Babies do a lot of cute stuff in their first year. But that awkward little flappy move that means they’re saying hello or bye-bye takes the cake.

In addition to being so stinking cute, it’s one of the first signs that your baby is becoming a sociable human, interested in participating in one of the world’s most universal greetings.

And once a baby learns how to wave, it’s basically game over: They know it gets a big reaction — from you, from Grandma, even from the random person in the drive-thru lane. Pretty soon, half their day will be spent waving at anyone, anytime, anywhere.

But when does your baby go from confused-about-the-world caterpillar to socially outgoing butterfly? Here’s when you can expect your baby to start waving, along with what it means about their development and what comes next.

Most babies start waving around 9 months old, though some will do it a little earlier and some a little later.

There’s actually research suggesting that “imitation skills,” like waving, may be tied to your baby’s weight at birth. Case in point, a 2013 study suggested that babies with a very low birth weight were slower to master waving than full-term babies.

Whenever your baby starts waving, it probably won’t look very sophisticated in the beginning. Your baby may just flap their arm up and down, curl their fingers into a fist, or simply rotate their wrist.

With a little practice, though, all those random movements will eventually turn into a unique wave that reflects your baby’s personality.

If your baby is getting the hang of their motor skills in other ways, you can begin showing them how to wave. These other skills might include:

Most babies will pick up this milestone just by watching others wave and then trying to imitate it. You can also help baby out by gently waving their hand for them when greeting or saying goodbye to someone.

Make sure you pair the motion with a verbal cue, so your baby learns that the words “hi” or “hello” and “bye-bye” or “goodbye” mean it’s time to start waving!

Well, gross motor skills, for one — being able to make their bodies do what they want in a coordinated way is an important milestone for babies. And it’s one that seems like it should be easy but still takes some practice!

There’s also some hand-eye coordination involved, though less than there is with clapping and pointing.

Finally, there’s nonverbal communication. It may be several more months until your baby starts talking, so finding ways to communicate with body language is hugely important to your baby’s development and overall sense of happiness.

Other hand movements, like clapping and pointing, often go along with waving. Typically, waving happens first, but it’s no big deal if your child claps first and then starts waving a few weeks later.

Your baby may also be able to:

  • transfer objects from one hand to another
  • grab onto things while being carried
  • pound, slap, smack, and bang objects (yes, highchair time can get loud!)

At this age, your baby may also start:

  • sitting up unassisted
  • bearing weight on their legs with your help
  • crawling or rolling their way across a room

In other words, if you haven’t babyproofed yet, now is the time.

If your baby is meeting other common milestones for their age but isn’t waving yet, it’s probably not a cause for concern. It just means the little switch in their brain that connects “hi” or “bye-bye” to a waving hand motion hasn’t been flipped yet.

Don’t worry — it will happen! But only when your baby is ready.

Meanwhile, keep imitating waving and giving them a physical assist when appropriate to encourage the connection.

Again, one delayed milestone typically isn’t cause for concern. But if your baby is missing multiple milestones, it may be time to talk with your doctor.

An 8-month-old baby who doesn’t wave and can’t roll from side to side, sit up unassisted, or reach for objects — or one who appears to have low muscle tone or excessively tight muscles — may have a gross motor or neurological condition.

Similarly, if your baby can’t wave yet and also shows signs of a social-communication delay, they could have a developmental disorder.

This type of delay might show up as a baby who doesn’t:

  • smile socially
  • seek attention or affection
  • engage in any kind of babbling

This shouldn’t be the first thing you assume if your little one is around 8 months old and not yet waving. However, if not waving is one part of a larger picture of delays, concerns, or atypical behaviors, it’s wise to get professional input.

It’s important to attend all recommended well visits, so your pediatrician can monitor baby’s development.

Once your baby starts waving, it’s a sign that they’re about to make leaps and bounds in their gross motor skills — and their social development, too!

All babies meet milestones on their own time, but you can safely assume that your baby will probably start doing the following things sometime in the next few months:

  • pulling themselves up to stand
  • changing positions (from lying down to sitting up, sitting to crawling, etc.) on their own
  • feeding themselves finger foods
  • cruising around the room
  • saying “Mama” or “Dada”
  • showing signs of separation anxiety
  • dropping naps or sleeping through the night

Waving is often an early sign that your little baby is inching closer to becoming a toddler: They understand social cues and have the gross motor skills to show them off!

All babies move at their own pace, but many babies start showing off a “hello” or “goodbye” wave around 7 or 8 months.

If your baby hasn’t waved yet but is meeting their other milestones, give it time and keep practicing — they’ll get there. And once they start, you won’t be able to stop them!