No, it's not possible to spoil an infant in the first year. This is a tender time when getting to know, love, and understand your baby takes over your life and priorities. While there's some proof that very screamy babies (those who cry more than three hours a day) may do better if given a few minutes to console themselves, responding promptly is not only a strong parental instinct but also the best thing for your baby, and it can actually decreasing crying time later on.
Originally published in Child magazine, February 2005. Updated 2009.