Which developmental milestone must be reached before an infant experiences separation anxiety?

s a newborn, your baby has no sense of herself as an individual: She thinks that the two of you are one and doesn't realize that the tiny hands and feet waving before her are her own.

Over time, though, as your growing baby develops physically and mentally, she'll gradually figure out that she's her own little person, with her own body, thoughts, and feelings. Of course, she'll also want to do things her own way.