethics. Our aim in this chapter is to sample illustrative work on personal identity in bioxphi, explore how it relates to studies in psychology covering similar terrain, and draw out the implications of this work for matters of bioethical concern. In pursuing these issues, we highlight recent work in bioxphi that includes the perceived validity of advance directives following neurodegeneration, the right of psychologically altered study participants to withdraw from research, how drug addiction may cause one to be regarded by others as “a completely different person,” the effect of deep-brain stimulation on perceptions of the self, and the potential influence of moral enhancement interventions on intuitive impressions of a person’s character.

Background Toomey et al (2024) found that US participants were more likely to follow a medical treatment preference—expressed after substantial cognitive decline—of a third person rather than their own future self. This correlated with a greater tendency to see the third person as still their true self. We hypothesised that the greater epistemic access one has to one’s own true self as opposed to others might drive this difference. Methods A codebook designed to capture different kinds of evidence and reasoning was developed, and participants’ explanations for their treatment decisions in Toomey et al’s study were coded and qualitatively analysed. Results In first-person cases, participants were more likely to explain their treatment decision with reference to perceived direct access to their own true self. In contrast, in third-person cases, participants more often relied on proxies or heuristics, such as the presumption that an expressed preference is an authentic one or that preferences expressed with greater cognition tend to better reflect the true self. Conclusions These findings support the hypothesis that differential epistemic access to the true self in first- and third-person cases may drive different medical treatment decisions. Participants may be trying to follow the patient’s ‘true’ or ‘authentic’ preference in all cases, but relying on different kinds of evidence in so doing.

Jennifer Hawkins (2024) offers two cases that challenge traditional accounts of decision-making capacity, according to which respect for a medical decision turns on an individual’s cognitive capacities at the time the decision is made (Hawkins 2024; Appelbaum and Grisso 1988). In each of her described cases (involving anorexia nervosa and grief, respectively), a patient makes a decision that—although instrumentally rational at the time—does not reflect the patient’s longer-term values due to being in a particular psychological state. Importantly, this state does not impair the patient’s cognition, but rather predisposes them to make a decision that conflicts with their own broader values, beliefs, or desires.

Background Advance healthcare decision-making presumes that a prior treatment preference expressed with sufficient mental capacity (“T1 preference”) should trump a contrary preference expressed after significant cognitive decline (“T2 preference”). This assumption is much debated in normative bioethics, but little is known about lay judgments in this domain. This study investigated participants’ judgments about which preference should be followed, and whether these judgments differed depending on a first-person (deciding for one’s future self) versus third-person (deciding for a friend or stranger) perspective. Methods A vignette-based survey was conducted (N = 1445 US Americans; gender-balanced sample), in a 3 (relationship: self, best friend, stranger) × 2 (T1 preference: treat, do not treat) × 2 (T2 contrary preference: ambiguous, unambiguous) design. Results Participants were more likely to defer to the incapacitated T2 preference of a third-party, while being more likely to insist on following their own T1 capacitated preference. Further, participants were more likely to conclude that others with substantial cognitive decline were still their “true selves,” which correlated with increased deference to their T2 preferences. Conclusions These findings add to the growing evidence that lay intuitions concerning the ethical entitlement to have decisions respected are not only a function of cognition, as would be expected under many traditional bioethical accounts, but also depend on the relationship of the decision to the decision-maker’s true self.

This paper explores an emerging sub-field of both empirical bioethics and experimental philosophy, which has been called “experimental philosophical bioethics” (bioxphi). As an empirical discipline, bioxphi adopts the methods of experimental moral psychology and cognitive science; it does so to make sense of the eliciting factors and underlying cognitive processes that shape people’s moral judgments, particularly about real-world matters of bioethical concern. Yet, as a normative discipline situated within the broader field of bioethics, it also aims to contribute to substantive ethical questions about what should be done in a given context. What are some of the ways in which this aim has been pursued? In this paper, we employ a case study approach to examine and critically evaluate four strategies from the recent literature by which scholars in bioxphi have leveraged empirical data in the service of normative arguments.

Responding to recent concerns about the reliability of the published literature in psychology and other disciplines, we formed the X-Phi Replicability Project to estimate the reproducibility of experimental philosophy. Drawing on a representative sample of 40 x-phi studies published between 2003 and 2015, we enlisted 20 research teams across 8 countries to conduct a high-quality replication of each study in order to compare the results to the original published findings. We found that x-phi studies – as represented in our sample – successfully replicated about 70% of the time. We discuss possible reasons for this relatively high replication rate in the field of experimental philosophy and offer suggestions for best research practices going forward.

There is little debate regarding the acceptability of providing medical care to restore physical or mental health that has deteriorated below what is considered typical due to disease or disorder (i.e., providing “treatment”—for example, administering psychostimulant medication to sustain attention in the case of attention deficit disorder). When asked whether a healthy individual may undergo the same intervention for the purpose of enhancing their capacities (i.e., “enhancement”—for example, use of a psychostimulant as a “study drug”), people often express greater hesitation. Building on prior research in moral philosophy and cognitive science, in this work, we ask why people draw a moral distinction between treatment and enhancement. In two experiments, we provide evidence that the accessibility of health-related interventions determines their perceived descriptive or statistical normality (Experiment 1), and that gains in descriptive normality for such interventions weaken the moral distinction between treatment and enhancement (Experiment 2). In short, our findings suggest that the tendency to draw a moral distinction between treatment and enhancement is driven, in part, by assumptions about descriptive abnormality; and raise the possibility that normalizing novel biomedical interventions by promoting access could undermine people’s selective opposition toward enhancement, rendering it morally comparable to treatment.

Healthcare systems often delegate surgical consent-seeking to members of the treating team other than the surgeon (e.g., junior doctors in the UK and Australia). Yet, little is known about public attitudes toward this practice compared to emerging AI-supported options. This first large-scale empirical study examines how laypeople evaluate the validity and liability risks of using an AI-supported surgical consent system (Consent-GPT). We randomly assigned 376 UK participants (demographically representative for age, ethnicity, and gender) to evaluate identical transcripts of surgical consent interviews framed as being conducted by either Consent-GPT, a junior doctor, or the treating surgeon. Participants broadly agreed that AI-supported consent was valid (87.6% agreement), but rated it significantly lower than consent sought solely by human clinicians (treating surgeon: 97.6% agreement; junior doctor: 96.2%). Participants expressed substantially lower satisfaction with AI-supported consent compared to human-only processes (Consent-GPT: 59.5% satisfied; treating surgeon 96.8%; junior doctor: 93.1%), despite identical consent interactions (i.e., the same informational content and display format). Regarding justification to sue the hospital following a complication, participants were slightly more inclined to support legal action in response to AI-supported consent than human-only consent. However, the strongest predictor was proper risk disclosure, not the consent-seeking agent. As AI integration in healthcare accelerates, these results highlight critical considerations for implementation strategies, suggesting that a hybrid approach to consent delegation that leverages AI’s information sharing capabilities while preserving meaningful human engagement may be more acceptable to patients than an otherwise identical process with relatively less human-to-human interaction.

Recent years have seen recurring episodes of tension between proponents of freedom of speech and advocates of the disenfranchised. Recent survey research attests to the ideological division in attitudes toward free speech, whereby conservatives report greater support for free speech than progressives do. Intrigued by the question of whether “canceling” is indeed a uniquely progressive tendency, we conducted a vignette-based experiment examining judgments of offensiveness among progressives and conservatives. Contrary to the dominant portrayal of progressives and conservatives, our study documented ideological symmetry in their evaluations of offensive speech. When faced with utterances whose content matters to them, both conservatives and progressives viewed outgroup speakers as more offensive than ingroup speakers. A second contribution of this chapter is to provide a deeper understanding of the cognitive mechanism implicated in evaluating outgroup speech as more offensive than ingroup speech. Our results suggest that perception of offensiveness is mediated by ascriptions of intent: we tend to attribute negative intent to the speaker whenever we deem their utterances to be offensive, even against the explicitly stated speaker’s background attitudes.

Many bioliberals endorse broadly consequentialist frameworks in normative ethics, implying that a progressive stance on matters of bioethical controversy could stem from outcome-based reasoning. This raises an intriguing empirical prediction: encouraging outcome-based reflection could yield a shift toward bioliberal views among nonexperts as well. To evaluate this hypothesis, we identified empirical premises that underlie moral disagreements on seven divisive issues (e.g., vaccines, abortion, or genetically modified organisms). In exploratory and confirmatory experiments, we assessed whether people spontaneously engage in outcome-based reasoning by asking how their moral views change after momentarily reflecting on the underlying empirical questions. Our findings indicate that momentary reflection had no overall treatment effect on the central tendency or the dispersion in moral attitudes when compared to prereflection measures collected 1 week prior. Autoregressive models provided evidence that participants engaged in consequentialist moral reasoning, but this self-guided reflection produced neither moral “progress” (shifts in the distributions’ central tendency) nor moral “consensus” (reductions in their dispersion). These results imply that flexibility in people's search for empirical answers may limit the potential for outcome-based reflection to foster moral consensus.

Theoretical debates around the concept of self-deception revolve around identifying the conditions for a behavior to qualify as self-deception. Experiments 1 and 2 revealed that various candidate features—such as intent, belief change, and motive—are treated as sufficient, but non-necessary, conditions according to the lay concept of self-deception. This led us to ask whether there are multiple lay concepts, such that different participants endorse competing theories (the disagreement view), or whether individual participants assign partial weight to various features and consequently waver in cases of middling similarity (the conflict view). In Experiment 3, by-participant regression models uncovered that most participants additively consider multiple characteristics of the prototype of self-deception, while only a minority of participants treat a characteristic (or a combination thereof) as necessary and sufficient. In sum, by disambiguating interpersonal disagreement and intrapersonal conflict in a within-subjects design, the present experiments indicate that the lay concept may primarily exhibit a prototype structure. In closing, we suggest that future research deploying this method may help to explain why experimental research on philosophical concepts often engenders partial support for competing theories.

The psychedelic psilocybin has shown promise both as treatment for psychiatric conditions and as a means of improving well-being in healthy individuals. In some jurisdictions (e.g., Oregon, USA), psilocybin use for both purposes is or will soon be allowed and yet, public attitudes toward this shift are understudied. We asked a nationally representative sample of 795 US Americans to evaluate the moral status of psilocybin use in an appropriately licensed setting for either treatment of a psychiatric condition or well-being enhancement. Showing strong bipartisan support, participants rated the individual’s decision as morally positive in both contexts. These results can inform effective policy-making decisions around supervised psilocybin use, given robust public attitudes as elicited in the context of an innovative regulatory model. We did not explore attitudes to psilocybin use in unsupervised or non-licensed community or social settings.

Conservatives and liberals disagree sharply on matters of morality and public policy. We propose a novel account of the psychological basis of these differences. Specifically, we find that conservatives tend to emphasize the intrinsic value of actions during moral judgment, in part by mentally simulating themselves performing those actions, while liberals instead emphasize the value of the expected outcomes of the action. We then demonstrate that a structural emphasis on actions is linked to the condemnation of victimless crimes, a distinctive feature of conservative morality. Next, we find that the conservative and liberal structural approaches to moral judgment are associated with their corresponding patterns of reliance on distinct moral foundations. In addition, the structural approach uniquely predicts that conservatives will be more opposed to harm in circumstances like the well‐known trolley problem, a result which we replicate. Finally, we show that the structural approaches of conservatives and liberals are partly linked to underlying cognitive styles (intuitive versus deliberative). Collectively, these findings forge a link between two important yet previously independent lines of research in political psychology: cognitive style and moral foundations theory.

At the height of the Covid-19 pandemic, frontline medical professionals at intensive care units around the world faced gruesome decisions about how to ration life-saving medical resources. These events provided a unique lens through which to understand how the public reasons about real-world dilemmas involving trade-offs between human lives. In three studies (total N = 2298), we examined people’s moral attitudes toward triage of acute coronavirus patients, and found elevated support for utilitarian triage policies. These utilitarian tendencies did not stem from period change in moral attitudes relative to pre-pandemic levels--but rather, from the heightened realism of triage dilemmas. Participants favored utilitarian resolutions of critical care dilemmas when compared to structurally analogous, non-medical dilemmas—and such support was rooted in prosocial dispositions, including empathy and impartial beneficence. Finally, despite abundant evidence of political polarization surrounding Covid-19, moral views about critical care triage differed modestly, if at all, between liberals and conservatives. Taken together, our findings highlight people’s robust support for utilitarian measures in the face of a global public health threat, and illustrate how hypothetical scenarios in moral psychology (e.g. trolley cases) should strive for more experiential and psychological realism, otherwise their results might not generalize to real-world moral dilemmas.

This article examines whether people share the Gettier intuition (viz. that someone who has a true justified belief that p may nonetheless fail to know that p) in 24 sites, located in 23 countries (counting Hong Kong as a distinct country) and across 17 languages. We also consider the possible influence of gender and personality on this intuition with a very large sample size. Finally, we examine whether the Gettier intuition varies across people as a function of their disposition to engage in “reflective” thinking.

Philosophers have long debated whether, if determinism is true, we should hold people morally responsible for their actions since in a deterministic universe, people are arguably not the ultimate source of their actions nor could they have done otherwise if initial conditions and the laws of nature are held fixed. To reveal how non-philosophers ordinarily reason about the conditions for free will, we conducted a cross-cultural and cross-linguistic survey (N = 5,268) spanning twenty countries and sixteen languages. Overall, participants tended to ascribe moral responsibility whether the perpetrator lacked sourcehood or alternate possibilities. However, for American, European, and Middle Eastern participants, being the ultimate source of one’s actions promoted perceptions of free will and control as well as ascriptions of blame and punishment. By contrast, being the source of one’s actions was not particularly salient to Asian participants. Finally, across cultures, participants exhibiting greater cognitive reflection were more likely to view free will as incompatible with causal determinism. We discuss these findings in light of documented cultural differences in the tendency toward dispositional versus situational attributions.

In the remainder of this article, we will disarm an important motivation for epistemic contextualism and interest-relative invariantism. We will accomplish this by presenting a stringent test of whether there is a stakes effect on ordinary knowledge ascription. Having shown that, even on a stringent way of testing, stakes fail to impact ordinary knowledge ascription, we will conclude that we should take another look at classical invariantism. Here is how we will proceed. Section 1 lays out some limitations of previous research on stakes. Section 2 presents our study and concludes that there is little evidence for a substantial stakes effect. Section 3 responds to objections. The conclusion clears the way for classical invariantism.

Since at least Hume and Kant, philosophers working on the nature of aesthetic judgment have generally agreed that common sense does not treat aesthetic judgments in the same way as typical expressions of subjective preferences—rather, it endows them with intersubjective validity, the property of being right or wrong regardless of disagreement. Moreover, this apparent intersubjective validity has been taken to constitute one of the main explananda for philosophical accounts of aesthetic judgment. But is it really the case that most people spontaneously treat aesthetic judgments as having intersubjective validity? In this paper, we report the results of a cross‐cultural study with over 2,000 respondents spanning 19 countries. Despite significant geographical variations, these results suggest that most people do not treat their own aesthetic judgments as having intersubjective validity. We conclude by discussing the implications of our findings for theories of aesthetic judgment and the purpose of aesthetics in general.

This article examines whether people share the Gettier intuition (viz. that someone who has a true justified belief that p may nonetheless fail to know that p) in 24 sites, located in 23 countries (counting Hong Kong as a distinct country) and across 17 languages. We also consider the possible influence of gender and personality on this intuition with a very large sample size. Finally, we examine whether the Gettier intuition varies across people as a function of their disposition to engage in “reflective” thinking.

What should judges do when faced with immoral laws? Should they apply them without exception, since “the law is the law?” Or can exceptions be made for grossly immoral laws, such as historically, Nazi law? Surveying laypeople (N = 167) and people with some legal training (N = 141) on these matters, we find a surprisingly strong, monotonic relationship between people's subjective moral evaluation of laws and their judgments that these laws should be applied in concrete cases. This tendency is most pronounced among individuals who endorse natural law (i.e., the legal-philosophical view that immoral laws are not valid laws at all), and is attenuated when disagreement about the moral status of a law is considered reasonable. The relationship is equally strong for laypeople and for those with legal training. We situate our findings within the broader context of morality's influence on legal reasoning that experimental jurisprudence has uncovered in recent years, and consider normative implications.