But I ask in return: If we can’t see clearly the result of a single monotone optimization criterion—if we can’t even train ourselves to hear a single pure note—then how will we listen to an orchestra? How will we see that “Always be selfish” or “Always obey the government” are poor guiding principles for human beings to adopt—if we think that even optimizing genes for inclusive fitness will yield organisms that sacrifice reproductive opportunities in the name of social resource conservation?
To train ourselves to see clearly, we need simple practice cases.
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138
Adaptation-Executers, Not Fitness-Maximizers
Individual organisms are best thought of as adaptation-executers rather than as fitness-maximizers.
—John Tooby and Leda Cosmides,
“The Psychological Foundations of Culture”1
Fifty thousand years ago, the taste buds of Homo sapiens directed their bearers to the scarcest, most critical food resources—sugar and fat. Calories, in a word. Today, the context of a taste bud’s function has changed, but the taste buds themselves have not. Calories, far from being scarce (in First World countries), are actively harmful. Micronutrients that were reliably abundant in leaves and nuts are absent from bread, but our taste buds don’t complain. A scoop of ice cream is a superstimulus, containing more sugar, fat, and salt than anything in the ancestral environment.
No human being with the deliberate goal of maximizing their alleles’ inclusive genetic fitness would ever eat a cookie unless they were starving. But individual organisms are best thought of as adaptation-executers, not fitness-maximizers.
A Phillips-head screwdriver, though its designer intended it to turn screws, won’t reconform itself to a flat-head screw to fulfill its function. We created these tools, but they exist independently of us, and they continue independently of us.
The atoms of a screwdriver don’t have tiny little XML tags inside describing their “objective” purpose. The designer had something in mind, yes, but that’s not the same as what happens in the real world. If you forgot that the designer is a separate entity from the designed thing, you might think, “The purpose of the screwdriver is to drive screws”—as though this were an explicit property of the screwdriver itself, rather than a property of the designer’s state of mind. You might be surprised that the screwdriver didn’t reconfigure itself to the flat-head screw, since, after all, the screwdriver’s purpose is to turn screws.
The cause of the screwdriver’s existence is the designer’s mind, which imagined an imaginary screw, and imagined an imaginary handle turning. The actual operation of the screwdriver, its actual fit to an actual screw head, cannot be the objective cause of the screwdriver’s existence: The future cannot cause the past. But the designer’s brain, as an actually existent thing within the past, can indeed be the cause of the screwdriver.
The consequence of the screwdriver’s existence may not correspond to the imaginary consequences in the designer’s mind. The screwdriver blade could slip and cut the user’s hand.
And the meaning of the screwdriver—why, that’s something that exists in the mind of a user, not in tiny little labels on screwdriver atoms. The designer may intend it to turn screws. A murderer may buy it to use as a weapon. And then accidentally drop it, to be picked up by a child, who uses it as a chisel.
So the screwdriver’s cause, and its shape, and its consequence, and its various meanings, are all different things; and only one of these things is found within the screwdriver itself.
Where do taste buds come from? Not from an intelligent designer visualizing their consequences, but from a frozen history of ancestry: Adam liked sugar and ate an apple and reproduced, Barbara liked sugar and ate an apple and reproduced, Charlie liked sugar and ate an apple and reproduced, and 2763 generations later, the allele became fixed in the population. For convenience of thought, we sometimes compress this giant history and say: “Evolution did it.” But it’s not a quick, local event like a human designer visualizing a screwdriver. This is the objective cause of a taste bud.
What is the objective shape of a taste bud? Technically, it’s a molecular sensor connected to reinforcement circuitry. This adds another level of indirection, because the taste bud isn’t directly acquiring food. It’s influencing the organism’s mind, making the organism want to eat foods that are similar to the food just eaten.
What is the objective consequence of a taste bud? In a modern First World human, it plays out in multiple chains of causality: from the desire to eat more chocolate, to the plan to eat more chocolate, to eating chocolate, to getting fat, to getting fewer dates, to reproducing less successfully. This consequence is directly opposite the key regularity in the long chain of ancestral successes that caused the taste bud’s shape. But, since overeating has only recently become a problem, no significant evolution (compressed regularity of ancestry) has further influenced the taste bud’s shape.
What is the meaning of eating chocolate? That’s between you and your moral philosophy. Personally, I think chocolate tastes good, but I wish it were less harmful; acceptable solutions would include redesigning the chocolate or redesigning my biochemistry.
Smushing several of the concepts together, you could sort-of-say, “Modern humans do today what would have propagated our genes in a hunter-gatherer society, whether or not it helps our genes in a modern society.” But this still isn’t quite right, because we’re not actually asking ourselves which behaviors would maximize our ancestors’ inclusive fitness. And many of our activities today have no ancestral analogue. In the hunter-gatherer society there wasn’t any such thing as chocolate.
So it’s better to view our taste buds as an adaptation fitted to ancestral conditions that included near-starvation and apples and roast rabbit, which modern humans execute in a new context that includes cheap chocolate and constant bombardment by advertisements.
Therefore it is said: Individual organisms are best thought of as adaptation-executers, not fitness-maximizers.
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1. John Tooby and Leda Cosmides, “The Psychological Foundations of Culture,” in The Adapted Mind: Evolutionary Psychology and the Generation of Culture, ed. Jerome H. Barkow, Leda Cosmides, and John Tooby (New York: Oxford University Press, 1992), 19–136.
139
Evolutionary Psychology
Like “IRC chat” or “TCP/IP protocol,” the phrase “reproductive organ” is redundant. All organs are reproductive organs. Where do a bird’s wings come from? An Evolution-of-Birds Fairy who thinks that flying is really neat? The bird’s wings are there because they contributed to the bird’s ancestors’ reproduction. Likewise the bird’s heart, lungs, and genitals. At most we might find it worthwhile to distinguish between directly reproductive organs and indirectly reproductive organs.
This observation holds true also of the brain, the most complex organ system known to biology. Some brain organs are directly reproductive, like lust; others are indirectly reproductive, like anger.
Where does the human emotion of anger come from? An Evolution-of-Humans Fairy who thought that anger was a worthwhile feature? The neural circuitry of anger is a reproductive organ as surely as your liver. Anger exists in Homo sapiens because angry ancestors had more kids. There’s no other way it could have gotten there.
This historical fact about the origin of anger confuses all too many people. They say, “Wait, are you saying that when I’m angry, I’m subconsciously trying to have children? That’s not what I’m thinking after someone punches me in the nose.”
No. No. No. NO!
Individual organisms are best thought of as adaptation-executers, not fitness-maximizers. The cause of an adaptation, the shape of an adaptation, and the consequence of an adaptation are all separate things. If you built a toaster, you wouldn’t expect the toaster to reshape itself when you tried to cram in a whole loaf of bread; yes, you intended it to make toast, but that intention is a fact about you, not a fact about the toaster. Th
e toaster has no sense of its own purpose.
But a toaster is not an intention-bearing object. It is not a mind at all, so we are not tempted to attribute goals to it. If we see the toaster as purposed, we don’t think the toaster knows it, because we don’t think the toaster knows anything.
It’s like the old test of being asked to say the color of the letters in “blue.” It takes longer for subjects to name this color, because of the need to untangle the meaning of the letters and the color of the letters. You wouldn’t have similar trouble naming the color of the letters in “wind.”
But a human brain, in addition to being an artifact historically produced by evolution, is also a mind capable of bearing its own intentions, purposes, desires, goals, and plans. Both a bee and a human are designs, but only a human is a designer. The bee is “wind;” the human is “blue.”
Cognitive causes are ontologically distinct from evolutionary causes. They are made out of a different kind of stuff. Cognitive causes are made of neurons. Evolutionary causes are made of ancestors.
The most obvious kind of cognitive cause is deliberate, like an intention to go to the supermarket, or a plan for toasting toast. But an emotion also exists physically in the brain, as a train of neural impulses or a cloud of spreading hormones. Likewise an instinct, or a flash of visualization, or a fleetingly suppressed thought; if you could scan the brain in three dimensions and you understood the code, you would be able to see them.
Even subconscious cognitions exist physically in the brain. “Power tends to corrupt,” observed Lord Acton. Stalin may or may not have believed himself an altruist, working toward the greatest good for the greatest number. But it seems likely that, somewhere in Stalin’s brain, there were neural circuits that reinforced pleasurably the exercise of power, and neural circuits that detected anticipations of increases and decreases in power. If there were nothing in Stalin’s brain that correlated to power—no little light that went on for political command, and off for political weakness—then how could Stalin’s brain have known to be corrupted by power?
Evolutionary selection pressures are ontologically distinct from the biological artifacts they create. The evolutionary cause of a bird’s wings is millions of ancestor-birds who reproduced more often than other ancestor-birds, with statistical regularity owing to their possession of incrementally improved wings compared to their competitors. We compress this gargantuan historical-statistical macrofact by saying “evolution did it.”
Natural selection is ontologically distinct from creatures; evolution is not a little furry thing lurking in an undiscovered forest. Evolution is a causal, statistical regularity in the reproductive history of ancestors.
And this logic applies also to the brain. Evolution has made wings that flap, but do not understand flappiness. It has made legs that walk, but do not understand walkyness. Evolution has carved bones of calcium ions, but the bones themselves have no explicit concept of strength, let alone inclusive genetic fitness. And evolution designed brains themselves capable of designing; yet these brains had no more concept of evolution than a bird has of aerodynamics. Until the twentieth century, not a single human brain explicitly represented the complex abstract concept of inclusive genetic fitness.
When we’re told that “The evolutionary purpose of anger is to increase inclusive genetic fitness,” there’s a tendency to slide to “The purpose of anger is reproduction” to “The cognitive purpose of anger is reproduction.” No! The statistical regularity of ancestral history isn’t in the brain, even subconsciously, any more than the designer’s intentions of toast are in a toaster!
Thinking that your built-in anger-circuitry embodies an explicit desire to reproduce is like thinking your hand is an embodied mental desire to pick things up.
Your hand is not wholly cut off from your mental desires. In particular circumstances, you can control the flexing of your fingers by an act of will. If you bend down and pick up a penny, then this may represent an act of will; but it is not an act of will that made your hand grow in the first place.
One must distinguish a one-time event of particular anger (anger-1, anger-2, anger-3) from the underlying neural circuitry for anger. An anger-event is a cognitive cause, and an anger-event may have cognitive causes, but you didn’t will the anger-circuitry to be wired into the brain.
So you have to distinguish the event of anger, from the circuitry of anger, from the gene complex that laid down the neural template, from the ancestral macrofact that explains the gene complex’s presence.
If there were ever a discipline that genuinely demanded X-Treme Nitpicking, it is evolutionary psychology.
Consider, O my readers, this sordid and joyful tale: A man and a woman meet in a bar. The man is attracted to her clear complexion and firm breasts, which would have been fertility cues in the ancestral environment, but which in this case result from makeup and a bra. This does not bother the man; he just likes the way she looks. His clear-complexion-detecting neural circuitry does not know that its purpose is to detect fertility, any more than the atoms in his hand contain tiny little XML tags reading “
To reason correctly about evolutionary psychology you must simultaneously consider many complicated abstract facts that are strongly related yet importantly distinct, without a single mixup or conflation.
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140
An Especially Elegant Evolutionary Psychology Experiment
In a 1989 Canadian study, adults were asked to imagine the death of children of various ages and estimate which deaths would create the greatest sense of loss in a parent. The results, plotted on a graph, show grief growing until just before adolescence and then beginning to drop. When this curve was compared with a curve showing changes in reproductive potential over the life cycle (a pattern calculated from Canadian demographic data), the correlation was fairly strong. But much stronger—nearly perfect, in fact—was the correlation between the grief curves of these modern Canadians and the reproductive-potential curve of a hunter-gatherer people, the !Kung of Africa. In other words, the pattern of changing grief was almost exactly what a Darwinian would predict, given demographic realities in the ancestral environment.
—Robert Wright, The Moral Animal,
summarizing Crawford et al.1
The first correlation was 0.64, the second an extremely high 0.92 (N = 221).
The most obvious inelegance of this study, as described, is that it was conducted by asking human adults to imagine parental grief, rather than asking real parents with children of particular ages. (Presumably that would have cost more / allowed fewer subjects.) However, my understanding is that the results here squared well with the data from closer studies of parental grief that were looking for other correlations (i.e., a raw correlation between parental grief and child age).
That said, c
onsider some of this experiment’s elegant aspects:
A correlation of 0.92(!) This may sound suspiciously high—could evolution really do such exact fine-tuning?—until you realize that this selection pressure was not only great enough to fine-tune parental grief, but, in fact, carve it out of existence from scratch in the first place.
People who say that evolutionary psychology hasn’t made any advance predictions are (ironically) mere victims of “no one knows what science doesn’t know” syndrome. You wouldn’t even think of this as an experiment to be performed if not for evolutionary psychology.
The experiment illustrates, as beautifully and as cleanly as any I have ever seen, the distinction between a conscious or subconscious ulterior motive and an executing adaptation with no realtime sensitivity to the original selection pressure that created it.
The parental grief is not even subconsciously about reproductive value—otherwise it would update for Canadian reproductive value instead of !Kung reproductive value. Grief is an adaptation that now simply exists, real in the mind and continuing under its own inertia.
Parents do not care about children for the sake of their reproductive contribution. Parents care about children for their own sake; and the non-cognitive, evolutionary-historical reason why such minds exist in the universe in the first place is that children carry their parents’ genes.
Indeed, evolution is the reason why there are any minds in the universe at all. So you can see why I’d want to draw a sharp line through my cynicism about ulterior motives at the evolutionary-cognitive boundary; otherwise, I might as well stand up in a supermarket checkout line and say, “Hey! You’re only correctly processing visual information while bagging my groceries in order to maximize your inclusive genetic fitness!”
Rationality- From AI to Zombies Page 53