I was interested to come across the concept of ‘carnism’, which is basically the opposite of veg*nism. According to Wikipedia:
"Carnism was coined by social psychologist Dr. Melanie Joy in 2001. Dr. Joy claims that because carnism is a dominant, violent ideology it has remained unnamed and invisible so that meat eating has seemed a given rather than a choice; according to Joy, when eating meat isn't a necessity for survival, it's a choice, and choices always stem from beliefs. Joy maintains that because of the violence inherent in carnism (modern meat production requires intensive and extensive violence toward animals), the system uses a set of social and psychologicaldefense mechanisms to distort people's perceptions and block their awareness and empathy when they eat meat, enabling humane people to participate in inhumane practices without realizing what they're doing.
Joy suggests that carnism exists across cultures where eating meat is a choice rather than a necessity. In meat-eating cultures around the world people tend to find a small handful out of thousands of animal species edible and view the rest as disgusting. According to Joy, though the type of animal consumed may change, the belief system itself does not. And, Joy argues, in modern, meat-eating societies, the species a culture deems edible is not based on logic or economics but simply on conditioning.
Joy distinguishes carnists (those who eat meat) from carnivores—which are animals, human or nonhuman, that need to ingest flesh to survive—and also from omnivores—which are animals that can survive ingesting both plant and animal matter. "Carnivore" and "omnivore" refer to one's biological predisposition, but when eating meat is a choice this behavior is based on ideology, not biology. Joy also says that the term "meat eater" is inaccurate in that it presents the behavior as though it were divorced from a belief system—which is why, for example, vegetarians are not referred to as "plant eaters". Joy also explains that the term "carnist" is meant to be descriptive, not pejorative, just as, for instance, Buddhist, capitalist, or socialist simply describe a person who acts in accordance with a particular belief system.”
This whole page is an interesting read: http://en.wikipedia.org/wiki/Carnism
This just goes to show even more how any one of our actions are choices. While they may seem like natural reactions and reflexes, nearly everything we do is based on a conscious thought process, even if this process occurs so fast due to years of habit that it seems like the natural, necessary, and only way to do it.