The latest study looked at 255 women with breast cancer and compared their answers in a questionnaire on mental outlook and life events with 367 healthy control subjects.

BBC: Positive thinkers 'avoid cancer'

When mental health professionals evaluate perpetrators of violent crimes, they look at relevant defining events and personality traits, he said.

CNN: Insights on why people 'snap' and kill

But the rough is only marginally thicker than at some regular Tour events and winning the Players does not require the same level of skill, high-wire daring and mental endurance that winning a major does.

WSJ: Players Championship: The Major That Isn't Yet Major