It's especially fortunate that the friction between the generations is decreasing, because they are increasingly spending more time together, both in the workplace and in the home.

Two months ago in Trends, we discussed how businesses will be affected by the challenges and opportunities of managing workers of different generations who will be working side by side. This month, we are focusing on the impact of adult children who are not quite ready for adulthood.

As we've already noted, it's a different world than the one in which the Boomers were raised. The members of that generations were expected to grow up with their parents, finish high school or college, get a job, get married, and go start their own household, all by the age of 22.

For roughly the past 15 years, more and more young Americans have been refusing to take on the responsibilities of adulthood. They move in and out of their parents' homes, switch careers, and take longer to get married, have children, or buy homes. Let's examine the facts behind this trend and some of its implications.

According to a survey by the National Opinion Research Center at the University of Chicago, the age at which most adults believe a person has reached adulthood is 26. By that age, the respondents said that an individual should have taken the "seven steps toward adulthood."

These steps, in declining order of importance, are:

1. Completing one's education.
2. Being employed full-time.
3. Supporting a family.
4. Being financially independent.
5. Living independently of one's parents.
6. Being married.
7. Having a child.

By this standard, a growing number of young people are not becoming grown-ups. This new trend was identified in a report by the British think-tank the Social Market Foundation for a personal-products division of Lever Brothers.

The report found that one of every four 20- to 24-year-olds move back into their parents' home at least twice for long periods, before finally establishing their own home. One in three returned home for about three months, with another one in three staying up to nine months. However, nearly 10 percent returned for two years or more.

But this group of "boomerang kids" is independent compared to a startling 56 percent of young men and 38 percent of women in the 20- to 24-year-old...