An Introduction to Evolutionary Ethics (4 page)

The point of this little example is to emphasize the unlikely power of
form
or
law
in the creation of solutions. To be sure, writing a sonnet and designing species are dis-analogous in a variety of ways. Most notably, there is no analogy to the role of poet in the case of evolution; the metaphor of “tinkerer” is just that, a metaphor. There is selection going on in both instances, but the most that can be said in the case of evolution is that species are being selected for by the processes outlined above. Still, the metaphor is instructive: Mother Nature “tinkers” with the different designs that genetic mutations make available, just as we would tinker with words in composing a sonnet. Of course, like the vast majority of words you can think of, most organic alterations won't fit within the imposing confines already set up. Such alterations either don't fit locally (they're incompatible with the organism's internal structure) or globally (they decrease an organism's reproductive success relative to its neighbors). But every now and then, a slight modification of existing structure fits. Mother Nature's tinkering pays off. And, as in the case of writing the sonnet, the originality can be breathtaking: webbed feet, echolocation, poisonous venom, photosynthesis. Perhaps even thought.

So maybe we should take Richard Dawkins' advice: “Never say, and never take seriously anyone who says, ‘I cannot believe that so-and-so could have evolved by gradual selection.’ I have dubbed this kind of fallacy ‘the Argument from Personal Incredulity.’ Time and again, it has proven the prelude to an intellectual banana-skin experience” (1995: 70).

In the next section we build on these earlier scientific developments and explore the exciting (and controversial) new field of evolutionary psychology. As the name suggests, evolutionary psychology proposes to study the human mind in the same way that evolutionary biologists study organic form: by applying the principles of Darwinian selection. In this case, the objects of study are patterns of human behavior, patterns of human thought and desire. The study is directly relevant to our main focus, for it is often within the field of evolutionary psychology that some theorists locate the evidence for an evolved moral sense.
⁵

1.4 Evolutionary Psychology and Human Nature You may have no problem accepting a Darwinian explanation for the structure of the human eye. Ditto for the human lungs, liver, colon, and circulation system. But what about jealousy? What about friendship? What about men's proneness to violence, or women's interest in looking young? What about language?
These
things, you say, are another matter. Perhaps not, say evolutionary psychologists.

Today, Darwin's ideas about evolution occupy an interesting place. On the one hand, when it comes to explaining the
bodily
features of human beings (the human heart or the human hip joint), most people have no problem appealing to evolution by natural selection. On the other hand, when it comes to explaining the
psychological
features of human beings, people resist appealing to evolution by natural selection – if it occurs to them at all. Apparently, there is an explanatory divide between the human body and the human mind. That divide is perpetuated (I suspect) by the weatherbeaten distinction between nature and nurture.

The prevailing assumption is that the human body is as it is
by nature
(for example, you didn't learn to grow legs instead of fins), whereas the human mind is as it is
by nurture.
Your attitudes about what makes a desirable mate, for example, were primarily shaped by your environment. That divide between body and mind, however, is eroding. In this section, we explore what some are calling the new science of the mind, evolutionary psychology, which actively seeks to integrate psychology and evolutionary biology.

Contrary to the prevailing assumption, evolutionary psychology maintains that there is a common explanatory framework underlying both human physiology and human psychology: evolution by natural selection. A complete understanding of the human mind, according to evolutionary psychologists, requires understanding the evolutionary pressures that shaped it so many millions of years ago. We do not come into the world as blank slates, as many commonly assume. Instead, they argue, our heads are full of psychological
adaptations
.

Of course, when asked to think of evolutionary adaptations most of us think of
anatomical
features like a duck's webbed feet or a lizard's camouflaged skin. According to the standard account, webbed feet initially arose as a result of a genetic mutation; because webbed feet enabled their possessor to out-reproduce its neighbors (all things considered), over time webbed feet spread to the entire population. Evolutionary psychologists are proposing a similar account for
mental
features. At some point in the distant past, a certain mental system arose in an individual as a result of a genetic mutation; this system altered her psychology – the way she thought or felt or reasoned or desired. And because this system enabled her to out-reproduce her neighbors (all things considered), over time that mental system spread to the entire population. Speaking grandly, we might say that just as webbed feet are part of a duck's nature, so, too, certain ways of thinking or reasoning or desiring are part of human nature.

Returning for a moment to our main theme (i.e. the human moral sense), we can put our question this way: Is having a moral sense part of human nature, where that nature is best explained by evolution by natural selection? As we'll see below, in order to answer that question we will need to look carefully at the kind of adaptive problem (if any) that our moral sense was designed to solve. Webbed feet, for instance, helped solve the problem of efficient movement through water. If our moral sense is indeed an adaptation, then there should be good evidence that possession of such a sense helped to solve (or to solve more successfully than one's neighbors) a particular adaptive problem. But we're getting ahead of ourselves. Let's look more closely at the details of evolutionary psychology.

1.5 An Evolved Mental Tool-Box Evolutionary psychologists hypothesize that the human mind is equipped with many (some say very many) different evolved psychological mechanisms. Instead of viewing the mind as containing a single all-purpose “problem-solver,” evolutionary psychologists view the mind in roughly the way we view the body. We know the body does not contain a
single
anatomical mechanism to deal with the body's journey through the world. Rather, it contains
different
mechanisms to confront
different
problems: a liver to filter out toxins, lungs to take in oxygen, antibodies to fight off bacteria and viruses, and so on. It's true that each mechanism is profoundly limited in what it can do (your digestive system is a pretty bad listener), but this cost is more than offset by the benefits. With only one task to complete, each system should be able to do it efficiently, economically, and quite reliably.
⁶
And even if other systems break down (you lose your eyesight, for example), most other systems should remain operational.

Evolutionary psychologists contend that this is the way we should understand the human mind.
⁷
Like the body, the mind requires different mechanisms to deal with different tasks. After all, the alternative to this picture – a single, all-purpose psychological mechanism – is, say evolutionary psychologists, hard to accept: The idea that a single generic substance can see in depth, control the hands, attract a mate, bring up children, elude predators, outsmart prey, and so on, without
some
degree of specialization, is not credible. Saying that the brain solves these problems because of its “plasticity” is not much better than saying it solves them by magic. (Pinker 1997: 75) What we're left with, then, is what some psychologists call a “modular” account of the mind: many distinct modules designed to solve many distinct problems. That is, many distinct “tools” to take on many distinct problems. It's an
evolutionary
account because natural selection is responsible for the design. But what are these modules?

According to David Buss, a leading evolutionary psychologist, an evolved psychological module or mechanism is “a set of procedures within the organism that is designed to take in a particular slice of information and transform that information via decision rules into output that historically has helped with the solution to an adaptive problem” (2007: 52). What does this mean? Well, first, by “a set of procedures,” Buss is acknowledging that there may be many subsystems involved in delivering information from the environment to the mechanism. Visual systems, auditory systems, chains of logical inference, all of these may deliver information to the mechanism. Nevertheless, the mechanism is designed to take in
only
“a particular slice of information.” The mechanism for choosing mates, for example, will not process information regarding the color of the grass or the taste of the berries or the speed of passing clouds. Instead, that mechanism (it is alleged) is designed to take in and process only that information that is relevant to choosing a mate, and which information is relevant will depend on the operative “decision rules.” Such rules (we can imagine) amount to “If … then” clauses:
if
the mechanism registers so-and-so,
then
do thus-and-so and/or think so-and-so.
⁸
Because these rules do not process information about innumerable other things (just as your house-key does not open innumerable locks), that mechanism is described as
dedicated
or
domain-specific
.

Finally, the presence of
this
mechanism – as opposed to some other mechanism – is explained by the fact that, given the preexisting materials of the hominid brain,
this
mechanism helped to solve an adaptive problem that confronted our hominid ancestors. This last part is extremely important. The psychological mechanisms that evolutionary psychologists claim fill the mind did not evolve to in response to problems we confront today. They
may
help in solving similar problems today, but that's not why we possess them. We possess them because they solved recurrent problems confronting our distant ancestors. And since they haven't been “selected out” of the population, current populations still posses them. As evolutionary psychologists like to say, our modern skulls house stone-age minds.

1.6 Some (More) Common Misunderstandings As you might imagine, when the topic turns to human nature (and the alleged evolutionary roots of that nature), the landscape is suddenly awash in landmines. From the rather straightforward biological story above, it is easy to find oneself concluding all sorts of dubious things. I want to spend a few moments warning against several dangerous missteps: (1) conflating adaptation and adaptiveness; (2) conflating explanation and justification; (3) misunderstanding the scope of an evolutionary explanation; and (4) succumbing to the temptation of genetic determinism.

Conflating adaptation and adaptiveness One of the most seductive confusions in this area concerns the distinction (and there
is
one) between adaptations and adaptiveness. Simply put, what is adaptive is not necessarily an adaptation, and adaptations are not necessarily adaptive. Some examples will help. Going to your doctor for an annual physical is adaptive insofar as it increases your chances of survival and reproduction; however, no one is going to conclude that the mind possesses a “going to the doctor” mechanism, dedicated to identifying doctors and motivating the organism to seek out their counsel. Going to the doctor is, if you will, a
learned
behavior – at least for those who learned it. The point is that we should be careful not to conclude that a piece of behavior is (or, more carefully put, is produced by) a psychological adaptation
just because it happens to be biologically adaptive
.

What is perhaps less obvious is the claim that adaptations are not necessarily adaptive. When an evolutionary psychologist claims that a piece of behavior is produced by a psychological adaptation (let's call it
A
), she is
not
claiming that
A
produces adaptive behavior. She is claiming, instead, that
A
,
on average
, tended to produce behavior that was more adaptive than competing designs
in the environment in which A evolved.
But the environment in which
A
evolved may not resemble our current environment; hence, there is no guarantee that
A
will be adaptive in this current environment. Think of it this way. By most estimates, 99 percent of our species' history consisted of hunting and gathering under the harsh conditions of the African savannah. So the psychological mechanisms that evolved evolved in response to
those
conditions. But now imagine transplanting that “stone-age mind” into the skull of a citizen of the modern world, with its maze of office cubicles and public transportation, its online dating and jury duty, its Google and Facebook, its GPSs and ATMs. Is it any wonder that some of our stone-age solutions (to adaptive problems) are not up to the task of the problems of the modern world?

Return to an example discussed in the Introduction: our preference for fatty foods. It should be immediately obvious that early humans regularly confronted the problem of getting enough to eat. One solution to this problem would have been a greater discrimination in respect of what one ate: preferring fatty foods increased one's chances of increasing caloric intake thereby increasing one's store of energy and so on. But that same solution – a strong preference for fatty foods – that was so adaptive during the period of hominid development is decidedly
non
-adaptive in environments rich in cheeseburgers and chocolate doughnuts. Again, the point to bear in mind is that when it is claimed that such-and-such is a psychological adaptation, the claim should be understood, first and foremost, as a claim about our
evolutionary past
, about a particular psychological solution to an adaptive problem that repeatedly confronted our distant ancestors. Whether or not that solution is well suited to our current environments is a separate matter.