I agree with Tejas’ comment, particularly the second point. As a social psychologist, cognitive dissonance is exactly what I would cite too. Reducing the disparity between attitudes and behaviour by any means (such as increasing plant-based eating for health reasons) leaves the mental space to either learn about moral reasons without the same degree of defensiveness OR—even better and fairly likely in my opinion—start adopting moral reasons without even any external influence. At least in western societies, the moral reasons for going vegan are pretty well-known, so motivated reasoning may work in our favour over time. Reducetarians may look at their behaviour and “decide” subconsciously that it was partially motivated by moral reasons because that makes them feel like a good person… which then encourages them to make further changes on moral grounds.
I agree with Tejas’ comment, particularly the second point. As a social psychologist, cognitive dissonance is exactly what I would cite too. Reducing the disparity between attitudes and behaviour by any means (such as increasing plant-based eating for health reasons) leaves the mental space to either learn about moral reasons without the same degree of defensiveness OR—even better and fairly likely in my opinion—start adopting moral reasons without even any external influence. At least in western societies, the moral reasons for going vegan are pretty well-known, so motivated reasoning may work in our favour over time. Reducetarians may look at their behaviour and “decide” subconsciously that it was partially motivated by moral reasons because that makes them feel like a good person… which then encourages them to make further changes on moral grounds.