WASHINGTON — So a scientist walks into a shopping mall to watch people laugh. There’s no punch line. Laughter is a serious scientific subject, one that researchers are still trying to figure out.

I don’t want to sound too somber, but the other day I had to practice how to laugh. “Ha, ha, ha.” This was not a simple giggle at a silly joke. Nor was it even a semi-substantial chuckle at a humorous ...

It was early in our courtship that I realized the guy I was dating, with whom I now cohabit, wasn’t laughing at my jokes. Well actually, he may have been laughing at my jokes, and in fact I thought he ...

Donning a black hat, Tawanda Johnson turns her head slowly, her eyes widening. “Ha-ha-ha-ha-ha. Uhhhh-ha-ha-ha-ha-ha. Ahhhh-ha-ha-ha-ha-ha-ha.” A staccato laugh escapes her mouth, each syllable more ...