What does "I love to laugh" mean?

I see this on various dating/singles sites. Just about 100% of the time these are written by women – I don’t think I have ever seen that phrase written by a guy (but to be fair, I don’t usually read profiles from guys).

So what does it mean?

That she has a reputation as a crabby bitch and she wants to dispense with that from the start?

That she moonlights as a standup comedian or a clown?

That she’s an airhead and is incapable of deep understanding?

I’m serious in this question: when some describes themselves with the phrase “I love to laugh” – what is the message?