Punster: go on a hunting trip with Mick Jagger.
Maybe he's countersignalling, deliberately offering a superficially-negative signal in order to signal that he doesn't need to send the "expected" superficially-positive signal. See this article, also by Yvain.
There are big differences between "a study" and "a good study" and "a published study" and "a study that's been independently confirmed" and "a study that's been independently confirmed a dozen times over." These differences are important; when a scientist says something, it's not the same as the Pope saying it. It's only when dozens and hundreds of scientists start saying the same thing that we should start telling people to guzzle red wine out of a fire hose.
"Today we will be dragoons, until we are told otherwise"
"Where are our horses, then?"
"We must imagine them."
"Imaginary horses are much slower than the other kind."
Neal Stephenson, The Confusion
I stand corrected.
Here is the full article from which the quote was taken: http://www.johnlatour.com/barking_cats.htm
The preference alone is mostly harmless. When the preference is combined with the misapprehension that the preference can be fulfilled, it may harm the person asserting the preference if it leads them to make a bad choice between a meowing cat, a barking dog, or delaying the purchase of a pet.
If the preference order were (1. Barking Cat, 2. Barking Dog, 3. Meowing Cat, 4. No Pet), then the belief that a cat could be taught to bark could lead to the purchase/adoption of a meowing cat instead of the (preferred) barking dog.
Likewise, in the above preference order, or with 2 and 3 reversed, the belief in barking cats could also lead to the person delaying the selection of a pet due to the hope that a continued search would turn up a barking cat.
The problem is magnified, and more failure modes added, when we consider cases of group decision-making.
There are valid quibbles and exceptions on both counts. Some breeds of cats make vocalizations that can reasonably be described as "barking", and water will burn if there are sufficient concentrations of either an oxidizer much stronger than oxygen (such as chlorine triflouride) or a reducing agent much stronger than hydrogen (such as elemental sodium).
In the general case, though, water will not burn under normal circumstances, and most cats are physiologically incapable of barking.
The point of the quote is that objects and systems do have innate qualities that shape and limit their behaviour, and that this effect is present in social systems studied by economists as well as in physical systems studied by chemists and biologists. In the original context (which I elided because politics is the mind killer, and because any particular application of the principle is subject to empirical debate as to its validity), Friedman was following up on an article about how political economy considerations incline regulatory agencies towards socially suboptimal decisions, addressing responses that assumed that the political economy pressures could easily be designed away by revising the agencies' structures.
I replied as follows: "What would you think of someone who said, "I would like to have a cat, provided it barked"? [...] As a natural scientist, you recognize that you cannot assign characteristics at will to chemical and biological entities, cannot demand that cats bark or water burn. Why do you suppose that the situation is different in the "social sciences?"
-- Milton Friedman
I tried it for a few months in grad school. It works better than you'd expect, but not as well as you'd hope.
Days 2-3 were very rough, but after I acclimated, my subjective experience was similar to staying up a few hours past my normal bedtime (mild fatigue, but not unpleasant or debilitating if I was actively doing something).
Three things killed it for me:
It is very difficult to maintain a social life if you need to go home and nap every 3.5 hours on a strict schedule.
My class schedule was different on different days of the week, so I had to fudge my nap schedule around the classes. The fatigue was much worse on the days (Tuesdays and Thursdays, I think) that I couldn't keep my usual nap schedule.
Any stimulants at all will wreck the sleep cycle, and weird sleep cycle or no, I often find myself needing caffeine in order to acheive the mental energy I need to force myself to focus on something I need to get done.
As for formal experiments, the best source I know of is "Why We Nap: Evolution, Chronobiology, and Functions of Polyphasic and Ultrashort Sleep" by Claudio Stampi. It documents most of the existing studies as of when it was written (1992) as well as a formal study conducted by the author. It's out-of-print and fairly rare, but there's a PDF available here: http://sleepwarrior.com/Claudio_Stampi_-_Why_We_Nap.pdf