While it’s gut-wrenching to see your little one upset, it’s actually a sign of a secure attachment, says Sarah Rosensweet, a parenting coach in Toronto. That’s because between 4 and 7 months babies begin to realize that people and objects exist even when they can’t see them. This is called object permanence. At certain stages, most babies or toddlers will show true anxiety and become upset at the prospect – or reality – of being separated from a parent. Yes, to a degree.
Separation anxiety in infants often starts between 8 and 14 months old.

For many babies, separation anxiety starts at around 8 months of age, but you may start seeing indications of separation anxiety in your baby as early as 4 months. Separation anxiety often features full-on sobbing, epic fussing and difficulty consoling your baby when you’re out of sight. It can rear its head when you're dropping your baby off at daycare —or when you're simply going to the bathroom. Separation anxiety is a normal stage of emotional development that starts when babies begin to understand that things and people exist even when they're not present – a concept called object permanence. “It’s healthy, good and normal,” she says.