Adopting a child isn’t an easy process, but many thousands of would-be parents do the paperwork, sit in interviews, pay the fees, and take the chosen child into their homes with the full expectation that their story will have a happy ending. Unfortunately that’s not always the outcome. For a variety of reasons, adoptions have a significant failure rate. And a Caltech researcher finds clear patterns in which children parents choose to adopt and not to adopt. We look behind the scenes for the reasons why.