The practice of living the life in Christ: fasting, vigil lamps, head-coverings, family life, icon corners, and other forms of Orthopraxy. All Forum Rules apply. No polemics. No heated discussions. No name-calling.
I don't think that it's the case that laughter is sinful per se, but rather that it is something which, when indulged in to an excessive degree, it gives rise to occasion of temptation due to the individual allowing his mind to be occupied by frivolities to an unhealthy degree rather than that which is beneficial to his salvation.
St Benedict of Norcia (Nursia) mentions this in his monastic rule. You can view the relevant chapter here.
Laughter is a passion-Christ never laughed so there's the proof.
If you find the list of the passions it's on there and a bunch of other passions too that lead from it. I can't really picture the Saints laughing either.
In Serbian they say, "Ne valya se smiyati, odplakachesh"
"It's not good to laugh because later you will cry."
