Hmm, so you're saying being aggressive is natural, but you also believe our behaviour is influenced by the foods we eat? So what would be different according to you when people ate natural foods, then (regarding behaviour)?
People would be less agitated by bodily stressors such as lack of certain nutrients on a better diet. They would also be less agitated by bodily stressors from addictive chemicals or anti-nutrients in bad diets because the bad diets would be gone...
And why is it that people and animals are aggressive in your view? What does it bring them that makes it worth endangering injury, and thus their own self preservation?
people and animals become aggressive because aggressiveness is just the heightened pursuit of what animals/people want, and sometimes this form of going after what an animal/person wants makes logical sense, such as when you want to retaliate when someone hits you, or an animal needs to kill something to eat, or for territory acquisition, or for mating competitions... the list goes on. It brings them a reward, and regarding endangering self preservation, normal healthy animals and people don't have the stand-offish types of danger assessment you're implying, for instance cubs play together and wrestle even though they could poke an eye out and cause severe pain, people cut off people in traffic even though it could cause an accident, so could talking on the phone, or opening some mail is dangerous because of potential anthrax, or walking outside because a meteor could hit them.. risk is in everything, which is why we don't naturally develop paranoid behavior unless pushed by stressors. Generally, people and animals only use aggression when the benefit outweighs the risk, such as, cutting someone off isn't that risky because it's just as likely someone isn't paying attention and rams into you as it is you cutting someone off and them getting angry or not paying attention and crashing into you, or that the risk of being seen as socially inadequate in a mating competition amongst animals is a greater risk (no reproduction) than risking your life in the match... If animals and people weren't driven to risk things in this way, we would still be far back on the evolutionary scale.
Again, I emphasize we are selfish by nature. Animals included (and yes, it's in the pack leader's best self interest to put the pack's interest first. It would have been more clear if I said he/she is not pursuing his/her own short term interest). But, again, aggression is something different in my view.
It's a very basic principle of selfishness to be long term, for instance if charitable activities only made people feel good for a few seconds, then everyone forgot about them and it was socially normal to think of it as no big deal, there would be a lot less charity. Instead, it stays with people for a long time and is therefore more of a reward. The same with animals, if they can prolong their life substantially longer by thinking for a group, it's a no brainer for them.
The comparison you made (a fleeing herd and car drivers on a highway) is far stretched in my view. You are not fleeing, you are probably just incapable of dealing with stress in traffic when you behave that way. And you do have a choice.
It's the only real comparison that can be made between animals and a modern human situation of highway driving... The relation between the two wasn't about the fleeing, but about the priority of who gets where first. The animals are trying to reach safety, because that's whats important to them in that situation, and I'm trying to reach my destination whether it be work or school, because that's what's important to me in that situation. Both parties are willing to put themselves first, me and the animals, because it makes the most sense. The stakes are different, but it doesn't change the logic. The stress in traffic has nothing to do with it for me, although I'm sure it is so for many people, I simply am stressed about being late, and I'm not incapable of dealing with it, I just choose not to if I have the opportunity... The animals also have a choice to not run and just be eaten, just as I have a choice not to cut someone off, the stakes are higher but it doesn't change the logic. Just as 2+2=4, so does 2+2+2+4=10, it's a higher degree, a different situation, but the logic remains the same. For instance if you could murder someone with a million dollars in their hands and get away with it, many people would, if you lowered it to 500,000$, less people would because of less reward, but the logic is still there, if you lower it to $1, almost no one would because the effort of murdering someone, the guilt, etc, is not worth the reward. To most people, getting to work on time may not be as important, but I can get away with it and I value it as enough to let someone else dislike me for a few minutes, and the logic is the same.
It's not like you are forced to cut of someone or else you get killed (on the contrary). Survival of the fittest doesn't apply here.
As we have already covered, self preservation isn't the only driving force behind animal and human actions, for instance, there is also self-advancement, or stress release, or any gain of some kind, or prevention of any kind of loss. An example of this in the animal world that happens often is in a pack of animals, often the most dominant animal will take the largest share of a kill, like in lions, even if he didn't kill anything or provide any service except being the strongest to stand up to. He doesn't 'need' the extra food, but it does give him an edge to stay full longer, to build stronger muscles, etc.
To me it seems like you have found yourself a reason why you do what you obviously feel like doing. You can't help it, it's in your nature, right?
As everyone does everything for some sort of reason, this is technically correct. However, this action I 'feel' like doing isn't just because I feel it but because it makes logical sense, and doesn't hurt any of my moral beliefs. If I just found reasons to do what I felt like doing and for no other reasons I would probably be in jail by now, as would any person that wasn't taught to control their feelings at a young age. What you're implying though is that anyone can be rude and make up excuses that it's in their nature and that's not right by you, and while I agree with that, I've been showing you that the example of cutting people off to get to work on time is not an intrinsically rude behavior, as the motive isn't rude. It's perceived as rude yes, in a perfect world would it be O.K? No. Do we live in that kind of world? No. Like I said, it's still a limited resource, dog eat dog world, and I don't need to make excuses for doing what is logical, I just need to have logical reasons. The logical reason for cutting people off on the road when I'm late is this:
It's not harming anyone past psychological, temporary stress, maybe.
It's relieving my stress, and self-advancing behaviour.
It's not going to give me any kind of loss.
It's not going to give a substantial loss to society.
Therefore there's no reason not to. So why don't I do it when I'm not late?
There's no need to make another persons day worse if you're not going to gain from it.
If there was, you would have to morally balance the loss/gains, obviously they are equal to you and the other person, so who is more important to you? In any logical person, you are number one... And yes I know it's extremely common for people to think of themselves secondarily, and I think it's pretty sad for their interests, but great for everyone else. Most of these people ride a high horse though pretending they are (arrogantly) better than the honest selfish people because they make sacrifices, when really it's the stupid option according to nature. Sacrifices according to nature are only logical when it benefits everyone and yourself, such as inventing a solar power harnessing device. You benefit from sales or press or what have you, and society does. But letting people cut in front of you in line to maybe make you late or whatever, while it gives you an emotional paycheck, in the eyes of logic it's the same as taking a bullet for a poor innocent child to save their life. You feel good yes, for a while, but in the long run the physical benefit is for the person you sacrificed for and you're the sucker. It's kind of a phenomenon how all the smart people in the world have set up things for people to be generous while the greedy take all the wealth and don't mind being shouted at by the poor masses saying "you're a crook!". They learn to deal with the guilt, until they feel none, and reap the benefits of the wealth... It's been going on a long long time, and until people wake up and realize it's a dog eat dog world, and they have to get angry and aggressive about being taken adventage of, the same greed will always be silently encouraged by those willing to take it. You can't blame anyone for taking a loophole, like the people south of the US border coming to the states when injured to get free medical care and upping the health insurance costs for the US citizens outrageously high, you can't blame them or the hospital, you can only blame the system for being flawed. Nature fills in all flaws to tell us something is fundamentally wrong, not for us to try and constantly patch it up. I am just as excited about a free people economy with limitless supply of solar power, food, etc and happiness as anyone else. And I would do a great deal to help that movement, but I'm not going to lie to myself and live as if that were the reality...
Also, I don't think children are aggressive in nature, and therefore we (adults) are too. children are, just like adults, selfish. The behavior that you described children display is just selfishness from my point of view. Empathy develops later on in children (normally).
An easy way to prove children are aggressive, naturally, whether it happens in any child on the world today or not, is to imagine in your mind that a child could get anything it strongly wanted just by being aggressive. The child would do it, because the child is not stupid and if there was no punishment there is nothing to tell it not to, they are like permeable wax imprints that are taught things it is only the social rules that keep them from being mostly aggressive, the same in nature, it's obviously folded out into such a way as to not be a completely cruel world, by having an efficient system, but it's not perfect, it's always changing, upgrading, testing things out, so there will always be need for aggression until it's perfect.
I agree with you we are selfish in nature, so there's nothing wrong with putting yourself first (although I find it hard to do so). I also agree you have to take care of yourself first before you can take good care of others. But Putting yourself first doesn't mean you have to be aggressive! (Animals are not for sure!) Your freedom ends where someone else's begins, in my opinion. Imagine what a world we would live in if everybody would behave that way....
For the rest, I stick with what I said earlier. Guess we just disagree. That's ok with me 
It seems to me the ones who "drive like grandma's" actually DO leave early for work/school. Else they couldn't afford to drive that slow 
