It's similarly relatively easy to observe several classroom teachers who teach the same subject or grade, and then to assess their basic approach as either serious or humorous, without being able to precisely pinpoint the difference between the two sets of teachers.

Maybe it's best to simply leave well enough alone. The humorist E. B. White suggested that "humor can be dissected, as a frog can, but the thing dies in the process and the innards are discouraging to any but the pure scientific mind."

Laughter, an instinctive contagious outburst that can both bond and humiliate people, is often the result of a humorous comment or situation, but the two concepts aren't really the same. Robert Provine researched the biological and social underpinnings of laughter, and published his findings in a fascinating informative book, discussed in an earlier column, Laughter, A Scientific investigation (2000, Viking).