Again, we are threatened by attacks that are direct and personal and by dangers that are proximal and imminent, and we tend not to react as much to threats that are indirect and impersonal, and to dangers that are distant and eventual.
Evolutionary psychologists also tell us we react to that which we personally find disgusting. I thought is was odd at first to find moral or esthetic judgements included among our evolutionary imperatives, but then realized that natural selection would reward those who avoided and eliminated unhealthy and unhygienic behavior, while those that engaged in or tolerated unhealthy and unhygienic behavior wouldn't be around in large enough numbers to pass on their genes.
My thinking is this: disgust is our visceral reaction to unhealthy and unhygienic behavior; our conscious mind then rationalizes our disgust as morality and esthetics. "Don't touch that not because I personally find it disgusting - don't touch that because it's immoral to do so (morality)," or "Don't touch that because it looks bad if you do (esthetics)."
Obviously, not everybody finds the same things disgusting or repellent, and conflict begins when we impose our moral judgement on others who don't find the same things disgusting that we do, This might be as good an explanation as any for many phobias, particularly homophobia and xenophobia. Some claim the former is based not on a personal reaction but on a moral imperative, and the latter on cultural instead of individual behaviors.
I also note that, like reaction to direct and personal threats, conservatives tend to react more to perceptions of disgust than do liberals, who generally (although not always) tend to be more tolerant. Based on natural selection, this might imply that conservatives will be more likely to survive and pass on their genes, but I doubt it. I think it actually means that conservatives are less able to control their visceral reactions and to believe the rationalizations they tell themselves about morality and esthetics.
Liberals, on the other hand, appear more capable of examining their reactions, tempering their judgement, and evolving on the issues.