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.

(biology) A phenomenon concerning the suppression or prolongation of estrous cycles of mature female mice (and other rodents), when females are housed in groups and isolated from males.

(psychology, sociology) The phenomenon in psychological and sociological research that people seem to associate more positive attributes with women in general than with men in general, reflecting an emotional bias.

(organic chemistry) The effect of geminal substituents on the reactivity of the carbon atom to which they are attached