High dopamine activities are those that are engineered to pique and hold your interest. Video games, tv, social media, news aggregators, porn, etc.
Our brains are designed to prioritize the most interesting stuff. Back on the Serengeti, that made sense. There wasn’t much novelty, so when you found some, your hardware wanted to ensure that you were able to focus on it long enough to grok it. Will it hurt you? Can you eat it?
Nowadays novelty is ubiquitous. Interesting stuff is everywhere! Learning new things can be pretty interesting, but it will never be as interesting as stuff that’s literally engineered to be interesting.
The solution is to simply (ha!) remove those more interesting but less rewarding options from the equation.
You don’t have to believe me—it’s an easy hypothesis to test. Just quit ALL high dopamine activities, cold turkey, right now. Zero exceptions. In my experience, those relatively boring tasks become attractive again within mere minutes of dogged abstinence from high-dopamine activities.