Tuesday, February 24

The Biological Evolution of Morals

Ruse and Wilson claim that culture is shaped by biology and that “a tight and formal connection can be made between biological evolution and cultural change” (Ruse & Wilson, 184). They provide incest as an example of this process. The biological explanation for our repugnance towards it is that because inbreeding produces lower genetic fitness, natural selection has produced a juvenile sensitive period, where children (0-6 years of age) that are consistently within close proximity to one another develop an inability “to from strong sexual bonds during adolescence or later” (R&W, 184). This aversion we feel towards incest once we’ve reached sexual maturity has given birth to cultural norms that dictate such behavior is morally reprehensible.

This would suggest, as Ruse and Wilson advocate, that moral norms are a product of the evolution of our biological nature, or in the very least that they are tightly connected. However, what about cultural norms that are contrary to our biology? There are two major examples that spring to mind: methods of population control and modern medicine.

Humans are unquestioningly biologically programmed to reproduce. However, given our problems with population, it is possible that many people have decided to forgo their natural urge to procreate in order to help curb overpopulation. An example of this being a cultural norm rather than simply an individual choice is China’s one child policy. Does this imply that because I feel the morally correct action is to not reproduce, I am actually acting immorally because it is contrary to my biological nature? Perhaps I have that moral inclination because I am biologically programmed to; in that case the only way that moral inclination could biologically evolve is if those who obtained it passed on to others in their genes, which is absurd.

Modern medicine is another great example. There is a prevalent cultural norm that saving the lives of others is a morally good action. However, it is also clear that many of the ailments modern medicine treats are a result of biology. For example, if I develop a deadly form of cancer because I had a specific gene that predisposed me to cancer, it is doubtless in my ‘biological makeup’ to die from it. Does that mean I shouldn’t seek treatment that could save my life? I’m not sure how this issue can be addressed from the stance that Ruse and Wilson take on morality and biology.

There are numerous other examples that are culturally normative and biologically opposed (i.e. ritual suicide), but I won’t delve into them here. My point is that if biological evolution and cultural change is so tightly related, as Ruse and Wilson claim they are, how do we account for the glaring anomalies? Any ideas?

(Works Cited: Ruse, Michael and Wilson, Edward. "Moral Philosophy as Applied Science". 1986: pg. 173-192)


  1. Though I don’t agree with the hard line approach of Ruse and Wilson, I do believe that some cultural norms are shaped by biology but humans being complex beings (to say the least) overgeneralization of some specific cases would make the claim less plausible.

    In the incest example they gave to make the claim, incest is a taboo in almost all society because of the possible genetic abnormality of the offspring but Is it a taboo because of the possible genetic outcome? Is it alright in societies to have platonic relations among siblings? The answer to the 2nd question is a resounding no, it is still considered a taboo. I think it would still be considered a taboo assuming the platonic relation will never lead to sexual because there are much larger untapped moral issues than just biology or genetics. Thus biology is just one but not the only factor.

    I agree with your statement that human like most animal species are programmed to procreate (probably as a species preservation mechanism). I also agree that it is absurd to say that the decision to have an “x” number of kids (assuming it is based on moral grounds) could biologically evolve and the genes could be passed on. But when a mother/parent decide on number of child, Is it based on moral stance to curb overpopulation? I don’t think so because even a rational active humanitarian would have a child based upon want, financial situations (for number of kids) and other reasons and not on global issues (overpopulation), as important as it may be for her (of course there are exceptions). Also, irrespective of urge to procreate it is limited to an extent by biology; age, physical limitations to undergo numerous pregnancies etc. Isn’t China’s one child policy more of a legislative rather than a cultural norm?

  2. While China's one child policy is a legislative norm, I think the legislative policy makes it culturally unacceptable to have multiple children. Regarding our biological urge to reproduce, my point was that it is highly possible that people may choose not to procreate as a rational response to overpopulation; I'm not claiming other factors don't play a part. A good example of such a group is the Voluntary Human Extinction Movement (http://www.vhemt.org/). Granted, they are extreem and their end goal differs from someone who is simply trying to ease the effects of overpopulation, but they serve as an example of the conscious decision not to reproduce.

  3. I had a slightly different take on what Ruse and Wilson were proposing. I don't think they were proposing the your biological imperatives directly define morality, but rather one's biological makeup provides the foundation to have morality.

    If you reject dualism then your only left to assume your biology gave rise to your brain which gives rise to you. In essence, you are your brain. As Lungsi pointed our "humans are complex beings." But that complexity is biologically rooted.

    Part of that complexity is living as social beings, having reasoning capabilities, as well as having emotions. We have what Ruse and Wilson called a sense of "kin-ship" which influences our morality, and allows us to distinguish between our individual biological imperatives and what is good for society as a whole. Morality is related to the later not the former.

  4. I think it's hard to tell what Ruse and Wilson are proposing. Certainly, a charitable reading would be as Roger suggested: that we have evolved certain capacities for social interaction (including responsiveness to social norms). This is Kitcher's project 1 or 2 (depending on the specifics). But it SEEMS that they're often proposing that the evolution of our moral "sensibilities" EXHAUSTS what there is to know about morality (projects 3 or 4).

    Note that even projects 1 and 2 are not totally unproblematic: if evolutionary outcomes are very contingent (and we have every reason to believe that they are; see Gould's nice book Wonderful Life), then couldn't we have come out with a radically different set of norms? Some philosophers have argued on roughly these "Darwinian" grounds that we should abandon any hope for moral realism; see, for example, Sharon Street's "A Darwinian Dilemma for Realist Theories of Value".

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  6. oh, and I will take a look at Sharon Street's paper.

  7. Because of my background as a psychologist and neuroscientist I find it hard to completely disavowal myself of Ruse and Wilson. Clearly, as Kitcher pointed out they lack clear focus, and using naturalism as a foundation for discovering all moral knowledge is a foolhardy endeavor.

    Nevertheless, I think their is something to fact that their method of inquiry is empirically grounded. It gives it a sort of predictive validity other frameworks don't have. An empirical approach might allow us to build a model of a moral agent which tells us how people acquire morality (not strictly related to genetic determinism but extended to memes, environment, or pure chance), how they make moral decisions, what faculties are essential for this process to occur, why morality is so important. The moral agent would define essential components for forming and making moral judgments and the interactions between those components. In truth it becomes more of a descriptive approach were morality is an abstract psychological concept akin to emotion or color perception.

    In response to your point about the contingency of evolutionary outcomes. I think it's fair to say that while human's do share many norms they also exhibit variety between and within social groups. For instance, drug and alcohol use, capital punishment, and abortion come to mind. Ancient Egyptians practiced incest, and some African tribes practice cannibalism to this day.

    Perhaps rejecting realism isn't necessarily troublesome for this approach, and may in fact account for individual variability by incorporating other ethical theories. The argument could be made that individuals come to rely on a variety of different philosophical approaches, whether they are formally aware of them or not, for making moral decisions and actions. These philosophical approaches are like software that runs on the hardware of the moral agent (not the best analogy). In cases were philosophical approaches conflict, such as Kant's axe murderer, it is their weighting by the moral agent that makes the choose "obvious."

    How this approach might yield prescriptive utility is still something I'm tolling with, but because this approach describes how moral decisions are made and not merely what those decisions are; my intuition says that maybe it isn't limited to being purely descriptive, but because it is anti-realist rooted it probably is only possible to come up with optimum prescriptive norms.

    On the other hand I do think this approach could have great pragmatic utility. Let's assume flawless set of normative ethics could be established. Or perhaps more realistically one set proves much less error prone than the others. Then the question still remains "how does society acquire and learn to follow those norms?" Then a naturalistic framework has obvious potential.


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