The suggestion here is not that dreams are rehearsing instincts, but that they're rehearsing of behaviors which are important for survival, and the selection of

The suggestion here is not that dreams are rehearsing instincts, but that they're rehearsing of behaviors which are important for survival, and the selection of which behaviors to rehearse depends mainly on what the waking mind is concerned with, since that's a good indicator of "important survival behavior". Hence dreaming about code for those that program all day, or having World of Warcraft dreams after playing too much WoW. Er... not that I've ever done that last. Nope. Not me.