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Scrap or Save? A Triune Brain Theory Account of Moral Improvement

Last month, I wrote a post called “Uncovering the Neurocognitive Systems for ‘Help This Child,’” where I suggested that understanding certain facts about our brains is not enough to get us to do the ‘right thing.’I argued that we also have to ‘outsmart’ our least rational tendencies and get ourselves to apply our knowledge to real-life problems. This month, I want to explore a different aspect of the relationship between knowledge and practical action. I want to ask, ‘What happens when researchers ground their work in a controversial scientific framework, but use it to introduce a set of ideas that could make a meaningful contribution?’ The case I have in mind is Darcia Narvaez and Jenny Vaydich’s use of Paul D. MacLean’s ‘Triune Brain Theory’ to ground work on emotional and ethical ‘expertise development.’

Jenny Vaydich
Darcia Narvaez

In their paper entitled “Moral development and behavior under the spotlight of the neurobiological sciences,” Narvaez and Vaydich set out to defend the practical applications of neurobiological and neuroscientific research for moral development and education. [1] Reviewing over a hundred studies from across these disciplines, they argue that the neurosciences can contribute to our understanding of moral development in at least three ways: (1) by shedding light on previously not-well-understood factors of moral behavior, (2) by enriching the debate regarding the relative intentionality or automatic/unconscious nature of moral responses, decision-making, and action, (3) and by examining the influence of caregiver behavior and the surrounding environment on the development of healthy brain function or, in other words, “better- or worse-equipped brains” for participating in moral life. [1] Interestingly (and quite uniquely), Narvaez and Vaydich also go on to consider the implications of these findings for the formulation of practical frameworks intended to foster ‘expertise development’ in the domain of moral functioning.

Narvaez and Vaydich propose that neurobiological research findings do indeed confirm the possibility of moral improvement. They argue that since brain structures and functions are malleable, “unless the damage is severe, there is the possibility for change.” [1]  More specifically, they argue that change can be undertaken and actualized with respect to different components of moral function and at any point in human life, although the process becomes increasingly difficult with age. [2] In addition, Narvaez outlines a set of practices, which she calls the ‘Integrative Ethical Education’ model (IEE), that can be applied in classrooms and other learning environments to help foster moral character and functioning. Among other ideas, IEE advocates for the structuring of caring relationships and supportive environments; for the engagement of ethical skills through a novice-to-expert pedagogy; for the fostering of self-authorship; and for the reintroduction of what Narvaez calls an ‘ecological’ system of support, according to which the family and surrounding community coordinate to help advance and guide the learning process. [3] Citing the Minnesota Community Voice and Character Education project as an example, Narvaez and Vaydich argue that these principles could be widely applied in education programs in schools, youth organization and other learning-oriented public institutions.

A visual representation of TBT

Problematically, Narvaez and Vaydich’s work rests on Narvaez’s own more extended project, Triune Ethic Theory (TET), which is in turn based on Paul D. MacLean’s Triune Brain Theory. [4]  MacLean’s triune brain theory suggests that the human brain comprises three basic formations, known as the reptilian complex, the paleomammalian complex (corresponding to the limbic system) and the neomammalian complex (corresponding to the neocortex), and proposes that these formations reflect the evolution of reptiles, lower mammals, and late mammals. Citing Panksepp and others [5], Narvaez argues that although the theory is “on its face simplistic in separating brain structures from one another, in fundamental ways animal and human research support MacLean’s basic theory. Accumulating research in affective neuroscience not only confirms the general thrust of MacLean’s Triune Brain Theory, but points out the critical importance of early experience in gene expression in emotional circuitry.” [6]

Unfortunately, as David Nicholson points out in his excellent post, “Snakes On a Brain, or, Why Care About Comparative Neuroanatomy (Vol.1),” Triune Brain Theory is in fact not supported by comparative neuroanatomy. Paul Patton argues that since the early 1980’s, evolutionary biologists have learned a great deal about vertebrate evolutionary history and as a result, he suggests, “it is now apparent that a simple linear hierarchy cannot adequately account for the evolution of brains or of intelligence” [7] Even more to the point, in Comparative Vertebrate Neuroanatomy, William Hodos maintains that the “extensive body of work in comparative neurobiology over the past three decades unequivocally contradicts this theory” [8]. Or, as David puts it, Triune Brain Theory is just “completely wrong.”

So what does this mean for Narvaez and Vaydich’s efforts to extend neuroscientific research into the practical domain? Do we reject their ideas as unfounded? Do we shun them for even subscribing to Triune Brain Theory? Or do try and persuade them to change their minds?

I’m wondering whether the old ‘photo-shop’ approach might not be the most efficient solution here: i.e., to put the head of the theory on a different body, and to test it further from there. What if we simply separated Narvaez and Vaydich’s practical applications from their proposed neurobiological foundations, and tried to see if they work on a different set of principles about the brain? That way, if the theoretical transplant proved successful, we could keep their more pragmatic suggestions; if not, we could still throw them out, but we would now have done so with more thorough-going reasons. This strikes me as an economical approach, especially when the ideas in question discuss less a frequently-discussed topic in neuroethics research. And we might even learn a thing or two about salvaging findings more generally. For example, we may want to use a related principle to comb through Marc Hauser’s now-compromised findings, or to carry forward ideas from other neurobiological models that have since fallen short of our scientific standards for understanding.

Can we attach the head of an old theoretical model onto a new body?
But then, I’m a philosophy student and not a neuroscientist. What do you think: does relying on Triune Brain Theory compromise even a plausible, pragmatic idea?



[1] Narvaez, D. & Vaydich, J. (2008) Moral development and behavior under the spotlight of the neurobiological sciences. Journal of Moral Education, 37(3), 289-313.

[2] Mahncke, H. W., Bronstone, A. & Merzenich, M. M. (2007) Brain plasticity and functional losses in

the aged: scientific bases for a novel intervention (San Francisco, Posit Science Corporation).

Available online at:

[3] Narvaez, D. (2010). The emotional foundations of high moral intelligence. In B. Latzko & T. Malti (Eds.). Children’s Moral Emotions and Moral Cognition: Developmental and Educational Perspectives, New Directions for Child and Adolescent Development, 129, 77-94. San Francisco: Jossey-Bass.

[4] Maclean, P.D. (1973). A triune concept of the brain and behavior. Toronto: University of Toronto Press.

[5] Panksepp, J. (2007) Neurologizing the psychology of affects: how appraisal-based constructivism

and basic emotion theory can coexist, in Perspectives in Psychological Science, 2(3), 281-296.

[6] Narvaez, D. (2009). Triune Ethics Theory and moral personality. In D. Narvaez & D.K. Lapsley (Eds.), Moral Personality, Identity and Character: An Interdisciplinary future. New York: Cambridge University Press, 136-158.

[7] Patton, Paul (2008), One World, Many Minds: Intelligence in the Animal Kingdom, in Scientific American.

[8] Comparative Vertebrate Neuroanatomy: Evolution and Adaptation, Second Edition, Eds. Ann B. Butler and William Hodos, 1996.

Want to Cite This Post?

Haas, J. (2013). Scrap or Save? A Triune Brain Theory Account of Moral Improvement. The Neuroethics Blog. Retreived on , from


  1. Thanks for introducing me to this fascinating topic. It raises some interesting – and quite general – questions for me.

    What exactly does it mean for a system of practical ethical applications "to rest" on a neuroscientific theory? If the choice of the underlying theory is in some respects interchangeable, why does the theory matter at all?

    It would seem that the practical system should flow from the theory in some substantive way (e.g. something other than as just-so stories.) Shouldn't discrediting the theory discredit the practical conclusions in some way or other?

    Then again, the Ptolemaic system of epicycles did a reasonable job of predicting planetary motion until Newton's theory of Universal Gravitation was 'shopped into the picture 🙂


  2. Thank you for your questions, Marc! I have to confess, I *love* the problem of epicycles, and I think they’re one of the best examples for illustrating how scientific theories can explain local ‘puzzles’ or problems. But I think they’re especially good at illustrating the bi-directional relationship between higher- and lower-order theories.

    Suppose, by way of a more basic example, that Jane has a small rash on her wrist. She rubs some of the ‘Grandma’s traditional’ hand cream on it and the rash goes away, and this works every time she gets the rash. Jane can know something about the relationship between the rash and the cream, namely, that the cream works really well – while still totally misunderstanding a) what really causes the rash or b) how the cream really works. So she might say something wrong like, ‘this cream works because it lowers the temperature of the rash and that makes the inflammation on my hand go away.’

    To bring the analogy back to Narvaez and Vaydich, I think their proposals might be something along the lines of ‘Grandma’s traditional’ hand cream – perhaps at the stage when Grandma first gives it to Jane, and Jane’s not even convinced that it’s going to work all that well! So I think there are probably actually two steps ahead for Narvaez and Vaydich, if they’re interested in promoting their theory:
    1) finding out if their proposals actually do work to develop moral expertise (i.e. does their proposed cream actually make the rash go away – this would be at the level of psychology ) and/or/then
    2) examining how and why, if their proposals really do work, what neuro-biological structures might underpin the original problem and its solution(s) (i.e., how does the cream work to make the rash disappear?)And here they will want to lose the Triune Brain Theory.

    Having said all of this, though, I do agree that ideally, a theory can make really strong predictions, so that some set of practical applications would follow from a theory in the substantive way you describe. But I think that, especially in the early stages of understanding a particular system (e.g. the brain right now), there’s probably a fair amount of tinkering and non-deductive trial and error when it comes to figuring out why some things go bump in the night.


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