In Diamond, they cause. confusion if the user doesn't like dry food. (i think it was dry). There are no tastes in Generation V, so is there always confusion or what?
I'm an idiot. >If held by a Pokémon, it restores the user's HP in a pinch, but will cause confusion if it hates the taste.
It has the exact same effect. And it isn't actually to do with the taste; >Aguav Berry Confuses Pokémon if their nature hinders Special Defense (including Quirky) Figy Berry Confuses Pokémon if their nature hinders Attack (including Hardy) Iapapa Berry Confuses Pokémon if their nature hinders Defense (including Docile) Mago Berry Confuses Pokémon if their nature hinders Speed (including Serious) Wiki Berry Confuses Pokémon if their nature hinders Special Attack (including Bashful)
http://smogon.com/dp/articles/status http://bulbapedia.bulbagarden.net/wiki/Wiki_Berry#Generation_IV