Full Idea
Contrary to early behaviourist dogma, associations are not all equally learnable. Rats learn to associate eating with nausea, and a flash with a shock, much more easily than either complementary pairing.
Gist of Idea
Rats find some obvious associations easier to learn than less obvious ones
Source
J Ladyman / D Ross (Every Thing Must Go [2007], 5.2)
Book Reference
Ladyman,J/Ross,D: 'Every Thing Must Go' [OUP 2007], p.267
A Reaction
That looks like an argue for some sort of innate knowledge, but experiments to disentangle eating from nausea must be rather hard to set up.