I believe with time you learn what's a con - the "I'm gonna cry until they come back because I want something" - and anything more serious.

Remaining patient, putting them back down to go to sleep or whatever, staying patient, and letting them cry on the con games is tough but sometimes necessary.

Flying back last week from a trip a young mid-20s woman had a screamer daughter. Wanted something and didn't get it? Yell-scream loudly. Told no? Yell-scream. Got picked up to be carried off the plane AND into the terminal by mom because she wouldn't voluntarily go and literally screamed off the plane and into the terminal for a good 3-5 minutes.

Lack of discipline, IMO, but at least the mom remained calm and wasn't smacking her around like some do.

Good luck.