lab studies moral judgment and decision-making, primarily using
behavioral experiments and functional neuroimaging (fMRI). The
goal of our research is to understand how moral judgments are
shaped by automatic processes (such as emotional “gut reactions”)
and controlled cognitive processes (such as reasoning and
self-control). Much of our work is aimed at understanding
these automatic and controlled processes in more detailed functional
terms. Recent work examines related phenomena such as cooperation,
punishment, and belief in God.
Our research indicates that there is no dedicated
“moral sense” or “moral faculty.” Instead, moral judgment depends on
the functional integration of multiple cognitive systems, none of
which appears to be specifically dedicated to moral judgment.
In light of this, our research strategy is not to isolate and
characterize the moral parts of the brain, but rather to understand
how moral judgments arise from the coordinated interaction of
various domain-general cognitive systems. These include systems that
enable reasoning and cognitive control, the representation of value
and the motivation of its pursuit, the simulation of distal events
using sensory imagery, and the representation of structured
Much of our research is motivated by normative
philosophical questions and practical questions about how we can
solve the moral problems that divide us. My book (Moral
Tribes: Emotion, Reason, and the Gap Between Us and Them)
addresses these issues, applying the lessons of this new science to
old philosophical questions and current social problems.
Emotion and Reason in Moral Judgment
such as Plato and Kant conceived of mature moral judgment as a
rational enterprise, as a matter of appreciating abstract reasons
that in themselves provide direction and motivation. In contrast
to these philosophers, "sentimentalist" philosophers such as David
Hume and Adam Smith argued that emotions are the primary basis for
moral judgment. I believe that emotion and reason both play
critical roles in moral judgment and that their respective
influences have been widely misunderstood.
More specifically, I have proposed a "dual-process"
theory of moral judgment according to which characteristically
deontological moral judgments (judgments associated with concerns
for "rights" and "duties") are driven by automatic emotional
responses, while characteristically utilitarian or
consequentialist moral judgments (judgments aimed at promoting the
"greater good") are driven by more controlled cognitive
processes. If I'm right, the tension between deontological
and consequentialist moral philosophies reflects an underlying
tension between dissociable systems in the brain. Many of my
experiments employ moral dilemmas, adapted from the philosophical
literature, that are designed to exploit this tension and reveal
its psychological and neural underpinnings.
Moral Dilemmas and the "Trolley Problem"
main line of experimental research began as an attempt to
understand the "Trolley Problem," which was originally posed by
the philosophers Philippa
Foot and Judith Jarvis
First, we have the switch dilemma: A
runaway trolley is hurtling down the tracks toward five people who
will be killed if it proceeds on its present course. You can save
these five people by diverting the trolley onto a different set of
tracks, one that has only one person on it, but if you do this
that person will be killed. Is it morally permissible to turn the
trolley and thus prevent five deaths at the cost of
one? Most people say "Yes."
Then we have the footbridge
dilemma: Once again, the trolley is headed for five people.
You are standing next to a large man on a footbridge spanning the
tracks. The only way to save the five people is to push this man
off the footbridge and into the path of the trolley. Is that
morally permissible? Most people say "No."
These two cases create a puzzle for moral
philosophers: What makes it okay to sacrifice one person to
save five others in the switch
case but not in the footbridge
case? There is also a psychological puzzle here: How
does everyone know (or "know") that it's okay to turn the trolley
but not okay to push the man off the footbridge?
According to my dual-process theory of moral
judgment, our differing responses to these two dilemmas reflect
the operations of at least two distinct psychological/neural
systems. On the one hand, there is a system that tends to
think about both of these problems in utilitarian terms:
Better to save as many lives as possible. The operations of
this system are more controlled, perhaps more reasoned, and tend
to be relatively unemotional. This system appears to depend
on the dorsolateral prefrontal cortex, a part of the brain
associated with "cognitive control" and reasoning.
On the other hand, there is a different neural system that
responds very differently to these two dilemmas. This system
typically responds with a relatively strong, negative emotional
response to the action in the footbridge
dilemma, but not to the action in the switch dilemma. When this more
emotional system is engaged, its responses tend to dominate
people's judgments, explaining why people tend to make utilitarian
judgments in response to the switch
dilemma, but not in response to the footbridge dilemma.
If you make the utilitarian judgment sufficiently
attractive, you can elicit a prolonged competition between these
two systems. Consider the crying
baby dilemma: It's war time, and you are hiding in
a basement with several other people. The enemy soldiers are
outside. Your baby starts to cry loudly, and if nothing is done
the soldiers will find you and kill you, your baby, and everyone
else in the basement. The only way to prevent this from happening
is to cover your baby's mouth, but if you do this the baby will
smother to death. Is it morally permissible to do this?
to the dual-process theory, this dilemma is difficult because it,
like the footbridge
dilemma elicits a strong negative emotional response ("Don't kill the
baby!"), while at the same time eliciting a
comparably compelling utilitarian response from the other system
("But if you don't kill the baby, everyone dies.") Difficult
dilemmas like this one tend to elicit increased activity in the
anterior cingulate cortex, a brain region associated with
"response conflict." And when people make utilitarian judgments in
response to these difficult dilemmas, they exhibit increased
activity in anterior regions of the dorsolateral prefrontal
S.M., Greene, J.D. (submitted) 'Man bites dog' versus 'dog
bites man': The representation of structured thoughts in left-mid
superior temporal cortex.
M.A., Stewart, L.E., Greene, J.D. (submitted) Is life worth
living?: Measuring net happiness and its misperception.
Abe, N., Greene, J.D. (2014) Response to anticipated reward in the
nucleus accumbens predicts behavior in an independent test of
honesty.Journal of Neuroscience. 34(32),
Greene, J.D. (2014) Beyond point-and-shoot morality: Why
cognitive (neuro)science matters for ethics. Ethics,
124(4), 695-726. PDF
Shariff, A.F., Greene, J.D., Karremans, J.C., Luguri, J.,
Clark, C.J., Schooler, J.W., Baumeister, R.F., Vohs, K.D. (2014
ePub) Free will and punishment: A mechanistic view of human nature
reduces retribution. Psychological Science.PDF
Shenhav, A., Greene, J.D. (2014) Integrative moral judgment:
Dissociating the roles of the amygdala and the ventromedial
prefrontal cortex. Journal of Neuroscience. 34(13),
*Rand, D.G., *Peysakhovich, A., Kraft-Todd, G.T., Newman, G.E.,
Wurzbacher, O., Nowak, M.A., Greene, J.D. (2014) Social heuristics
shape intuitive cooperation. Nature Communications. Doi:
J.M., Bruni, T., Greene, J.D. (2013 ePub) Are "counter-intuitive"
deontological judgments really counter-intuitive?: An empirical
reply to Kahane et al. (2012). Social, Cognitive, and Affective
Rand, D.G., *Greene, J.D., *Nowak, M.A. (2012) Spontaneous
giving and calculated greed. Nature, 489, 427-430. PDF
Amit, E., and Greene, J.D. (2012) You see, the ends don't justify
the means: Visual imagery and moral judgment. Psychological Science, 23(8),
861-868. PDF Baron, J.,
Ritov, I., and Greene, J.D. (2011 ePub, 2013) The duty to support
nationalistic policies. Journal
of Behavioral Decision Making, 26(2) 128-138.CV-5-19-13PDF
Cushman, F.A., Murray, D., Gordon-McKeon, S., Wharton, S., Greene,
J.D. (2011 ePub, 2012) Judgment before principle: Engagement of
the frontoparietal control network in condemning harms of
omission. Social, Cognitive,
and Affective Neuroscience, 7(8) 888-895. CV-5-19-13PDF
Cushman, F.A. and Greene, J.D. (2012) Finding faults: How
moral dilemmas illuminate cognitive structure. Social Neuroscience, 7(3-4),
*Shenhav, A.S., *Rand, D.G., Greene, J.D. (2011 ePub, 2012) Divine
intuition: Cognitive style influences belief in God. Journal of Experimental Psychology:
General, 141(3) 423-8. PDF
Paxton, J.M., Ungar, L., Greene, J.D., (2011 ePub, 2012)
Reflection and reasoning in moral judgment. Cognitive Science, 36(1) 163-177.
Shen, F.X., Hoffman, M.B., Jones, O.D., Greene, J.D., Marois, R.
(2011) Sorting guilty minds. New
York University Law Review, Vol. 80. PDF at SSRN
Greene, J.D. (2011) Morality and emotion: A tasting menu. Emotion Review, 3(3) 1-3.
(Editor’s introduction to special issue) PDF
Shenhav, A.S., Greene, J.D. (2010). Moral judgments recruit
domain-general valuation mechanisms to integrate representations
of probability and magnitude. Neuron,
67, 667-677. PDF
Bazerman, M.H. and Greene, J.D. (2010). In favor of clear
thinking: Incorporating moral rules into wise cost-benefit
analysis. Perspectives on
Psychological Science, 5(2), 209-212. PDF
Paxton, J.M., Greene, J.D., (2010) Moral reasoning: Hints
and allegations. Topics in
Cognitive Science, 2(3), 511-527. PDF
Paxton, J.M. (2009) Patterns of neural activity associated with
honest and dishonest moral decisions. Proceedings of the National Academy of Sciences USA,
Vol. 106, No. 30, 12506-12511. PDF
Paharia, N., Kassam, K.S., Greene, J.D., Bazerman, M.H. (2009)
Dirty work, clean hands: the moral psychology of indirect
Behavior and Human Decision Processes, 109, 134-141.PDF
J.D., Cushman, F.A., Stewart. L.E., Lowenberg, K., Nystrom, L.E.,
and Cohen, J.D. (2009) Pushing moral buttons: The interaction
between personal force and intention in moral judgment. Cognition, Vol. 111 (3),
Greene, J.D. (2009) Dual-process morality and the
personal/impersonal distinction: A reply to McGuire, Langdon,
Coltheart, and Mackenzie. Journal
Experimental Social Psychology, Vol. 45 (3), 581-584. PDF
Greene, J.D., Morelli, S.A., Lowenberg, K., Nystrom, L.E., Cohen,
J.D. (2008) Cognitive load selectively interferes with utilitarian
moral judgment. Cognition,
Vol. 107, 1144-1154.PDFSupplementary Materials
Greene, J.D. (2007) Why are VMPFC patients more
utilitarian?: A dual-process theory of moral judgment
explains. Trends in
Cognitive Sciences. Vol 11, No. 8, 322-323. PDF
Greene, J. D. , Cohen J. D. (2004) For the law, neuroscience
changes nothing and everything. Philosophical
Transactions of the Royal Society of London B, (Special
Issue on Law and the Brain), 359, 1775-17785. PDF Greene,
J.D., Nystrom, L.E., Engell, A.D., Darley, J.M., Cohen, J.D.
(2004) The neural bases of cognitive conflict and control in
moral judgment. Neuron,
Vol. 44, 389-400. PDF Greene, J.D.
(2003) From neural "is" to moral "ought": what are the moral
implications of neuroscientific moral psychology? Nature Reviews Neuroscience,
Vol. 4, 847-850. PDF Greene, J.
and Haidt, J. (2002) How (and where) does moral judgment
work? Trends in Cognitive
Sciences, 6(12), 517-523. PDF Greene,
J.D., Sommerville, R.B., Nystrom, L.E., Darley, J.M., & Cohen,
J.D. (2001). An fMRI investigation of emotional engagement
in moral Judgment. Science,
Vol. 293, 2105-2108. PDF Greene,
J.D., Baron, J. (2001). Intuitions about declining marginal
utility. Journal of
Behavioral Decision Making, 14, 243-255. PDF Baron, J.,
Greene, J.D. (1996). Determinants of insensitivity to quantity in
valuation of public goods. Journal
Experimental Psychology: Applied, 2, 107-125. PDF
Greene, J.D. (in press) The cognitive neuroscience of moral
judgment and decision-making, in The Cognitive Neurosciences V, M.S. Gazzaniga,
Ed. MIT Press, Cambridge, MA.
Amit, E., Gottlieb, S., Greene, J.D., (in press). Visual vs. verbal
thinking and dual-process moral cognition, in Dual-process
Theories of the Social Mind, J. Sherman, B. Gawronski, Y.
Trope, Eds. Guilford Press.
Cushman, F.A., and Greene, J.D. (2012) The philosopher in the
theater, in The Social psychology of morality: Exploring the causes
of good and evil, M. Mikulincer, P.R. Shaver, Eds. APA Press.
D. (2011) Social neuroscience and the soul's last stand, in
Social Neuroscience: Toward
Understanding the Underpinnings of the Social Mind, A.
Todorov, S. Fiske, and D. Prentice, Eds. Oxford University
Press, New York. PDF
Cushman, F., Young, L., Greene, J.D. (2010) Our mutli-system
moral psychology: Towards a consensus view, in The Oxford Handbook of Moral
Psychology, J. Doris, G. Harman, S. Nichols, J. Prinz, W.
Sinnott-Armstrong, S. Stich, Eds. Oxford University Press. PDF
Greene, J.D. (2009) The cognitive neuroscience of moral judgment, in
The Cognitive Neurosciences IV,
M.S. Gazzaniga, Ed. MIT Press, Cambridge, MA. PDF
(2009) Fruit flies of the moral mind, in What's Next: Dispatches from the
Future of Science, M. Brockman, Ed., Vintage, New York.
Greene, J. D. (2007). The secret joke of Kant's soul, in Moral Psychology, Vol. 3: The
Neuroscience of Morality: Emotion, Disease, and Development, W.
Sinnott-Armstrong, Ed., MIT Press, Cambridge, MA. PDF
S.M., Botvinick, M.M., Yeung, N., Greene, J.D., Cohen, J.D.
(2007). Conflict monitoring in conflict-emotion competition, in Handbook of Emotion Regulation,
J.J. Gross Ed., Guilford Press, New York. Greene, J.
D. , Cohen J. D. (2006), For the law, neuroscience changes nothing
and everything, in Law and the
Brain, S. Zeki and O. Goodenough, Eds., Oxford University
Press, New York. PDF
(journal version) Greene, J.
(2005). Emotion and cognition in moral judgment: evidence from
neuroimaging, in Neurobiology
of Human Values, J.P. Changeux, A.R. Damasio, W. Singer,
and Y. Christen, Eds., Springer-Verlag, Berlin. Greene, J.
(2005). Cognitive neuroscience and the structure of the moral
mind, in The Innate Mind:
Structure and Contents, S. Laurence, P. Carruthers,. and
S. Stich. Eds., Oxford University Press, New York. PDF
Doctoral thesis: Greene, J. D.
(2002). The Terrible, Horrible, No Good, Very Bad Truth About
Morality and What To Do About It. Department of Philosophy,
Princeton University (advised by David Lewis and Gilbert Harman;
available by request).