Though I know more about the former than the latter, I begin to suspect that different styles of cynicism prevail in evolutionary psychology than in microeconomics.

Evolutionary psychologists are absolutely and uniformly cynical about the real reason why humans are universally wired with a chunk of complex purposeful functional circuitry X (e.g. an emotion) - we have X because it increased inclusive genetic fitness in the ancestral environment, full stop.

Evolutionary psychologists are mildly cynical about the environmental circumstances that activate and maintain an emotion.  For example, if you fall in love with the body, mind, and soul of some beautiful mate, an evolutionary psychologist would like to check up on you in ten years to see whether the degree to which you think your mate's mind is still beautiful, correlates with independent judges' ratings of how physically attractive that mate still is.

But it wouldn't be conventionally ev-psych cynicism to suppose that you don't really love your mate, and that you were actually just attracted to their body all along, but that instead you told yourself a self-deceiving story about virtuously loving them for their mind, in order to falsely signal commitment.

Robin, on the other hand, often seems to think that this general type of cynicism is the default explanation and that anything else bears a burden of proof - why suppose an explanation that invokes a genuine virtue, when a selfish desire will do?

Of course my experience with having deep discussions with economists mostly consists of talking to Robin, but I suspect that this is at least partially reflective of a difference between the ev-psych and economic notions of parsimony.

Ev-psychers are trying to be parsimonious with how complex of an adaptation they postulate, and how cleverly complicated they are supposing natural selection to have been.

Economists... well, it's not my field, but maybe they're trying be parsimonious by having just a few simple motives that play out in complex ways via consequentialist calculations?

Followup to:  Anthropomorphic Optimism

Aristotle distinguished between four senses of the Greek word aition, which in English is translated as "cause", though Wikipedia suggests that a better translation is "maker".  Aristotle's theory of the Four Causes, then, might be better translated as the Four Makers.  These were his four senses of aitia:  The material aition, the formal aition, the efficient aition, and the final aition.

The material aition of a bronze statue is the substance it is made from, bronze.  The formal aition is the substance's form, its statue-shaped-ness.  The efficient aition best translates as the English word "cause"; we would think of the artisan carving the statue, though Aristotle referred to the art of bronze-casting the statue, and regarded the individual artisan as a mere instantiation.

The final aition was the goal, or telos, or purpose of the statue, that for the sake of which the statue exists.

Though Aristotle considered knowledge of all four aitia as necessary, he regarded knowledge of the telos as the knowledge of highest order.  In this, Aristotle followed in the path of Plato, who had earlier written:

Imagine not being able to distinguish the real cause from that without which the cause would not be able to act as a cause.  It is what the majority appear to do, like people groping in the dark; they call it a cause, thus giving it a name that does not belong to it.  That is why one man surrounds the earth with a vortex to make the heavens keep it in place, another makes the air support it like a wide lid.  As for their capacity of being in the best place they could possibly be put, this they do not look for, nor do they believe it to have any divine force...

Followup to:  Humans in Funny Suits

This fallacy gets its name from an ancient sci-fi TV show, which I never saw myself, but was reported to me by a reputable source (some guy at an SF convention).  Anyone knows the exact reference, do leave a comment.

So the good guys are battling the evil aliens.  Occasionally, the good guys have to fly through an asteroid belt.  As we all know, asteroid belts are as crowded as a New York parking lot, so their ship has to carefully dodge the asteroids.  The evil aliens, though, can fly right through the asteroid belt because they have amazing technology that dematerializes their ships, and lets them pass through the asteroids.

Eventually, the good guys capture an evil alien ship, and go exploring inside it.  The captain of the good guys finds the alien bridge, and on the bridge is a lever.  "Ah," says the captain, "this must be the lever that makes the ship dematerialize!"  So he pries up the control lever and carries it back to his ship, after which his ship can also dematerialize.

Similarly, to this day, it is still quite popular to try to program an AI with "semantic networks" that look something like this:

(apple is-a fruit)
(fruit is-a food)
(fruit is-a plant)

Followup to:  Evolutions Are Stupid (But Work Anyway), Evolutionary Psychology

Biological organisms in general, and human brains particularly, contain complex adaptations; adaptations which involve many genes working in concert. Complex adaptations must evolve incrementally, gene by gene.  If gene B depends on gene A to produce its effect, then gene A has to become nearly universal in the gene pool before there's a substantial selection pressure in favor of gene B.

A fur coat isn't an evolutionary advantage unless the environment reliably throws cold weather at you.  And other genes are also part of the environment; they are the genetic environment.  If gene B depends on gene A, then gene B isn't a significant advantage unless gene A is reliably part of the genetic environment.

Let's say that you have a complex adaptation with six interdependent parts, and that each of the six genes is independently at ten percent frequency in the population.  The chance of assembling a whole working adaptation is literally a million to one; and the average fitness of the genes is tiny, and they will not increase in frequency.

In a sexually reproducing species, complex adaptations are necessarily universal.

Followup to:  Rational vs. Scientific Ev-Psych, The Tragedy of Group Selectionism, Evolving to Extinction

Perhaps the real reason that evolutionary "just-so stories" got a bad name is that so many attempted stories are prima facie absurdities to serious students of the field.

As an example, consider a hypothesis I've heard a few times (though I didn't manage to dig up an example).  The one says:  Where does religion come from?  It appears to be a human universal, and to have its own emotion backing it - the emotion of religious faith.  Religion often involves costly sacrifices, even in hunter-gatherer tribes - why does it persist?  What selection pressure could there possibly be for religion?

So, the one concludes, religion must have evolved because it bound tribes closer together, and enabled them to defeat other tribes that didn't have religion.

This, of course, is a group selection argument - an individual sacrifice for a group benefit - and see the referenced posts if you're not familiar with the math, simulations, and observations which show that group selection arguments are extremely difficult to make work.  For example, a 3% individual fitness sacrifice which doubles the fitness of the tribe will fail to rise to universality, even under unrealistically liberal assumptions, if the tribe size is as large as fifty.  Tribes would need to have no more than 5 members if the individual fitness cost were 10%.  You can see at a glance from the sex ratio in human births that, in humans, individual selection pressures overwhelmingly dominate group selection pressures.  This is an example of what I mean by prima facie absurdity.

Prerequisite:  Evolutionary Psychology

Years ago, before I left my parents' nest, I was standing in front of a refrigerator, looking inside.  My mother approached and said, "What are you doing?"  I said, "Looking for the ketchup.  I don't see it."

My mother reached behind a couple of bottles and took out the ketchup.

She said, "If you don't see the ketchup, why don't you move things around and look behind them, instead of just standing and staring into the refrigerator?  Do you think the ketchup is magically going to appear if you stare into the refrigerator long enough?"

And lo, the light went on over my head, and I said:  "Men are hunters, so if we can't find our prey, we instinctively freeze motionless and wait for it to wander into our field of vision.  Women are gatherers, so they move things around and look behind them."

Now this sort of thing is not scientifically respectable; it is called a "just-so story", after Kipling's "Just-So Stories" like "How the Camel Got His Hump".  The implication being that you can make up anything you like for an evolutionary story, but the difficult thing is finding a way to prove it.

Well, fine, but I bet it's still true.

Followup to:  An Alien God, Adaptation-Executers not Fitness-Maximizers, Evolutionary Psychology

Before the 20th century, not a single human being had an explicit concept of "inclusive genetic fitness", the sole and absolute obsession of the blind idiot god.  We have no instinctive revulsion of condoms or oral sex.  Our brains, those supreme reproductive organs, don't perform a check for reproductive efficacy before granting us sexual pleasure.

Why not?  Why aren't we consciously obsessed with inclusive genetic fitness?  Why did the Evolution-of-Humans Fairy create brains that would invent condoms?  "It would have been so easy," thinks the human, who can design new complex systems in an afternoon.

Followup to:  Evolutionary Psychology

It takes hundreds of generations for a simple beneficial mutation to promote itself to universality in a gene pool.  Thousands of generations, or even millions, to create complex interdependent machinery.

That's some slow learning there.  Let's say you're building a squirrel, and you want the squirrel to know locations for finding nuts.  Individual nut trees don't last for the thousands of years required for natural selection.  You're going to have to learn using proteins.  You're going to have to build a brain.

Followup to:  An Alien God, Adaptation-Executers not Fitness-Maximizers

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 rather than as fitness-maximizers."
        —John Tooby and Leda Cosmides, The Psychological Foundations of Culture.

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.