Once they were grown up, baby boomers were way too cool to move back in with their parents. So why do Boomer parents welcome their kids back into the nest? Social psychologist Jane Adams, author of When Our Grown Kids Disappoint Us, and authors Tamara Erickson (Plugged In: The Generation Y Guide to Thriving at Work) and J. Walker Smith (Generation Ageless: How Baby Boomers Are Changing the Way We Live Today) explain this phenomenon.