That tension is affecting American family life, Pew found. Fifty-six percent of all working parents say the balancing act is difficult, and those who do are more likely to say that parenting is tiring and stressful, and less likely to find it always enjoyable and rewarding. For example, half of those who said the work-family balance was not difficult said parenting was enjoyable all the time, compared with 36 percent of those who said balance was difficult.

In a 1989 book called “The Second Shift,” the sociologist Arlie Russell Hochschild described the double burden employed mothers face because they are also responsible for housework and child care. Last year she said that despite some changes in society, the workplace had not changed enough to alleviate the problems. In a book last year, “All Joy and No Fun,” the journalist Jennifer Senior described how little had improved: Working parents face similar stresses, but they are now exacerbated by the expectations of modern parenthood and shared by fathers, too.

Of full-time working parents, 39 percent of mothers and 50 percent of fathers say they feel as if they spend too little time with their children. Fifty-nine percent of full-time working mothers say they don’t have enough leisure time, and more than half of working fathers say the same.

Of parents with college degrees, 65 percent said they found it difficult to balance job and family; 49 percent of nongraduates said the same. Pew did not investigate why, but one reason might be that professional workers are more likely than hourly workers to be expected to work even after they leave the office. However, they also tend to have more flexibility during the day.

The survey also found that white parents were more than 10 percentage points more likely to express stress than nonwhite parents. Historically, white and black mothers have been more likely to work outside the home than Asian and Latina mothers, and foreign-born mothers have been particularly likely to stay home, Pew has found.