Shows stranger anxiety
What is this milestone?
Becomes clingy with familiar people, shy around strangers
Stranger anxiety is a completely normal developmental phase where your baby may become fussy, clingy, or fearful around unfamiliar people, even if they were previously outgoing and social.
Why it matters
While it can be stressful for parents and well-meaning relatives, it is actually a sign of healthy cognitive and emotional development. It means your baby clearly differentiates between their primary caregivers and strangers, showing strong, secure attachments.
What to expect leading up to it
A baby who used to happily go to anyone might suddenly cry or hide their face when approached by a new person. This reaction can vary in intensity from mild wariness to full-blown distress.
How to encourage and support it
Validate their feelings and offer physical reassurance by holding them close. Don't force them to go to a stranger. Instead, let them observe the new person interacting warmly with you first, giving them time to warm up at their own pace.
When to talk to your doctor
The CDC's milestone checklists say what most children (75% or more) can do by each age. They list “Is shy, clingy, or fearful around strangers” by 9 months. If your child is not doing this by then, the CDC's advice is not to wait: talk with your child's doctor, share your concerns, and ask about developmental screening. The same goes at any age if your child loses a skill they once had, or if anything else about their development worries you. Source: the CDC's “Learn the Signs. Act Early.” milestone checklists, checked October 5, 2026.
Every child develops at their own pace, and the ages here are the CDC's general guidance — not a developmental screening. This article is not medical advice and is not a substitute for your pediatrician. If you have any concern about your child's development, talk to them.
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