“Do Female Bonobos Fake Orgasm?” Wolter Seuntjens and Karolina Hansen, Journal of Unsolved Questions, vol. 1, no., 15, 2011.
BONUS: Walter Seuntjens’ earlier masterpiece, “On Yawning; or, The Hidden Sexuality of the Human Yawn“, was published in volume 11, no. 1 of the Annals of Improbable Research. It’s a a specially abridged version of the Ph.D. dissertation which the author defended (successfully!) on October 27, 2004. The related web site www.baillement.com is a lavish compendium of information about yawning.
(Thanks to investigator Martin Gardiner for finding this.)