Amyotrophic lateral sclerosis (ALS) is a neuromuscular disease that attacks motor neurons until muscle weakness, atrophy and paralysis lead inexorably to death. Victims of this monstrous malady could be forgiven for feeling unlucky.

How, then, can we explain the attitude of the disease's namesake, baseball great Lou Gehrig? He told a sellout crowd at Yankee Stadium: "For the past two weeks you have been reading about the bad break I got. Today I consider myself the luckiest man on the face of this earth." The Iron Horse then recounted his many blessings and fortunes, a list twice punctuated with "I'm lucky" and "That's something."

Clearly, luck is a state of mind. Is it more than that? To explore this question scientifically, experimental psychologist Richard Wiseman created a "luck lab" at the University of Hertfordshire in England. Wiseman began by testing whether those who believe they are lucky are actually more likely to win the lottery. He recruited 700 subjects who had intended to purchase lottery tickets to complete his luck questionnaire, which is a self-report scale that measures whether people consider themselves to be lucky or unlucky. Although lucky people were twice as confident as the unlucky ones that they would win the lottery, there was no difference in winnings.

Wiseman then gave subjects a standardized "life satisfaction" scale, which asks individuals to rank themselves on how satisfied they are with their family life, personal life, financial situation, health and career. The results were striking. "Lucky people are far more satisfied with all areas of their lives than unlucky or neutral people," Wiseman reveals in his charming and insightful book, The Luck Factor (Miramax Books, 2003). Does this satisfied state of mind translate into actual life outcomes that someone might call lucky? It does. Here's how.

Wiseman gave subjects the "big five" personality scale, which measures "agreeableness," "conscientiousness," "extroversion," "neuroticism" and "openness." Although there were no differences between lucky and unlucky people on agreeableness and conscientiousness, Wiseman found significant differences for extroversion, neuroticism and openness.

Lucky people score significantly higher than unlucky people on extroversion. "There are three ways in which lucky people's extroversion significantly increases the likelihood of their having a lucky chance encounter," Wiseman explains: "meeting a large number of people, being a 'social magnet' and keeping in contact with people." Lucky people, for example, smile twice as often and engage in more eye contact than unlucky people do, which leads to more social encounters, which generates more opportunities.

The neuroticism dimension measures how anxious or relaxed someone is, and Wiseman found that the lucky ones were half as anxious as the unlucky ones--that is, "because lucky people tend to be more relaxed than most, they are more likely to notice chance opportunities, even when they are not expecting them." In one experiment, Wiseman had volunteers count the number of photographs in a newspaper. Lucky subjects were more likely to notice on page two the half-page ad with the message in large bold type: STOP COUNTING--THERE ARE 43 PHOTOGRAPHS IN THIS NEWSPAPER.

Wiseman discovered that lucky people also score significantly higher in openness than unlucky people do. "Lucky people are open to new experiences in their lives.... They don't tend to be bound by convention and they like the notion of unpredictability," he notes. As such, lucky people travel more, encounter novel prospects and welcome unique opportunities.

Expectation also plays a role in luck. Lucky people expect good things to happen, and when they do they embrace them. But even in the face of adversity, lucky people turn bad breaks into good fortune. Consider the example set by one of the longest ALS sufferers in history, Stephen W. Hawking, who writes: "I was lucky to have chosen to work in theoretical physics, because that was one of the few areas in which my condition would not be a serious handicap." Unable to move and confined to a wheelchair, Hawking has capitalized on his fate by using it as a chance to transform our understanding of the universe, which he has. That's something.