Against CIO, told it's because I am a first time mommy?

You are against CIO because you are a good mommy. It goes against every natural mothering instinct. It has bee proven that CIO is very dangerous to a child's emotional health and can possibly raise the risk of SIDS. What it teaches is that no matter how hard they try to get mommy's attention that mommy can't be bothered to tend to their needs. Just because we may think all their needs are met ie, fed, changed, burped, etc, doesn't mean they don't have a need. As a human babies need human contact. I wonder if your in-laws ever cried themselves to sleep. I have, and it is a horrible feeling. You don't get a good rest and often wake up miserable. I have heard that Dr Ferber (the father of the CIO movement) had no relationship with his adult children. I wonder why? Give your children the love and attention they deserve and they will grow up secure and emotionally healthy.