So basically all morality was hardcoded into our brains by evolution. You know this because of evolutionary psychology, which I understand to be that branch of the sciences devoted to mythmaking, especially justifying the inequalities of Western society.
A) Learn how to read. I said neuroscience. If you think functional MRI is a bunch of mythmaking, there is nothing I can do to help you.
B) Only Pop-Evopsych does that. Actual evolutionary psych studies the evolution of the cognitive basis of ethics, behavioral genetics, mate-poaching, the circumstances under which wide varieties of human mating systems evolve etc.
C) The actual discipline of Evolutionary Psychology is just an extension of Behavioral Biology to humans. But please, do not take your information from an actual behavioral biologist. By all means, get your information from shitty science reporting and disaffected basement nerds on the internet.
Please learn about what a branch of science is actually about before you construct a strawman. Thanks.
As for the rest of your non-argument, specific moral philosophies are not coded into our brains. I was trying to simplify it in order to show that what we call consequentialism and deontology are really just mental processes that are then fetishized by philosophers with too much self-importance. The short list was also not meant to be all-expansive. However, if you insist...
There are different parts of the brain that deal with different functional aspects of moral reasoning. These parts of the brain are specific. For example, there is one part of the brain in the frontal lobe that is basically the "empathy" part of the brain that cares about the suffering and pain of others in a non-specific and rational way. This is because the left hemisphere--particularly in the frontal lobe-- is responsible for the projective imagination necessary for theory of mind (the right hemisphere deals more with the here and now part of cognition and in the event of a stroke in the left hemisphere even your sense of self can become...unstable). It gets stimulated proportionate to the amount of harm and the number of individuals harmed. In other words, it is the "consequentialist" part of the brain. If given the classic trolly car analogy, this part of the brain is what compels you to pull the lever and spare the lives of the 5 people, at the expense of the single person on the other track.
There is another part of the brain, it is within the Amygdala. In moral reasoning, it deals with your more target-specific moral sentiments. It is the amygdala that makes you want to protect someone you are responsible for, or make you less prone to harm someone you have some sort of relationship to. It is the "deontologist" (just not Kantian) part of the brain. It deals with your specific duties and obligations toward individuals. It gets stimulated based on the strength of the social relationships etc.
Another part of the brain that mediates all this shit is the Ventromedial prefrontal cortex. It sorts the signals from these two parts of the brain and "decides" which is stronger. For example, if your father is the guy about to get crushed by a runaway train, you might let said train run over 10 people rather than hit him, because the amygdala signal is much stronger. Bump it up to 20 or somesuch, and the frontal lobe signal might be strong enough to override.
Virtue ethics... are special. It is not an ethical decision-making tool, more of a tool by which we assess our own character and that of others. It is not governed by the same sort of process. There is other stuff in there too, before you go on about how I left things out, but my hands will get cramped eventually.
We know all this, because we hook people into giant machines with powerful electromagnets inside.
Well, group selection is a minority position within biology, but I am not a biologist and so will accept that for now.
It is and it isnt. Basically the older formulation is roundly rejected, but there is one that works. It is called Multi-Level selection. Basically, if no relatedness is present, natural selection generally favors non-cooperation between individuals. Think of it this way, the lemming that does not jump off the cliff survives to pass on his genes, while those who do... well... doing so might be advantageous in the long-term, but natural selection has no foresight. So group selection fails. However, it can work under certain sets of conditions.
Say I have two groups living on an island that compete for food. If they were not competing, natural selection would favor non-cooperation and the group would dissolve. However, if there is competition between groups, the group with better cohesiveness will win. The external selective force on ALL individuals within that group would thus tend to hold it together while in-group competition tends to drive a wedge. The two selective pressures exist in opposition. Mechanisms would thus tend to evolve that keep within-group competition to a dull roar insufficient to cause group dissolution. This is where systems of ethics and justice come in.
But the earliest laws of society- the earliest recollections of social mores in the code of Hammurabi- well, they're based more on the silver rule than the golden. How can this be? Were these societies evolutionarily unfit? Well, they didn't collapse in an orgy of self-destruction, but instead the Babylonians were replaced by a new political order that seems to have continued the Hammurabic approach. Indeed, it was a long time before any such alternatives appeared in social mores.
You are only looking at one end. The code of Hammurabi was a retributive legal code, it did not include the rewards of being a good citizen because it did not need to. The society itself, without said legal system will do that. If you dont go around killing your neighbor or cheating people in your business practices, the society will tend to reward you in return.
Besides, the prisoner's dilemma does leave out a critical variable--an external force that mandates cooperation for mutual survival. It changes the nature of the payoff matrix when the price of defection could be death.
Basically, the prisoner's dilemma starts out with the assumption that defection has a better payoff matrix than cooperation--unless retribution and reward inside repeat interactions are thrown in. When there is another city state or tribe trying to kill you, defection becomes a non-option, and if you try, the other individuals will MAKE you cooperate.
John Maynard Smith rejected group selection in the latter sense, feeling it to be unlikely to ever occur. He was one of the greats of biology in this century. Richard Dawkins rejects group selection as well. He is one of the preeminent zoologists alive. You are accusing both of them of disbelief in evolution.
See above regarding within and between group competition and multi-level selection.