From Entertainment Weekly:

EW: Are you religious?

Jodie Foster: No. I’m an atheist. But I absolutely love religions and the rituals.

Perhaps everyone enjoys rituals. (Even scientists.) It’s a curious enjoyment because rituals are arbitrary and without useful result. No other species has rituals. One sign of the pleasure we derive from rituals is obsessive-compulsive disorder (OCD). OCD takes many forms; one is excessive dependence on rituals, such as a need to do certain things, such as counting, tapping, or aligning, so often that it seriously interferes with being productive. The BBC program Am I Normal? did an excellent episode on OCD (no longer available). If you think of OCD (some forms) as addiction to rituals, the capacity of rituals to provide pleasure — or at least reduce anxiety — is clear.

Why do we enjoy rituals? I’ve already written about Christmas. Rituals and ceremonies, like Christmas and other gift-giving holidays, are a growth medium for fine craftsmanship. They encourage desire for fancy things – Christmas cards, special food, music, art, the special tools used in Japanese tea ceremonies. (Maybe the word fancy was invented to describe just these things, it fits so well.) They help support the highly-skilled artists and artisans who are advancing the state of their art. You can read my whole theory of human evolution here.

I became interested in the aquatic ape theory of evolution because it pointed me in a fruitful direction — testing omega-3 fatty acids (e.g., flaxseed oil), which turned out to have easy-to-detect benefits (better brain function, better gums). That is more than I can say for alternatives to that theory, such as the savanna theory. Marc Verhaegen, a Belgian doctor, has recently proposed a new version of the aquatic ape theory. Some of his main points:

• An extensive overview of the literature by Stephen Munro showed that virtually all known archaic Homo [= pre-Homo sapien] sites (including those in ‘savanna’) were associated with permanent water and edible shellfish.
• Only regular diving can explain archaic Homo’s pachy-osteo-sclerosis (POS), the extreme thickness and density of cranial and postcranial bones of most erectus-like fossils. . . . POS is only seen in slow littoral divers, e.g. dugong and manatee, walrus, Kolponomos, pakicetids, Odobenocetops, and Thalassocnus spp. Marine biologists agree POS has a hydrostatic function (ballast).
• The abundant brain-specific nutrients in aquatic foods (e.g. DHA, iodine) facilitated fast brain growth (sapiens’ poorer post-aquatic diet required a longer youth to grow the same brain size).
• Man is the opposite of a savanna inhabitant. Humans lack sun-reflecting fur, but have thermo-insulative subcutaneous fat layers, which are never seen in savanna mammals. We have a water- and sodium-wasting cooling system of abundant sweat glands, totally unfit for a dry environment. Our maximal urine concentration is much too low for a savanna-dwelling mammal. We need much more water than other primates, and have to drink more often than savanna inhabitants, yet we cannot drink large quantities at a time.
• Maps of human population densities show that, although we have become fully terrestrial today, we are still a waterside species, and almost half of human dietary calories still come from the water (e.g. rice, aquaculture, fish, shell- and crayfish).

I find the water-drinking point especially persuasive. We need to drink throughout the day, or at least feel bad if we cannot. Almost all workplaces, including cafes, have a source of water. This is inconsistent with savanna living and consistent with waterside living. The term aquatic ape is somewhat misleading. A better name would be aquatic-food ape.

In a recent post I proposed that we touch our mouths so much to transfer germs from our hands to our immune system. It’s an early warning system. The full sequence is: 1. Hands. 2. Skin around mouth. 3. Tongue (lick lips). 4. Tonsils (immune system). Forewarned is forearmed: exposure to a tiny amount of Germ X makes you much more likely to survive exposure to a large amount of Germ X.

Ants have a similar early-warning system, says a new study described here.

Cremer and her colleagues began by investigating how nestmates encountering an infected ant acted. They infected Lasius neglectus ants with Metarhizium anisopliae, a fungus that sticks to the insects’ outer cuticles and causes infection only after it has worked its way into the body, which takes a day or more. The researchers then placed infected or non-infected ants in a box with five nestmates, and watched what happened. . . . Ants without the spores were groomed at a constant rate over 5 days, while Cremer saw a spike in grooming of the fungus-infected ants in the first day or two of infection, suggesting that the pathogen was prompting a behavior change in the nestmates.

The grooming was protective:

But even though they’d been exposed, only 2 percent of nestmates died from fungal infections, even though half of the initially infected ants, which had been dipped in solvent with M. anisopliae spores, died within 5 days. When ants were exposed to a dose of fungus expected to cause a 2 percent death rate, Cremer’s group saw an increase in antifungal activity, suggesting that this low level of infection was indeed enough to stimulate a protective immune response.

Earlier studies had shown what is called “social immunization” (“a protection of naive individuals of a colony after social contact to exposed individuals”) among insects. This study was about how social immunization happens.

After I thought of this explanation of mouth touching, I became much less concerned about contact with sick people. I hadn’t known about social immunization.

My theory of human evolution posits that many features of human nature began because they increased specialization and trade. One is language. Language began with single words, I assume. The use of single words began and grew because they helped the two sides of trade find each other. The first language, in other words, was the first advertising. Advertising has two sides: (a) saying what you have too much of and (b) saying what you have too little of.

Single words are still used this way. Stores are often adorned with single words that say what they sell. When you go to an unfamiliar store, you may use single words to find what you want (“thermometers?”). The use of single words to convey desires is clear in a paper by Alexander Graham Bell, which I learned about from Electric Universe by David Bodanis. Bell (the inventor of the telephone) was a teacher of the deaf and wrote a paper about teaching deaf children language. His method involved labeling objects around the house with their names. One of his students was a five-year-old boy:

One morning he came downstairs in high spirits, very anxious to play with his doll. He frantically beat his shoulder with his hands, but I could not understand what he meant. I produced a toy-horse; but that was not what he wanted. A table; still he was disappointed. . . . At last, in desperation, he went to the card-rack, and, after a moment’s consideration, pulled out the word “doll” and presented it to me.

For a different view of why language evolved, see this paper by Hauser, Chomsky and Fitch.

I wrote this five years ago. Perhaps it is a holiday tradition to repost old posts about the deadweight loss of gifts.

In a kitchenware store a few years ago I came across the Rotary Nutcracker, a futuristic-looking device that cracks nuts in a new way. The girl at the cash register gave me a few walnuts to test it. It didn’t crack any of them. This was a curious product, I thought. Who would buy it? The salesperson told me that they’d stocked it for less than a year. I was the first person to test it. It had sold well during holiday season. Now I understood: people didn’t buy it for themselves, they bought it as a gift. As a gift, it mattered much less how well it worked — “it’s the thought that counts.” No wonder I was the first to test it.

Here, I saw, was my theory of human evolution in . . . well, a nutshell. Part of it. Humans are the only animals with occupational specialization — we specialize, and trade. It started with hobbies. Hobbies became part-time jobs. Part-time jobs became full-time jobs. To support full-time jobs — to generate enough demand for the products of this or that specialization — there has to be enough expertise, which builds up slowly. To build up expertise, our brains changed so as to cause creation of special events like Christmas, Japanese New Year, Spring Festival (in China), and a thousand other examples around the world. Such events increase the demand for high-end craftsmanship, thus helping the most skilled craftsmen — the ones most likely to advance the state of their art — make a living. Christmas increases the demand for Christmas cards (fine printing) and Christmas-tree ornaments, for example. Traditional gift-giving has the same effect: It increases demand for “the better things in life.” Most gifts, if you follow the usual norms, are (a) not something you would buy for yourself and (b) not something the recipient would buy. (As Alex Tabarrok has noticed.) They are harder to make — and thus reward skilled craftsmen more — than the stuff we buy for ourselves, just as Christmas ornaments are harder to make than common household objects and Christmas-card printing is more difficult than most printing. Weddings, with the gifts, finery, invitations, etc., are another example. The Rotary Nutcracker didn’t work in my tests but it almost worked. If enough people bought it as a gift, that would finance the research needed to improve it.

Marginal Revolution and James Surowiecki have recently written about the “deadweight loss of Christmas” — about how gifts tend to be worth less than their cost. I think they see this as bad thing but I see it as a good thing — at least, in our evolutionary past it was a good thing. Deadweight loss = research grant. Likewise, the denizens of The Devil Wears Prada appear slightly defensive about the social value of fashion. They seem to believe that fashion is less useful than “curing cancer” (by which they mean doing research to learn how to cure cancer). Actually, high fashion, with its hard-to-make skirts, belts, and accessories, is the same as curing cancer — they’re two ways of increasing the human skill set. Art is the old Science.

All cultures, as far as I know, have festivals and special celebratory days. At least they are extremely widespread — harvest festivals, for example. I believe they have a genetic basis. The underlying genes evolved because they increased sales of high-end “useless” stuff. This helped skilled artisans — a big source of technological innovation — make a living. Economists speak of the “deadweight loss” of Christmas because people buy stuff that would otherwise not be bought.

China retail giant Taobao (like Ebay, except better) has shown a shrewd understanding of the festival/shopping link. On Chinese campuses since the 1970s there has been a joke holiday called Singles Day (11-11). For people who are not in a relationship. In 2010 Taobao started having a sitewide sale on that day. This year total sales were $500 million. One retailer, one day. (For comparison, all US online retail sales for the 2010 holiday season were $33 billion.) No crowds, no difficulty parking, no long lines. Still stressful, yes, but in a good way: “This is so exciting – a war and a carnival at the same time,” said one shopper.