When Do Fish Sleep? (30 page)

Needless to say, a coachman wouldn’t have felt quite as secure sitting to the right of the driver. Every time a right-handed driver got ready to crack the whip, the coachman would have had to duck and cover.

The British built their cars with the steering wheel on the right because their wagons and carriages at the time still stuck to the left side of the road. Their foot controls, however, have always been the same as American cars.

Well more than a hundred readers sent responses to this Frustable, most of them containing fragments of this explanation. Hopper’s article is the best summary of the conventional wisdom on this subject that we have encountered. But there are dissenters. Patricia A. Guy, a reference librarian at the Bay Area Library and Information System in Oakland, California, was kind enough to send us several articles on this subject, including a fascinating one called “The Rule of the Road” from a 1908 periodical called
Popular Science Monthly
. Its author, George M. Gould, M.D., argues that Americans had adopted right-hand side travel before the development of Conestoga wagons, as had the French, whose wagons were driven by postilion riders (mounted on the left-rear horse). Dr. Gould couldn’t come up with a convincing theory for the switch and argued that this Imponderable was likely to be a Frustable for all time.

We include this dissent to indicate that we tend to lunge at any answer that neatly solves a difficult question. We can give you a logical reason why Americans and the French switched the traditional custom of driving on the left; but we wouldn’t risk our already precarious reputations on it.

Submitted by Claudia Wiehl of North Charleroi, Pennsylvania. Thanks also to John Haynes of Independence, Kentucky; Kathi Sawyer-Young of Encino, California; Larry S. Londre of Studio City, California; David Andrews of Dallas, Texas; Hugo Kahn of New York, New York; Barbara Dilworth of Bloomsburg, Pennsylvania; Pat Mooney of Inglewood, California; Stephen Murphy of Smithfield, North Carolina; Frederick A. Fink of Coronado, California; and many others
.

A free book goes to Richard H. Hopper of Fairfield, Connecticut
.

FRUSTABLE 4:
Why Is Yawning Contagious?

After the publication of
Imponderables
, this question quickly became our most frequently asked Imponderable. And after years of research, it became one of our most nagging Frustables. We couldn’t find anyone who studied yawning, so we asked our readers for help.

As usual, our readers were bursting with answers, unfortunately, conflicting answers. They fell into three classes.

The Physiological Theory
. Proponents of this theory stated that science has proven that we yawn to get more oxygen into our system or to rid ourselves of excess carbon dioxide. Yawning is contagious because everybody in any given room is likely to be short of fresh air at the same time.

The Boredom Theory
. If everyone hears a boring speech, why shouldn’t everyone yawn at approximately the same time, wonders this group.

The Evolutionary Theory
. Many readers analogized contagious yawning in humans to animals displaying their teeth as a sign of intimidation and territoriality. Larry Rose of Kalamazoo, Michigan, argued that yawning might have originally been a challenge to others, but has lost its fangs as an aggressive maneuver as we have gotten more “civilized.”

Several readers pointed us in the direction of Dr. Robert Provine, of the University of Maryland at Baltimore County, who somehow had eluded us. You can imagine our excitement when we learned that Dr. Provine, a psychologist specializing in psychobiology, is not only the world’s foremost authority on yawning, but has a special interest in why yawning is contagious! In one fell swoop, we had found someone who not only might be able to answer a Frustable but a fellow researcher whose work was almost as weird as ours.

Dr. Provine turned out to be an exceedingly interesting and generous source, and all the material below is a distillation of his work. As usual, experts are much less likely to profess certainty about answers to Imponderables than are laymen. In fact, Provine confesses that we still don’t know much about yawning; what we do know is in large part due to his research.

Provine defines yawning as the gaping of the mouth accompanied by a long inspiration followed by a shorter expiration. This definition seems to support the thinking of some who believe the purpose of a yawn is to draw more oxygen into the system, but Provine disagrees. He conducted an experiment in which he taped the mouths of his subjects shut. Although they could yawn without opening their mouths, they felt unsatisfied, as if they weren’t really yawning, even though their noses were clear and were capable of drawing in as much oxygen as if their mouths were open. From this experiment, Provine concludes that the function of yawning is not related to respiration.

In other experiments, Provine has proven that yawning has nothing to do with oxygen or carbon dioxide intake. When he pumped pure oxygen into subjects, for example, their frequency of yawning did not change.

Provine’s research also supports the relationship between boredom and yawning. Considerably more subjects yawned while watching a thirty-minute test pattern than while watching thirty minutes of rock videos (although he didn’t poll the subjects to find out which viewing experience was more bearable—we wouldn’t yawn while watching and listening to thirty minutes of fingernails dragged across a blackboard, either). Did the subjects yawn for psychological reasons (they were bored) or for physiological reasons (boredom made them sleepy)?

When Provine asked his students to fill out diaries recording their every yawn, certain patterns were clear. Yawning was most frequent the hour before sleep and especially the hour after waking. And there was an unmistakable link between yawning and stretching. People usually yawn when stretching, although most people don’t stretch every time they yawn.

Yawning is found throughout the animal kingdom. Birds yawn. Primates yawn. And, when they’re not sleeping, fish yawn. Even human fetuses have been observed yawning as early as eleven weeks after conception. The child psychologist Piaget noted that children seemed susceptible to yawning contagion by the age of two. It was clear to Provine that yawning was an example of “stereotyped action pattern,” in which an activity once started runs out in a predictable pattern. But what’s the purpose of this activity?

Although Provine is far from committing himself to an answer of why we yawn, he speculates that yawning and stretching may have been part of the same reflex at one point (one could think of yawning as a stretch of the face). Bolstering this theory is the fact that the same drugs that induce yawning also induce stretching.

The ubiquity of yawning epidemics was obvious to all the people who sent in this Imponderable. Provine told
Imponderables
, “Virtually anything having to do with a yawn can trigger a yawn,” and he has compiled data to back up the contention:

• 55% of subjects viewing a five-minute series of thirty yawns yawned within five minutes of the first videotaped yawn, compared to the 21% yawn rate of those who watched a five-minute tape of a man smiling thirty times.
  
• Blind people yawn more frequently when listening to an audiotape of yawns.
  
• People who read about yawning start yawning. People who even think about yawning start yawning. Heck, the writer of this sentence is yawning as this sentence is being written.
  

If we are so sensitive to these cues, Provine concludes that there must be some reason for our built-in neurological yawn detectors. He concludes that yawning is not only a stereotyped action pattern in itself, but also a “releasing stimulus” that triggers another consistently patterned activity (i.e., another yawn) in other individuals. Yawns have the power to synchronize some of the physiological functions of a group, to alter the blood pressure and heart rate (which can rise 30% during a yawn).

Earlier in our evolution, the yawn might have been the paralinguistic signal for members of a clan to prepare for sleep. Provine cites a passage in I. Eibl-Eibesfeldt’s Ethology, in which a European visitor to the Bakairi of Central Brazil quickly noted how yawns were accepted behavior:

If they seemed to have had enough of all the talk, they began to yawn unabashedly and without placing their hands before their mouths. That the pleasant reflex was contagious could not be denied. One after the other got up and left until I remained…

Yet, Provine is not willing to rule out our evolutionary theory either. Perhaps at one time, the baring of teeth sometimes apparent in yawning could have been an aggressive act. Or more likely, combined with stretching, it could have prepared a group for the rigors of work or battle. When bored or sleepy, a good yawn might have revivified ancient cavemen or warriors.

So even if Dr. Provine can’t yet give us a definitive answer to why yawning is contagious, it’s nice to know that someone out there is in the trenches working full-time to stamp out Frustability. If Dr. Provine finds out any more about why yawning is contagious, we promise to let you know in the next volume of Imponderables.

Submitted by Mrs. Elaine Murray of Los Gatos, California. Thanks also to Esther Perry of Clarks Summit, Pennsylvania; Julie Zumba of Ocala, Florida; Jo Ellen Flynn of Canyon Country, California; Hugo Kahn of New York, New York; Steve Fjeldsted of Huntington Beach, California; Frank B. De Sande of Anaheim, California; Mark Hallen of Irvington, New York; Raymond and Patricia Gardner of Morton Grove, Illinois; Jim White of Cincinnati, Ohio; Renee Nank of Beachwood, Ohio; and many others
.

A free book goes to Christine Dukes of Scottsdale, Arizona, for being the first to direct us to Dr. Provine
.

FRUSTABLE 5:
Why Do We Give Apples to Teachers?

This Frustable has remained remarkably resistant to reasoned replies. Although few readers could supply hard evidence to back their claims, a lot of people sure seemed to think they knew the answer to this one.

Two theories predominated. The most popular answer was the Biblical explanation. In Genesis, the forbidden fruit comes from the tree of knowledge. Although the forbidden fruit is never specified, the apple has over time been given that distinction. As Lou Ann M. Gotch of Canton, Ohio, puts it:

the apple has come to signify knowledge. Perhaps by giving an apple to the teacher our children are admitting that they’re little devils. Or perhaps they are intimating that the teachers could use a little more knowledge.

The second camp traces the custom to early rural America, when teachers were given free room and board but little pay. Students and their families traditionally brought something to contribute to the school and/or the teacher, be it wood for a fire or fruit for consumption.

But why an apple? As Georgette Mattel of Lindenhurst, New York, points out, apples were cheap and plentiful. Donald E. Saewert adds that the apple is the only fruit that can be stored for long periods of time without canning. In the winter, it might have been the only fresh fruit that was available in many areas. And Ann Calhoun of Los Osos, California, closes this argument with an impressive volley: “Sure would beat dragging a twelve-foot stalk of corn to school.”

Both of these arguments are plausible but certainly not proven. Two readers sent us evidence of other possible solutions to this Frustable.

Ann Calhoun mentions that perhaps the apple-teacher connection was made up by an illustrator in one of the nineteenth-century illustrated magazines (“Every illustration I’ve seen…includes a very pretty young teacher, a blushing hayseed boy of nine, and a classroom of giggling sniggerers.”) Calhoun speculates that the boy gives the teacher an apple not as a symbol of knowledge but as a symbol of beauty. For according to ancient Greek legend, the highly prized golden apples that grew in the Garden of the Hesperus were awarded for beauty at the Judgment of Paris. Calhoun continues: