Locomotion and Our Moral Notion


Locomotion and Our Moral Notion

Is there a universal moral grammar?

Debates about a human “moral sense” often spotlight the innumerable set of “taboos” that exist along cultural lines. These debates tend to confirm the common belief that culture cultivates a kind of context-dependent, moral-sentiment mélange in the psychology of its citizens which holds the group together and allows for both praise and punishment of, respectively, conformers and villains.  However, many of these rules (though there are obvious exceptions) are downright, and sometimes comically, arbitrary.

A taste:

“Do not use elevators from Friday night to Saturday night”

“Don’t wear blue in my neighborhood”

“Utter the phrase ‘excuse me’ when gas from your digestive tract is released through your mouth”

While these group-specific rules may elicit strong moral feelings in those who abide by them, it is not the rule itself that holds any moral weight (i.e. “please” is just a six-letter word); it is the fact that it is agreed upon among those who follow it that really matters, and ultimately leads to a judgment of an individual’s moral character (“that man is awfully rude…he has no manners at all!”).

This piece of the morality puzzle is most convincingly explained by the importance of upholding a tight alliance structure with your peers (see the exceptional research of Rob Kurzban at the University of Pennsylvania for details on this and many other bright ideas), though there is a multitude of other explanations for the existence of “arbitrary” or “taboo” morality, and there are surely more to come.

Yet I am more intrigued by those moral sentiments that exist cross-culturally – morals that don’t separate one group from another but bind them all together and constitute a “human moral sense.” New research in this realm by cognitive neuroscientists, psychologists, evolutionary biologists, and lawyers, has begun to unearth a “universal moral grammar” that has specific neural substrates, coherent adaptive design features, and interesting correlates in centuries and centuries of human law and philosophy.

Hold on – let me rewind one sentence. In the above list of occupational investigators, the answer to the question “which of these does not belong?” seems laughably obvious.

Trust a lawyer on the structure of morality?  Ha!

A man who never graduated from school might steal from a freight car. But a man who attends college and graduates as a lawyer might steal the whole railroad.”  – Teddy Roosevelt

Wisecracks aside, John Mikhail, a lawyer from Georgetown University Law Center, has one of the stronger theories of a universal human moral sense around, and also managed to get it published in a prominent cognitive science journal (Mikhail, 2007, see link for citation).  “Whole railroad” indeed.

Mikhail cites Noam Chomsky as a theoretical inspiration. Noam Chomsky’s “universal grammar” theory of linguistics has proven to be one of the most influential cognitive theories of the past century.  In brief, his theory pushed the view that a universal set of grammatical principles exists across languages, and implies an innate, evolved sense of what constitutes a “correct sentence,” independent of the language within which it is uttered.  Mikhail, inspired by Chomsky’s program, argues for a similar set of innate rules, though these are rules that apply to moral judgments rather than linguistic judgments; a “universal moral grammar.”  Perhaps loosely inspired by Teddy’s quip, Mikhail uses as his prime experimental example one of the more famous (and often loathed) moral dilemmas of the modern era:  “the trolley problem.”

For those not familiar with the dreaded locomotive, let me offer a brief description of a common iteration of the trolley problem, lifted straight from Mikhail:

A runaway trolley is about to run over and kill five people, but a bystander who is standing on a footbridge can shove a man in front of the train, saving the five people but killing the man. Is it permissible to shove the man?

Across cultures, genders, ages, and races, the result is essentially the same and has been replicated countless times: over 90% of respondents consider this act impermissible.

Theorists who believe humans naturally act in the interest of the many rather than the few surely can’t explain this result – we are not imbued with a natural Utilitarian sense of “the greatest good for the greatest number,” though we can be taught this idea.  Incidentally, in many of these experiments the subjects are asked to explain their responses and find themselves lost for words, referring to their decision as illogical, irrational, and simply intuitive rather than rationally justified (Mikhail, 2007).

While there are obvious issues with trolley problem experiments – the question is too sensational, it’s an unlikely if impossible situation, there is no choice to opt out and attempt to save everyone – the ubiquity of the results and the subjects’ subsequent bewilderment and incapacity to explain their choices make it a very compelling conundrum.  Furthermore, an equally persuasive result is found with what I’ll call the “switch” trolley problem:

A runaway trolley is about to run over and kill five people, but a bystander can pull a switch that will turn the trolley onto a side track, where it will kill only one person.  Is it permissible to pull the switch?

The cross-cultural, cross-gender, cross-racial result?  Around 95% consider this act permissible.

Clearly there must be a considerable difference between these two acts if one is so acceptable, the other, forbidden.  Additionally, people can’t explain why one is “better” than the other besides the basic perception that the act of pushing the man just seems worse than the act of pulling the switch.  Mikhail digs deeper.

He argues that when we analyze these problems we are actually parsing through a handful of structural properties of the stimulus (the stimulus being the trolley problem itself) that aren’t there on the surface and may not even enter into our consciousness at all.

He defines these substructures as means, ends, side effects, and prima facie wrongs (like battery).  Here’s how it breaks down for the “push the man” problem:

Means (arranged temporally)

-touching the man [committing battery]

-throwing the man [again committing battery]

-causing train to hit man [that’s battery #3]


preventing train from hitting men

Side Effects

-committing homicide

Here, three “wrongs” (batteries) lead to one “right” (safety of five men) and another wrong (death of one man).  The psychological math is not based on a “save-as-many-people-as-possible” principle, but an “avoid-committing-battery” principle. Thus, the act feels impermissible.  The subject answers accordingly (I use the word “feels” because the subject cannot rationally explain their decision; it is seemingly driven by sub-conscious mechanisms, though these need not be limited to emotions).

Here’s how it breaks down for the “switch” problem:

Means (arranged temporally)

-throwing the switch

-turning the train


preventing train from hitting men

Side Effects

-causing train to hit man [committing battery]

-committing homicide

Here, the “wrongs” occur as side effects, the means appear innocuous, and the same “rightful” end is achieved.   The act feels permissible.

Mikhail buffers these examples with more textured ones that involve detailed scenarios (i.e. throwing a switch that collapses a bridge above the tracks where one man is standing, thus saving the five – only one battery as a means this time) and finds that the impermissible/permissible responses end up somewhere in the middle.  Actually, the math works beautifully – the more acts of battery as a means, the higher percentage of “impermissible” responses.

The next step is to figure out the neurophysiological mechanisms that underlie this complex, systematic behavior.  There’s no doubt it involves both emotional and analytical brain regions.  Current research supports this idea, and points to a consistent network of activation in the anterior prefrontal cortex, medial and lateral orbitofrontal cortex, dorsolateral and ventromedial prefrontal cortex, anterior temporal lobes, and the posterior cingulate region.  This research is in its early stages, and it will be fun to watch more information emerge about the neural correlates of moral cognition.

In the end, it is the combination of three facts that make Mikhail’s universal moral grammar theory – the idea that there is an innate set of mechanisms that parse through relevant aspects of moral dilemmas – so compelling:

1)  The moral judgments that trolley problems educe are rapid, confident, and described as “gut feelings” and “intuitions.”

2)  The judgments are notably cross-demographical.

3)  The judgments are difficult to describe and thus seem to occur beneath rational consciousness and logical reasoning.

The next big question: Mikhail refers to “prima facie wrongs” (i.e. battery) that have weight in our moral decisions. What are these wrongs and how did they wedge themselves into the natural order of the human mind? Perhaps the answer will turn out to be an aesthetic one…maybe more visceral acts (such as battery) carry extra moral weight, regardless of their outcomes and side effects?  This is a mere musing, but an interesting one nonetheless.

But those are questions for another day.  Now, in all seriousness, I have to go catch a trolley.

(Hopefully the city of Philadelphia has cleared the tracks of snow…and human beings).

About the author

Sam McDougle

SAM MCDOUGLE is a Ph.D. candidate in Psychology and Neuroscience at Princeton University. His writing has appeared in Vice and The Atlantic.

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  • The first question that comes to my mind is why is the thought that the bystander himself should throw himself into the path of the trolley to save the five is not part of this equation. No wrongs there, unless of course he were suicidal and he saw the opportunity to do himself in. But then that brings into question the morality of suicide. I look forward to reading your future articles.

  • Thanks for this well presented and entertaining treatment of the question. I note that you mention the term cross culture early in the essay. I am wondering if this literal or a
    local variety – meaning everyone lives similarly but comes FROM a different culture. Having lived in vastly different cultures for periods of time in my life, I know I would be fascinated for example to hear a West African reason about the variables of the trolley question: What if the man you push does not stop the train but is dragged along with the other five? Or a West Indian ask you for more information as to the castes of each person involved and whether you have considered their karmic debts. I sometimes wish for a world where ‘all things being equal’ could actually apply. But until then, the philosophical notion that it is a society built on arbitrary rules that everyone agrees on sounds right. If you come from somewhere with a child bride through an arranged marriage, we don’t kick you out. But try to accomplish that here. I am sure that lawyers have more influence in our culture than neuroscientists as far as the ‘moral code’ goes but I hope that with more research we can all find the places that we live as humans – free from rules induced by another time and whole other circumstances.
    Did I get off subject?

  • Interesting choices that you present, Sam. I think it’s the physicality of pushing someone in front of a trolley to save the other five that induces the aversive response. Pulling the lever is so much more removed from the actual violence that ensues. So where does the famous Milgram experiment fit into the whole scheme of things? I’d like to hear your thoughts on that. Although the Milgram experiment could never be repeated because of IRB restrictions, it would have been interesting to know which parts of the brain of the pain-inducing subjects were activated. Again, any thoughts on that?

  • Interesting to think about “grammars” as poised or wedged (like that miniature half-floor in “Being John Malkovich”) or circulating in a mode between animal and rational (helps with embracing the conventional but deeply felt forms of English spelling), which might be aesthetic or visceral, leading to the equally interesting idea of somatic experience as inherently meaningful for us. Encouraging for choreographers. –Anyway, we read the trolley scene from a faculty “above” mere survival (my cat would simply see something noisy was coming down and head for the hills), but “below” the rational (reasoning on this problem is either unsuccessful, i.e. inadequate or incommensurate, or is manipulated by cultural or psychological pseudo-needs). There may indeed by a point or an experience in which converge human identity, humane behavior, and somatic gesture, such as the calm smile recommended by the Dalai Lama, or other breath- and body-shapings suggested by Yoga, sports physicians, and theatre technique.

    At least three things are going on with the battery problem in the initial version of the scene: 1) I have to shove another person to do it (not bomb him from high in air); 2) I would seem to be using him rather than regarding him as an end in himself and leaving his moral agency to its own resources (cf. Kant, somewhere); and 3) by using him I imply I could have thrown myself in front of the trolley but wasn’t up to it (Me more important than Other.

    Thanks. Had heard the trolley problem but not with questions that made it interesting.

  • Michael Gazzinga, neuroscience researcher at UC Santa Barbara, has an excellent video available on YouTube called “We Are Law”. Questions about implications of “determined behavior” and moral accountability are explored. Also the video is available at Neurolaw.

  • Sam this is a wonderful article. I look forward to reading more. Here are some thoughts on the subject.

    Battery sounds too much like the language of a lawyer and I think falls short in explanatory power by being too semantically rich. However, I think Mikhail’s explanation is penetrating and would be more apt if “battery” and “no batter” were replaced with “unpredictable” or “predictable.” Drawing on Jeff Hawkins’ work, On Intelligence, and the J.J. Gibsons’ and Edward Reed’s treatment of Affordances, I consider “battery” as the source of motivation for action or inaction unlikely. Rather, an individual perceives what might afford a course of actions in the information available in the surrounding environment. This includes one’s own person (memories, psychological state, etc. all included). Hawkins has keenly demonstrated from another angle the interrelation of pattern recognition and action. In other words, the importance of predictability in making something intelligible or actionable.

    So take Mikhail explanation and substitute “unpredictability:

    Means (arranged temporally)

    -touching the man [unpredictable (he may fight back or resist)]

    -throwing the man [unpredictable (he may fight back or resist)]

    -causing train to hit man [unpredictable (if thrown, no guarantee of accuracy)]


    Means (arranged temporally)

    -throwing the switch (effectiveness predictable)

    -turning the train (effectiveness predictable)

    “Battery” makes the act socially communicable and in this way more immediately acceptable. Scientifically, it assumes that a person imagining this scenario holds all elements controlled. It assumes that the bystander would passively let him or herself be thrown. I can think of nothing that suggests a person inserts this experimental control into their consideration of the scenario. Experience, intuition, memory, etc. would suggest the opposite is true. A person would consider seizing another and throwing them highly unpredictable and therefore unintelligible and unmotivating as a course of action.

  • Perhaps this is a moot point for what is really just a thought experiment, but I doubt that it would occur to me in the heat of the moment either to pull the lever or to push the man.

    I would probably be resigned to witnessing an unfortunate act of God and not even think of involving myself (and thus risking the danger of implication, which is a whole other moral ball game). We always like things to not be our fault.

    There are certain scenarios in which we’ve learned it is appropriate and noble to intervene, such as the event of a drowning person, but I’m not convinced that is our biological instinct – especially if both choices that would result from our intervention would lead to death and destruction.

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