In regards to eating meat

[yossarian]

perhaps cognitive dissonance theory would explain it.

People feel dissonance between the belief that they like animals and would never hurt them, and the behaviour of killing billions of animals. The way to resolve the dissonance w/o changing behav is to assert how much they enjoy the horror and plan to continue. The re-commitment to the behaviour is strengthened, and so their mind is able to more quickly resolve the dissonance. It suppresses the thoughts regarding the killing of animals & alleviates the anxiety. The reduction in anxiety reinforces the behaviour and people learn to just fantasize about bacon everytime a nearby vegetarian arouses awareness of the underlying conflict. By publicly committing to their behaviour, the mind is put under extra pressure to resolve the dissonance, in accord with the commonly understood social pressure effect where making a public social commitment can motivate people to stick with that commitment and making a public choice can motivate people to stick with that choice so that others do not look down on them for being wishy-washy.

This might be the case in some situations, but it seems to me that the biggest culprits in the "mmmm bacon!" expressions seem to be people who have no problem hurting/eating animals, and not the ones who are "wishy-washy." I agree with the cognitive dissonance idea, but the dissonance probably isn't always caused by their belief that they'd never hurt animals.

This is not inline with psychodynamic theory.

Psychologists have shown that often people who appear the MOST commitment to some particular lifestyle are actually the most borderline, and their extreme commitment is an overreaction.

Someone who was not threatened at all by a vegetarian would not think of rubbing it in their face, their expression would be neutral, it would be like meeting someone with a different hair color.

The people with the emotional reactions are the ones who are going to make a strong response, and so my theory is that the people who have to engage in these defence mechanisms are actually people who hear the message of the vegetarian.

When it comes to rednecks and the like, these are generally people who really do love animals.

The other factor your have is how the eating of meat fits into a general macho identity. Many men these days feel insecure in their masculinity and so take on an overcompensatory macho identity. They make a point of pointing out how hard and badass they are, how they dont care about peoples feelings, how they love red meat, etc. But the guys who actually say this are just insecure people, while those truly comfortable in their masculinity feel no need to constnatly assert it (though it can still be observed behaviourally and emotionally of course)

I've often found that men who go to great lengths to present a macho image are very submissive and feminine in relationships, and generally mama's boys. They are compensating. In comparison, the men who are the most masculine by nature often try to cultivate more femininity--because harsh masculinity is not socially graceful and they suffer social consequences for their natural brutishness.

The most socially adept men these days are extremely feminine, while the most masculine men are complete loners who are feared and detested. Inline with this reality, it is the socially adept men who engage in image-oriented overcompensatory macho behaviour while the loners still engage in masculine behaviour but instead of that behaviour being compensatory it is a firm impulse that permeates all aspects of their life, not only finding expression in a few image-oriented aspects.

What I'm saying is that the people who say stuff like that to vegetarians are the people who feel bad about their own meat eating--these people are on the fence on some level. The people who feel no emotional reaction to the vegetarian message, on the other hand, will not engage in this childish behaviour but also have no chance of ever adopting vegetarianism.