Baby laughs?

Brooke

Just curious as to when your babies started full on chuckling and belly laughing, mine started at 8 or 9 weeks and has been doing it ever since

But on the bounty apps and other <a href="https://play.google.com/store/apps/details?id=com.glow.android.baby">baby apps</a> they say that that comes at 4 months? I'm sure that's wrong so I'm curious as to when your little ones started!