April 22, 2010

Even bugs have values! – The biological foundation of human ethics.

Posted in Values and the pfc tagged , , , at 3:44 pm by Jeremy

Oh God said to Abraham, “Kill me a son”
Abe says, “Man, you must be puttin’ me on”

Bob Dylan stated it clearer than most: the irresolvable conflicts that can arise when different value systems clash.  In one of the most memorable scenes of the Old Testament, God wants to test Abraham’s faith, so he tells him to sacrifice his son, Isaac.  Abraham is faced with a clash of values: his paternal bond to the son he loves versus his commitment to an invisible, all-powerful authority.  And even to this day, that conflict resounds.  As Nobel laureate Steven Weinberg notes in a 2008 article in the New York Review of Books, “even someone who believes in God can feel that Abraham in the Old Testament was wrong to obey God in agreeing to sacrifice Isaac.”[1]

Abraham sacrificing Isaac: a fundamental clash of values.

Where do these different values systems come from?  Why do they conflict with each other?  And how do they affect the way we live our lives every day?  In a series of blog posts, I’m going to explore these questions.  We’ll see the crucial role that the prefrontal cortex (pfc) plays in constructing our values.  And if you follow me to the end, perhaps we can arrive together at some ideas about how we might evolve our value system to respond to major 21st century issues such as our ever-accelerating effects on the global environment.

Oftentimes, when people talk about values, they begin with some great externality such as God.  Alternatively, more recently, many evolutionary psychologists note the fact that homo sapiens has spent 99% of its career in bands of hunter-gatherers, and focus accordingly on the core values that evolved in that environment.  I agree in general with the approach of the evolutionary psychologists, but I think if you really want to understand values, you have to go back even further.  Values begin in the body.  Values were embodied before we evolved the capacity to talk about them.  And, in fact, I’d go back even further than that.  Back to the very earliest, primeval times on the earth.  Back to the days, over a billion years ago, when the only living things around were single-celled organisms.

What, you might ask, does a bacterium wallowing around in a primordial ooze have to do with values?  Stuart Kauffman explains it well:

Consider then a bacterium swimming up the glucose gradient.  The biological function that is being fulfilled is obtaining food… Here, the bacterium detects a local glucose gradient, which is a sign of more glucose in some direction.  By altering its behavior and swimming up the gradient, the bacterium is interpreting the sign… Thus meaning has entered the universe: the local glucose gradient is a sign that means glucose is – probably – nearby.  Because natural selection has assembled the propagating organization of structures and processes that lead to swimming up the glucose gradient for good selective reasons, glucose has value to the bacterium.[2]

A pseudomonas bacterium: even it has values.

OK, I hear you say, but that’s cheating.  Maybe the glucose has value to the bacterium, but that’s not the same as our values… we’ve advanced well beyond that.  Yes, we certainly have.  For one thing, we have brains with complex neurological structures that no bacterium can ever imagine.  But our brains evolved in order to help the other parts of our body do their jobs more efficiently.  Our bodies are, after all, composed of about ten trillion cells, and each of these cells, just like that bacterium, needs nutrition in order to live its life to the full and keep us healthy.  So it’s not surprising that neuroscientist Antonio Damasio, one of today’s leading theoreticians on human consciousness, sees an inextricable link between amoebas and us:

A simple organism made up of one single cell, say, an amoeba, is not just alive but bent on staying alive.  Being a brainless and mindless creature, an amoeba does not know of its own organism’s intention in the sense that we know of our equivalent intentions.  But the form of an intention is there, nonetheless, expressed by the manner in which the little creature manages to keep the chemical profile of its internal milieu in balance while around it, in the environment external to it, all hell may be breaking loose…

What I am driving at is that the urge to stay alive is not a modern development.  It is not a property of humans alone.  In some fashion or other, from simple to complex, most living organisms exhibit it.  What does vary is the degree to which organisms know about that urge.  Few do.  But the urge is still there whether organisms know of it or not.  Thanks to consciousness, humans are keenly aware of it…[3]

Between the two extremes of self-aware humans and amoebas lie the millions of species of multi-celled organisms that inhabit our world.  For many of these species – the animals – a nervous system evolved to create a bi-directional feedback system connecting the brain with the other billions of cells that make up the animal’s body. In a 2009 paper, physiologist Michel Cabanac traces the evolution of the nervous system from an elemental reflex-oriented mechanism to a more sophisticated one where a basic form of consciousness appears.[4] Cabanac sees a major transition occurring between the class of animals that nowadays includes amphibians such as frogs and toads and the class that led to other animals such as birds, turtles, snakes and mammals.  For amphibians, a basic feeling will elicit a hard-wired, instinctual response.  A frog feels hunger and sees a rapid movement in front – its tongue shoots out to catch a fly.   But for more evolutionarily sophisticated animals, responses go beyond these basic steps.  A far more complex series of primary emotions, such as anger or fear, can drive the animal’s response.

A frog: Cabanac contrasts its hard-wired instinct to creatures with basic emotions.

With the evolution of humans, something unique happens to those primary emotions.  The symbolizing power of the human prefrontal cortex enables us to experience a range of emotions that go way beyond simple things such as anger or fear.  Our complex social awareness leads us into areas such as pride, shame, and all kinds of intangible emotions far too nuanced to even have a name attached to them.[5] And finally, we humans have awareness of these emotions.  So, whereas another animal can feel anger, only a human has the ability to look at herself and say “I feel angry.”  See the diagram below for a visualization of these differences (click on it for a bigger version).

Now, we’re getting close to the point where we can begin to understand how our values arise out of those embodied emotions that evolved over hundreds of millions of years.  In an interesting 2007 paper, psychologist Darcia Narvaez has traced what she calls the “neurobiological roots of our multiple moralities.”[6] She takes as her evolutionary framework the model devised by renowned neuroscientist P.D. Maclean called the “triune brain theory,” which views the human brain as comprising three layers: an evolutionarily ancient “reptilian” brain enveloped by an “early mammal” brain, which is in turn overlaid by the more recent neocortex (which incorporates the pfc.)

In Narvaez’s view, each of these three layers drives different sets of ethical values, leading to our current human condition where “three distinctive moral systems, rooted in the basic emotional systems, propel human moral action on an individual and group level.”  In summary, here’s the gist of her three systems:

  • The “Reptilian brain” produces a Security Ethic incorporating physical survival, fear, anger, basic sexuality.
  • The “Early Mammalian brain” produces an Engagement Ethic incorporating feelings of intimacy, care-giving, loneliness and sorrow.
  • The Neocortex produces an Ethic of Imagination incorporating logic, reason, consideration of alternative actions and “perspective taking.”

So now we’ve reached the starting point.  We don’t necessarily have to accept the exact categorizations that Narvaez offers, but the general framework is what’s most important.  We can now begin to see how God telling Abraham to sacrifice Isaac might come from Narvaez’s Ethic of Imagination whereas Abraham’s reluctance – “you must be puttin’ me on” – arose from his paternal instinct that was part of his Engagement Ethic.

In the next posts, I’m going to dig deeper into some of the findings of evolutionary psychology, which examines how these different systems converged in the minds of our paleolithic ancestors to create a set of hunter-gatherer values.  And as we move along humanity’s cognitive career, we’ll see how the different stages of social development led to the flowering of different sets of values, all of which interweave through our current system of thought.  Yes, we have come a long way from that primordial ooze.


[1] Weinberg, S. (2008). “Without God.” New York Review of Books, LV(14: September 25, 2008), 73-76.

[2] Kauffman, S. (2008). Reinventing the Sacred: A New View of Science, Reason, and Religion, New York: Basic Books, 86-7.

[3] Damasio, A. (1999). The Feeling of What Happens: Body and Emotion in the Making of Consciousness, New York: Harcourt Inc, 136-7.

[4] Cabanac, M., Cabanac, A. J., and Parent, A. (2009). “The emergence of consciousness in phylogeny.” Behavioural Brain Research(198: 2009), 267-272.

[5] Many ethologists, such as Sue Savage-Rumbaugh who has extensively studied great apes such as chimpanzees and bonobos, also claim most of these complex emotions for advanced primates.

[6] Narvaez, D. (2007). “Triune ethics: The neurobiological roots of our multiple moralities.” New Ideas in Psychology, 26(1), 95-119.

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1 Comment »

  1. Leah Goins said,

    If I had a dime for each time I came to jeremylent.wordpress.com… Superb read!


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