“There's a sort of sibling moratorium when you're establishing yourself as an adult. So much of your energy has to be focused on other things like work and kids. But when people become more settled, siblings tend to regroup because now you're building a new extended family.”

American magazine editor and author

Jeffrey Kluger is an American magazine editor and author. He is editor at large at Time magazine and has written thirteen books across a range of subjects. His books include works on psychology, medicine, family dynamics, and spaceflight, among them The Narcissist Next Door, Splendid Solution: Jonas Salk and the Conquest of Polio, The Sibling Effect, and Lost Moon: The Perilous Voyage of Apollo 13. Lost Moon later served as the basis for Ron Howard's film Apollo 13. He has also written two young adult novels and one novel for adults, Holdout.