Densa

There is no single formal Densa organization; instead, various projects using that name exist as informal groups, usually meant by their founders as a joke rather than a serious organization. Even within Mensa itself, a SIG (special interest group, an informal sub-group of Mensans sharing a particular common interest) has existed for Densa, which, like all Mensa SIGs, required Mensa membership for admission, while it was active.

The concept of an organization for the mentally dense originated in Boston & Outskirts Mensa Bulletin (BOMB), August 1974, in "A-Bomb-inable Puzzle II" by John D. Coons. The puzzle involved "The Boston chapter of Densa, the low IQ society". Subsequent issues had additional puzzles with gags about the group and were widely reprinted by the bulletins of other Mensa groups before the concept of a low