The situation where an attempted solution has an unintended consequence that makes the original problem worse.

(astrophysics) The effect of solar radiation on an asymmetric asteroid or other small body whereby its rate of rotation increases, potentially leading to the object's eventual disintegration.

(evolutionary psychology) The alleged higher incidence of child abuse and mistreatment by stepparents than by biological parents.

plural of Whitten effect

(biology) The situation where male pheromones stimulate synchronous estrus in a female population.

plural of Coolidge effect

(biology, psychology) A phenomenon in animal species whereby males (and to a lesser extent females) exhibit renewed sexual interest if introduced to new receptive sexual partners, even after cessation of sex with prior but still available sexual partners.

(finance) A hypothetical seasonal anomaly in the financial market where securities' prices increase in the month of January more than in any other month.

(fluid mechanics) The mass transfer along an interface between two fluids due to surface tension gradient.

A perceptual phenomenon where, when the auditory component of one sound is paired with the visual component of another sound, a third and different sound is perceived.