Why Are the Holidays So Stressful?

'Tis the season to be jolly -- so why are so many of us unhappy during what is supposed to be the most wonderful time of the year?According to a survey by the American Psychological Association, 38 percent of people said their stress level increases during the holidays.Another survey, by the investment firm Principal Financial Group, revealed that 53 percent of people feel financially stressed by holiday spending, even though more than half of the 1,000 respondents had created spending budgets.