Experimental Philosophical Bioethics
Brian D. Earp (a,b,c,d), Joanna Demaree-Cotton (a), Michael Dunn (e), Vilius Dranseika
(f,g), Jim A. C. Everett (d,h), Adam Feltz (i), Gail Geller (j), Ivar R. Hannikainen (k), Lynn
A. Jansen (l), Joshua Knobe (a,b), Julia Kolak (m), Stephen Latham (n), Adam Lerner (o),
Joshua May (p), Mark Mercurio (q), Emilian Mihailov (r,s), David Rodríguez-Arias (t),
Blanca Rodríguez López (u), Julian Savulescu (d), Mark Sheehan (e), Nina Strohminger (v),
Jeremy Sugarman (j), Kathryn Tabb (w), Kevin Tobia (a,x)
a. Department of Philosophy, Yale University, New Haven, Connecticut, USA
b. Department of Psychology, Yale University, New Haven, Connecticut, USA
c. Yale-Hastings Program in Ethics and Health Policy, The Hastings Center, Garrison, New York, USA
d. Uehiro Centre for Practical Ethics, University of Oxford, Oxford, UK
e. Ethox Centre, University of Oxford, Oxford, UK
f. Institute of Philosophy, Vilnius University, Vilnius, Lithuania
g. Faculty of Social Sciences, Arts and Humanities, Kaunas University of Technology, Kaunas, Lithuania
h. School of Psychology, University of Kent, Canterbury, UK
i. Department of Psychology, University of Oklahoma, Norman, Oklahoma, USA
j. Berman Institute of Bioethics, Johns Hopkins University, Baltimore, Maryland, USA
k. Department of Law, Pontifícia Universidade Católica do Rio de Janeiro, Rio de Janeiro, Brazil
l. Center for Ethics, Oregon Health and Sciences University, Portland, Oregon, USA
m. Department of Philosophy, The Graduate Center, CUNY, New York, New York, USA
n. Interdisciplinary Center for Bioethics, Yale University, New Haven, Connecticut, USA
o. Center for Bioethics, New York University, New York, USA
p. Department of Philosophy, University of Alabama at Birmingham, Alabama, USA
q. Program for Biomedical Ethics, Yale Medical School, Yale University, New Haven, Connecticut, USA
r. Faculty of Philosophy, University of Bucharest, Bucharest, Romania
s. Institute of Biomedical Ethics, University of Basel, Basel, Switzerland
t. Facultad de Filosofía, Universidad de Granada, Granada, Spain
u. Facultad de Filosofía, Universidad Complutense de Madrid, Madrid, Spain
v. Wharton School, University of Pennsylvania, Philadelphia, Pennsylvania, USA
w. Department of Philosophy, Bard College, New York, USA
x. Yale Law School, Yale University, New Haven, Connecticut, USA
Key words: empirical bioethics, experimental bioethics,
experimental philosophy, bioxphi
This is the authors’ copy of an published manuscript. It may be cited as:
Earp, B. D., Demaree-Cotton, J., Dunn, M., Dranseika, V., Everett, J. A. C., Feltz, A., Geller, G., Hannikainen, I.
R., Jansen, L., Knobe, J., Kolak, J., Latham, S., Lerner, A., May, J., Mercurio, M., Mihailov, E., Rodriguez-Arias,
D., Rodriguez Lopez, B., Savulescu, J., Sheehan, M., Strohminger, N., Sugarman, J., Tabb, K., & Tobia, K.
(2020). Experimental philosophical bioethics. AJOB Empirical Bioethics, 11(1), 30-33.
There is a rich tradition in bioethics of gathering empirical data to inform, supplement, or test
the implications of normative ethical analysis. To this end, bioethicists have drawn on diverse
methods, including qualitative interviews, focus groups, ethnographic studies, and opinion
surveys to advance understanding of key issues in bioethics. In so doing, they have developed
strong ties with neighboring disciplines such as anthropology, history, law, and sociology.
Collectively, these lines of research have flourished in the broader field of “empirical
bioethics” for more than 30 years (Sugarman & Sulmasy 2010).
More recently, philosophers from outside the field of bioethics have similarly employed
empirical methods—drawn primarily from psychology, the cognitive sciences, economics,
and related disciplines—to advance theoretical debates. This approach, which has come to be
called experimental philosophy (or x-phi), relies primarily on controlled experiments to
interrogate the concepts, intuitions, reasoning, implicit mental processes, and empirical
assumptions about the mind that play a role in traditional philosophical arguments (Knobe et
al. 2012). Within the moral domain, for example, experimental philosophy has begun to
contribute to long-standing debates about the nature of moral judgment and reasoning; the
sources of our moral emotions and biases; the qualities of a good person or a good life; and
the psychological basis of moral theory itself (Alfano, Loeb, & Plakias 2018).
We believe that experimental philosophical bioethics—or “bioxphi”—can similarly
contribute to bioethical scholarship and debate.
Here, we introduce this emerging discipline,
explain how it is distinct from empirical bioethics more broadly construed, and attempt to
characterize how it might advance theory and practice in this area.
On October 4th and 5th, 2019, an international, interdisciplinary workshop on “experimental
philosophical bioethics” was held at Yale University. One aim of the workshop was to produce a short
position statement outlining the distinctive features of this emerging field (the meeting schedule and
presentation abstracts showing representative new work are available at www.bioxphi.org). We are
the workshop organizers and presenters, including experimental philosophers and moral psychologists
engaged in research on bioethical topics, and (empirical) bioethicists interested in experimental
philosophy and moral psychology. Some of the material in this statement has been adapted from Earp,
B. D. (2019, August 2). Introducing bioxphi. The New Experimental Philosophy Blog, available at
What is experimental philosophical bioethics?
In simplest terms, bioxphi is experimental moral philosophy as applied to topics in bioethics.
It is thus a species of experimental philosophy. It is also a species of empirical bioethics: one
which relies primarily on controlled experiments rather than descriptive studies to make
sense of normatively charged phenomena of interest to bioethicists, with the aim of
contributing to associated substantive debates. In this way, bioxphi aims not only to establish
what people believe about matters of bioethical concern (for example, how various opinions,
attitudes, or preferences are distributed in the general population or among specific
stakeholders), but to uncover and explain why or how people arrive at certain normative
beliefs, judgments, or decisions, largely by probing the relevant situational factors and
proximate psychological mechanisms.
For example, what do ordinary people take informed consent to require—and what cognitive
processes and contextual cues contribute to judgments about whether such consent has in fact
been given (Sommers forthcoming)? How do doctors determine what constitutes a harm or
benefit when conflicting values are at stake, and what factors affect the weights they assign to
each in terms of magnitude or importance (Earp and Shaw 2017)? When policymakers decide
about fair distribution of resources, what shapes their intuitions about what justice demands?
And how do proxy decision-makers characterize respect for persons in the face of contested
intuitions about personhood, as in cases of fetuses or individuals with advanced dementia?
By attempting to empirically address these and other similar questions, the long-term goal of
bioxphi is to build cumulative, explanatory models of moral attitudes and behavior as these
relate to bioethical issues, ideally grounded in nuanced, real-life examples. Insofar as
abstract, theoretical principles or normative arguments emerge from bioxphi, they will
hopefully be enriched by having been formulated or tested in a manner that takes into account
the moral psychology of ordinary people.
Some illustrative examples
A common method in experimental philosophy is the so-called contrastive vignette technique
(CVT), wherein certain stimuli or aspects of a situation are systematically manipulated to
identify the particular factors and processes that shape moral concepts, intuitions, judgments,
and decisions (Reiner 2019). Here, we share some illustrative examples of this technique in
bioxphi, leaving questions about potential normative implications to the following section.
Consider an early bioxphi study by Jansen, Fogel, and Brubaker (2013). They asked a group
of physicians to judge the intentions of a doctor who, depending on the experimental
condition, was described as bringing about either a harmful or a helpful patient outcome as a
consequence of enrolling them in a pharmaceutical trial. Consistent with classic work on the
“side-effect effect” in experimental philosophy (Knobe 2003), participants judged the doctor
to have behaved more intentionally with respect to the outcome when patients were harmed
than when they were helped as a side-effect of participating in the study.
More recently, Earp and colleagues (2019) used the CVT to study folk intuitions about
perceived discontinuity in personal identity as a consequence of addiction. In this study, the
characteristics of an agent and their drug of addiction were systematically manipulated across
a set of vignettes. Participants were then asked to judge the extent to which the addicted agent
was the “same person as” the agent prior to addiction. The researchers found that becoming
addicted to a drug can lead to the strong impression that one is not the same person as before,
and that this perception may be driven by perceived negative changes in the drug user’s
moral character. This work builds on previous studies exploring the intuitive basis for
judgments about altered identity in the context of neurodegeneration (Strohminger &
Nichols, 2014; Tobia, 2016). Such studies in turn may be relevant to debates about, for
example, the validity of advance directives.
As a final example, Mihailov, Hannikainen and Rodríguez López (under review) described a
series of agents who take cognitive enhancing medications while engaged in various
competitive and non-competitive activities. Through the combined effects of effort and
enhancement, each agent succeeds in their activity. Even though procedural fairness was
stipulated across all cases, only participants who scored high on a baseline psychological
measure of personal investment in fairness attributed the agent’s success more to the “pill”
than to “skill” and judged the enhancement to be impermissible. These findings might
suggest that concerns about fairness in the cognitive enhancement debate could depend in
part upon the psychological attributes of the debater.
Given that bioxophi—in contrast to, say, moral psychology—is situated within bioethics, one
might ask whether or how the descriptive empirical evidence generated by bioxphi studies
can help in drawing normative moral conclusions. Within the broader field of empirical
bioethics, a large number of complex methods have been employed toward this end. These
include normative-empirical reflective equilibrium, grounded moral analysis, reflexive
balancing (Davies, Ives, and Dunn 2015) and practical reflective equilibrium (Savulescu,
Kahane and Gyngell 2019).
Such strategies often take the context-specific moral judgments of stakeholders at face value
to shape normative arguments or inform the future development of practice. A different
approach, based on insights from experimental philosophy, is to trace the underlying sources
of such moral judgments, treating them as objects of investigation in their own right.
Depending on what is discovered about the situational factors or psychological processes
involved in producing such judgments, their role in a given normative argument might be
affirmed or called into question.
In debates about palliative care for terminally ill patients, for example, it is sometimes argued
that a high dose of pain medication that will foreseeably cause the patient’s death may
nevertheless permissibly be administered if the doctor’s intention is to relieve suffering, but
not if their intention is to cause death. Yet if judgments about what a doctor actually intended
may be influenced by such factors as whether their actions led to a positive or negative
outcome—as the study by Jansen et al. (2013) described earlier seems to suggest—this may
require fresh thinking about how to determine whether such actions are indeed permissible on
As another example, consider that a recurring objection to cognitive bioenhancement is that it
is, in one way or another, unfair. In the previously mentioned study by Mihailov et al. (under
review), it turned out that judgments about fairness were strongly influenced by participants’
individual psychological attributes, even when procedural fairness was explicitly not at issue
in the vignettes used. One might think, then, that the normative force of such judgments, at
least when procedural fairness has been accounted for, may deserve a more skeptical look in
the context of objections to cognitive bioenhancement.
In essence, the approach we are describing asks whether a given influence debunks or
vindicates the relevant judgments, or their role in a normative argument (Kumar & May
2019). Consider the following simplified schema for such debunking (or vindicating):
1. Moral judgment M is mainly influenced by factor/process F/P. [empirical
2. F/P is an unreliable (reliable) or morally irrelevant (relevant) factor/process.
3. So, moral judgment M is unjustified (vindicated/not defeated).
Such a schema makes clear that a normative premise is still required to reach a normative
conclusion. Yet experimental results derived from bioxphi studies, we claim, can provide
crucial support for the empirical premise.
A flourishing bioxphi movement envisages empirically-oriented philosophers and ethicists
and normatively-minded clinicians and cognitive scientists coming together to study deep
questions in bioethics. This is at heart, then, a collaborative project, which aims to integrate
experimental study and normative analysis. In particular, the experimental approach can
illuminate factors and processes underlying real-life bioethical judgments, which can in turn
be assessed for their normative significance. By helping us understand why and how people
make certain moral judgments, bioxphi aims to encourage a new perspective on traditional
bioethical questions, affecting how these questions are studied, taught, and perhaps
ultimately, addressed in public policy.
Alfano, M., Loeb, D. and Plakias, A. (2018). Experimental moral philosophy. In E. N. Zalta
(ed.)., The Stanford Encyclopedia of Philosophy.
Davies, R., Ives, J., & Dunn, M. (2015). A systematic review of empirical bioethics
methodologies. BMC Medical Ethics, 16(15), 1-13.
Earp, B. D., Skorburg, J. A., Everett, J. A., & Savulescu, J. (2019). Addiction, identity,
morality. AJOB Empirical Bioethics, 10(2), 136-153.
Earp, B. D., & Shaw, D. M. (2017). Cultural bias in American medicine: the case of infant
male circumcision. Journal of Pediatric Ethics, 1(1), 8-26.
Jansen, L. A., Fogel, J. S., & Brubaker, M. (2013). Experimental philosophy, clinical
intentions, and evaluative judgment. Cambridge Quarterly of Healthcare Ethics, 22(2), 126-
Knobe, J. (2003). Intentional action and side-effects in ordinary language. Analysis 63, 190-
Knobe, J., Buckwalter, W., Nichols, S., Robbins, P., Sarkissian, H., & Sommers, T. (2012).
Experimental philosophy. Annual Review of Psychology, 63, 81-99.
Kumar, V., & May, J. (2019). How to debunk moral beliefs. In J. Suikkanen & A. Kauppinen
(eds.), Methodology and Moral Philosophy (pp. 25–48). New York: Routledge.
Reiner, P. B. (2019). Experimental neuroethics. In S. Nagel (ed.) Shaping Children (pp. 75-
83), Cham, Switzerland: Springer.
Savulescu, J., Kahane, G., & Gyngell, C. (2019). From public preferences to ethical policy.
Nature Human Behaviour, published online, August 26, 1-3. https://doi.org/10.1038/s41562-
Sommers, R. (forthcoming). Commonsense consent. Yale Law Journal, forthcoming.
Available at http://dx.doi.org/10.2139/ssrn.2761801
Strohminger, N., & Nichols, S. (2015). Neurodegeneration and identity. Psychological
Science, 26(9), 1469-1479.
Sugarman, J., & Sulmasy, D. P. (Eds.). (2010). Methods in Medical Ethics. Georgetown:
Georgetown University Press.
Tobia, K. P. (2016). Personal identity, direction of change, and neuroethics. Neuroethics,