formerly /u/squirrelrampage on Reddit
If anyone wants on deep dive into the topic, I recommend this video essay by Cal Does Life.
And that’s the difference between classical conditioning (the dogs being trained to sensory input by Pavlov) and operant conditioning (Pavlov training himself through his own behavior).
Obligatory footnote: EvoPsych is mostly bunk, deeply intertwined with eugenics and riddled with homophobia, sexism and rape apologia.