cannibalism is simply the act of eating flesh of your same kind. the connotation that it also implies a barbaric, tribal, and bloody nature is a separate entity.
A person forced to resort to cannibalism to survive can't be compared to another person that, aside from eating the flesh of their victims, also enjoys torturing them.
Ergo, the cannibalism trait is misleading, but only because the pop-culture interpretation of cannibalism also implies enjoyment. A pawn in rimworld that ate a human burger and got the negative thought is technically still a cannibal. a pawn that doesn't know he's eating a meal made with human flesh is also a cannibal. what kind of society/culture they came from will ultimately define how they react. Adding that kind of depth to rimworld is almost certainly not high on the priority list if it exists at all.
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Various traits:
Vegetarian: Gains a minor +thought when eating raw non-meat food & non-meat simple meals. Gets very upset when eating anything with meat in it, neutral stance on rations. will eat lavish and fine meals as a 2nd-last resort. will eat meat as a last resort.
Meat Eater: Gains +thoughts when eating food with meat in it. gains -thoughts when eating meals without meat in them. Eating raw meat has a reduced negative effect.
Asthmatic: dislikes dirt, loves cleanness. Looses breathing effectiveness after walking for a while, requiring regular rests. can get an asthma attack which can be alleviated with medicine.