Does My Baby Miss Me? Separation Anxiety and Object Permanence

Does my baby miss me?
I was asking myself this question while I was at dinner with my husband for our first date night since our son was born. I told myself that he probably didn't realize I was gone - he was too young. But when I got home he was crying really hard and apparently had been for most of the time we were gone. As soon as I took him in my arms, he quieted, and just whimpered for a while before falling asleep minutes after the sitter left. I began wondering if he had missed me/us, or if it was something else. (Perhaps he was teething? I also mused.) So I decided to see if it was possible for him to realize we were gone and be sad from our absence at such a young age (3 months).

From what I found, it seems that most babies do not get separation anxiety until they are at least 6 months old. At around that age, babies develop what is called object permanence, which means that they can remember people and things that aren't visible or present. (Which is why 6-month-old babies get a kick out of "peek-a-boo" but younger babies do not). Before object permanence develops, when an item isn't visible, it just doesn't exist to them. They can't remember that they were playing with their toy giraffe only minutes before; if they aren't looking at it, they aren't thinking about it. For babies under 6 months of age, they literally practice "out of sight, out of mind."
 

Before object permanence develops, his toy giraffe only exists when it's visible to him.

How do I know when my baby has developed object permanence?
First signs of the development of object permanence can be seen when your baby looks around for an object that he dropped or that you took away.

How long does separation anxiety last?
During the second half of baby's first year (months 6-12) is the first peak of separation anxiety. There is another peak during the second half of the second year (months 18-24), though some babies experience them back-to-back for about an 8-month stretch of separation anxiety.

Not all babies will experience bad separation anxiety, though most babies will have at least one bout of it as part of a healthy development. Some babies and toddlers can experience debilitating separation anxiety and develop Separation Anxiety Disorder. But there are steps you can take to make separations less stressful for you and for your little one - but I won't go into those now.

As sweet as it was to think my boy missed me (even though it was heartbreaking hearing him cry like that), I don't think that's what it was. He's a pretty advanced little boy - rolled over for the first time before he was even 2 months old (though he didn't repeat it until he was 3 months), can hold his own weight on his legs (but can't balance enough to stand unsupported), and can almost sit up unsupported - but I think it's a bit early to assume he's developed any object permanence or is capable of experiencing separation anxiety. Although... I did just put a toy in his line of vision, got him smiling, then whipped it away too fast for his eyes to follow... and he seemed to look around a little for it.

If you look at forums, you will find lots of moms that swear their 3 or 4 month old baby missed them when they left, but there is yet to be any scientific research that indicates that an infant that young can experience separation anxiety. Just because your baby cries when you're gone doesn't necessarily
mean that they miss you (sorry!).  But if they have a toy in their hand, keep an eye out when they drop it. If they look around, wondering where it went, then object permanence has started developing, and it won't be long before they do start to miss you.

Heidi Murkoff: What to Expect the First Year
Dr. Greene: Separation Anxiety A-Z
Baby Center: Separation Anxiety