Excerpt from the article:
What Do We Know about Tourette's?
Scientific American
July, 2009

Tourette’s disorder is the subject of popular misconceptions; we’ll examine the four that are most widespread.

Misconception 1:
All Tourette’s patients curse.

In a survey of undergraduates by University of San Diego psychologists Annette Taylor and Patricia Kowalski, 65 percent endorsed this view. In fact, coprolalia, the use of curse words, and copropraxia, the use of obscene gestures, occur in only a minority—probably about 10 to 15 percent—of Tourette’s patients.

But because these symptoms are so dramatic, they plant themselves firmly in observers’ memories. They also garner the lion’s share of media attention, as in a 2002 Curb Your Enthusiasm episode featuring a chef with Tourette’s disorder, who curses uncontrollably in front of his customers.

Misconception 2:
Tourette’s symptoms are voluntary.

Because Tourette’s sufferers can often suppress their tics for brief periods, some have concluded mistakenly that patients generate them of their own accord. In fact, they have little or no control over premonitory urges and can inhibit tics only for so long, just as you can only briefly avoid scratching an itch. Moreover, tic suppression typically results in a later “rebound” of tics.

Misconception 3:
Tourette’s *disorder is caused by underlying psychological conflict.

As medical historian Howard Kushner, now at Emory University, noted, the idea that Tourette’s results from deep-seated psychological factors held sway in American psychiatry for much of the 20th century. As recently as the mid-1980s, one of us (Lilienfeld) was told by a psychologist in training that the tics of Tourette’s patients represented symbolic discharges of repressed sexual energies.

Today we know that the disorder is substantially heritable. A 1985 study by R. Arlen Price, then at Yale University, and his colleagues found that in identical twins (who share virtually all of their genes) with Tourette’s, both twins had the disorder 53 percent of the time, whereas in fraternal twins (who share half their genes on average) with Tourette’s, both twins had the disorder only 8 percent of the time.

Still, stress can increase tic frequency, so genes are unlikely to tell the whole story. Brain-imaging studies of Tourette’s patients reveal abnormalities in areas related to movement, such as the basal ganglia, a collection of structures buried deep in the cerebral hemispheres.

Misconception 4:
People with Tourette’s are incapacitated by their symptoms.

Many individuals with Tourette’s function successfully in society. Mort Doran, a Canadian surgeon with Tourette’s, manages to suppress his tics while in the operating room; he is also an amateur pilot. Neurologist Oliver Sacks wrote of a jazz drummer who reported that his Tourette’s disorder enhanced his musical performances by imbuing them with energy.

Indeed, some have argued that Tourette’s can be a blessing rather than a curse, perhaps in part because the condition forces people to learn impulse-control skills that few of us acquire. This claim is intriguing but anecdotal. Former National Basketball Association point guard Chris Jackson, who changed his name to Mahmoud Abdul-Rauf, said that his Tourette’s made him focus with laserlike precision on his shooting. He twice led the league in free-throw percentage; during one stretch of play in 1993, he made 81 consecutive free throws.