Good Turns

https://pixabay.com/en/britain-cab-car-city-classic-19228/

In order to get a license, London taxicab drivers must pass a punishing exam testing their memory of 25,000 streets and every significant business and landmark on them. “The Knowledge” has been called the hardest test of any kind in the world; applicants must put in thousands of hours of study to pass a series of progressively difficult oral exams that take, on average, four years to complete. The guidebook for prospective cabbies says:

To achieve the required standard to be licensed as an ‘All London’ taxi driver you will need a thorough knowledge, primarily, of the area within a six-mile radius of Charing Cross. You will need to know: all the streets; housing estates; parks and open spaces; government offices and departments; financial and commercial centres; diplomatic premises; town halls; registry offices; hospitals; places of worship; sports stadiums and leisure centres; airline offices; stations; hotels; clubs; theatres; cinemas; museums; art galleries; schools; colleges and universities; police stations and headquarters buildings; civil, criminal and coroner’s courts; prisons; and places of interest to tourists. In fact, anywhere a taxi passenger might ask to be taken.

Interestingly, licensed London cabbies show a significantly larger posterior hippocampus than non-taxi drivers. Psychologist Hugo J. Spiers writes, “Current evidence suggests that it is the acquisition of this spatial knowledge and its use on the job that causes the taxi driver’s posterior hippocampus to grow larger.” Apparently it’s not actually driving the streets, or learning the information alone, that causes the change — London bus drivers don’t show the same effect; nor do doctors, who must also acquire vast knowledge; nor do cabbies who fail the exam. Rather it seems to be the regular use of the knowledge that causes the change: Retired cabbies tend to have a smaller hippocampus than current drivers.

While driving virtual routes in fMRI studies, cabbies showed the most hippocampal activity at the moment a customer requested a destination. One cabbie said, “I’ve got an over-patched picture of Peter Street. It sounds daft, but I don’t view it from ground level, it was slightly up and I could see the whole area as though I was about 50 foot up. And I saw Peter Street, I saw the market and I knew I had to get down to Peter Street.” Non-cabbie volunteers also showed the most activity when they were planning a route. “Thus,” writes Spiers, “the engagement of the hippocampus appears to depend on the extent to which someone thinks about what the possible streets they might want to take during navigation.”

(Hugo J. Spiers, “Will Self and His Inner Seahorse,” in Sebastian Groes, ed., Memory in the Twenty-First Century, 2016.)

Summing Up

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In 1932, at the end of a 60-year career studying hydrodynamics, Sir Horace Lamb addressed the British Association for the Advancement of Science.

“I am an old man now,” he said, “and when I die and go to heaven there are two matters on which I hope for enlightenment. One is quantum electrodynamics, and the other is the turbulent motion of fluids. And about the former I am rather more optimistic.”

One for All?

https://www.flickr.com/photos/dave_hale/860846402
Image: Flickr

Suppose that there’s a power outage in your neighborhood. If someone calls the electric company, they’ll send someone to fix the problem. This puts you in a dilemma: If someone else makes the call, then you’ll benefit without having to do anything. But if no one calls, then you’ll all remain in the dark, which is the worst outcome:

volunteer's dilemma payoff matrix

This is the “volunteer’s dilemma,” a counterpart to the famous prisoner’s dilemma in game theory. Each participant has a greater incentive for “free riding” than acting, but if no one acts, then everyone loses.

A more disturbing example is the murder of Kitty Genovese, who was stabbed to death outside her New York City apartment in 1964. According to urban lore, many neighbors who were aware of the attack chose not to contact the police, trusting that someone else would make the call but hoping to avoid “getting involved.” Genovese died of her wounds.

In a 1988 paper, game theorist Anatol Rapaport noted, “In the U.S. Infantry Manual published during World War II, the soldier was told what to do if a live grenade fell into the trench where he and others were sitting: to wrap himself around the grenade so as to at least save the others. (If no one ‘volunteered,’ all would be killed, and there were only a few seconds to decide who would be the hero.)”

The Guinness Book of World Records lists the Yaghan word mamihlapinatapai as the “most succinct word.” It’s defined as “a look shared by two people, each wishing that the other would initiate something that they both desire but which neither wants to begin.”

(From William Poundstone, Prisoner’s Dilemma, 1992.)

Kindling Trouble

Now, for something a bit more serious: I am starting a new religion. Care to join? As with the Catholic religion, my religion has an index of forbidden books. There is only one book that the index forbids. Can you guess which? You probably have! It is the index itself!

— Raymond Smullyan, “Self-Reference in All Its Glory!”, conference “Self-Reference,” Copenhagen, Oct. 31-Nov. 2, 2002

Podcast Episode 121: Starving for Science

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During the siege of Leningrad in World War II, a heroic group of Russian botanists fought cold, hunger, and German attacks to keep alive a storehouse of crops that held the future of Soviet agriculture. In this week’s episode of the Futility Closet podcast we’ll tell the story of the Vavilov Institute, whose scientists literally starved to death protecting tons of treasured food.

We’ll also follow a wayward sailor and puzzle over how to improve the safety of tanks.

Intro:

Tippi Hedren, star of Alfred Hitchcock’s The Birds, shared her home with a 400-pound lion.

In 2009, a California consumer sued PepsiCo for implying that crunchberries are a fruit.

Sources for our feature on Nikolai Vavilov:

S.M. Alexanyan and V.I. Krivchenko, “Vavilov Institute Scientists Heroically Preserve World Plant Genetic Resources Collections During World War II Siege of Leningrad,” Diversity 7:4 (1991), 10-13.

James F. Crow, “N. I. Vavilov, Martyr to Genetic Truth,” Genetics 134:4 (May 1993).

Olga Elina, Susanne Heim, and Nils Roll-Hansen, “Plant Breeding on the Front: Imperialism, War, and Exploitation,” Osiris 20 (2005), 161-179.

Peter Pringle, The Murder of Nikolai Vavilov, 2008.

Boyce Rensberger, “Soviet Botanists Starved, Saving Seeds for Future,” Washington Post, May 12, 1992.

Michael Woods, “Soviet Union’s Fall Threatens ‘Gene Bank’ for Food Crops,” Pittsburgh Post-Gazette, April 26, 1993.

Joel I. Cohen and Igor G. Loskutov, “Exploring the Nature of Science Through Courage and Purpose,” SpringerPlus 5:1159 (2016).

Listener mail:

Peter Nichols, A Voyage for Madmen, 2001.

Nicholas Tomalin and Ron Hall, The Strange Last Voyage of Donald Crowhurst, 1970.

Ed Caesar, “Drama on the Waves: The Life and Death of Donald Crowhurst,” Independent, Oct. 27, 2006.

This week’s lateral thinking puzzle was contributed by listener Tommy Honton, who cites this source (warning: this link spoils the puzzle).

You can listen using the player above, download this episode directly, or subscribe on iTunes or Google Play Music or via the RSS feed at http://feedpress.me/futilitycloset.

Please consider becoming a patron of Futility Closet — on our Patreon page you can pledge any amount per episode, and all contributions are greatly appreciated. You can change or cancel your pledge at any time, and we’ve set up some rewards to help thank you for your support.

You can also make a one-time donation on the Support Us page of the Futility Closet website.

Many thanks to Doug Ross for the music in this episode.

If you have any questions or comments you can reach us at podcast@futilitycloset.com. Thanks for listening!

A Cognitive Illusion

https://www.flickr.com/photos/minhimalism/5708719581
Image: Flickr

Given these premises, what can you infer?

  1. If there is a king in the hand then there is an ace, or if there isn’t a king in the hand then there is an ace, but not both.
  2. There is a king in the hand.

Practically everyone draws the conclusion “There is an ace in the hand.” But this is wrong: We’ve been told that one of the conditional assertions in the first premise is false, so it may be false that “If there is a king in the hand, then there is an ace.”

But almost no one sees this. Princeton psychologist Philip Johnson-Laird writes, “[Fabien] Savary and I, together with various colleagues, have observed it experimentally; we have observed it anecdotally — only one person among the many distinguished cognitive scientists to whom we have given the problem got the right answer; and we have observed it in public lectures — several hundred individuals from Stockholm to Seattle have drawn it, and no one has ever offered any other conclusion.” Johnson-Laird himself thought he’d made a programming error when he first discovered the illusion in 1995.

Why it happens is unclear; in puzzling out problems like this, we seem to focus on what’s true and neglect what might be false. Computers are much better at this than we are, which ironically might lead a competent computer to fail the Turing test. In order to pass as human, writes researcher Selmer Bringsjord, “the machine must be smart enough to appear dull.”

(Philip N. Johnson-Laird, “An End to the Controversy? A Reply to Rips,” Minds and Machines 7 [1997], 425-432.)