>>13222186Well in rats at least, they can specifically breed for laziness or physical activity. I can't even locate studies on Google Scholar that have looked into it in humans, in fact that's the only animal study I'm aware of. I've seen statements that laziness isn't innate, but nothing to back it up. I'm sure environment plays some part, and ingrained habits can push a person in one direction or another, but knowing certain people who are basically "on" and working 16 hours a day, and knowing others who can't seem to get anything accomplished, makes me think there's probably some genetic or epigenetic factors at play as well.
https://doi.org/10.1007/s12035-018-1171-0
