Ronald Reagan swore he had none. George W. Bush had a headful, and so did Bill Clinton -- of gray hairs, that is.
Now, President-elect Barack Obama, a day away from taking the nation's most demanding job, already shows a sprinkling of those pesky white streaks in his first official portrait, which was unveiled last week.
At 47, Obama is nearly a decade younger than his predecessor when he took the oath of office, and seems too cool and fit to let the looming presidency stress him out.
"The gray is coming quick," he reportedly said last July. "By the time I'm sworn in, I will look the part."
President Reagan famously denied that he ever dyed his lustrous locks. President Clinton's trademark shock of white followed him through two terms. And President Bush visibly aged from his first inaugural through the trauma of 9/11 and two unpopular wars.
Most medical experts say that genetics plays the largest role in determining when a person goes gray, but new research seems to back the old wive's tale that stress, indeed, can turn the head white, or at least gray. Some researchers say persistent mental or physical stress that lasts two or more years can cause premature aging of the hair.
The French say Marie Antoinette turned gray overnight when she awaited her fate with the guillotine -- a legend that at least one doctor said likely had a medical explanation. Anxiety may have made her hair temporarily fall out in a condition called telogen effluvium, leaving the pale villus -- or "baby hair" -- behind.
Obama's race for the White House was the longest in history -- nearly two years -- and many, such Dr. Anthony Gaspari, have noticed a graying around the president-elect's temples. And with an economic crisis and international conflicts at full throttle, more stress is on its way.
But, Gaspari said, "In Obama it looks genetic."
"There's a common garden variety graying of hair that is a gradual process from the death of cells on the hair follicle," Gaspari, a dermatologist from the University of Maryland Medical Center, told ABCNews.com.
"Maybe when he was on the campaign trail he was dying his hair and now that he's elected he doesn't care so much or has less time or wants to look the distinguished leader mode, rather than the young upstart and man for change," he said.
But one researcher who has studied gray hair and its causes claims Americans are going gray five years earlier than they did in 1970 -- and probably because of stress.
"Basically, people gray as they grow older," said osteopath Tyler Cymet, vice president of medical education at the American Association of Colleges of Osteopathic Medicine who practices at Northwest Hospital outside Baltimore. And Obama is right on target, age-wise.
The average white male goes about 30 percent gray at the age of 34, "give or take nine years," Cymet told ABCNews.com. African-Americans hit the 30 percent gray mark at 44 years old, plus or minus 10 years.
After the head turns 30 percent gray, it is another two to seven years until a person is fully gray. About 50 percent of all people are graying by 50. Obama is three years away from that age.
"With President Obama having a white mother and an African-American father, he would fit in the middle of the two groups," Cymet said.