Daniel C. Dennett, From bacteria to Bach and back:
Darwinian creatures:
"They are born 'knowing' all they will ever 'know'; they are gifted but not learners."
"The merely Darwinian creature is 'hard-wired' ... We can expose its cluelessness by confronting it with novel variations on the conditions it has been designed by evolution to handle: it learns nothing and flounders helplessly."
Skinnerian creatures:
"[They] adjust their behavior in reaction to 'reinforcement'; they more or less randomly generate new behaviors to test in the world; those that get reinforced (with positive reward or by the removal of an aversive stimulus - pain or hunger, for instance) are more likely to recur in similar circumstances in the future."
"The Skinnerian creature starts out with some 'plasticity', some optionality in a repertoire of behaviors that is incompletely designed at birth; it learns by trial-and-error forays in the world and is hard-wired to favor the forays that have 'reinforcing' outcomes."
Popperian creatures:
"[They] extract information about the cruel world and keep it handy, so they can use it to pretest hypothetical behaviors offline, letting 'their hypotheses die in their stead'[.] Eventually thy must act in the real world, but their first choice is not random, having won the generate-and-test competition trial runs in the internal environment model."
"The Popperian creature looks before it leaps, testing candidates for action against information about the world it has stored in its brain somehow."