I think we should be very very careful about messing around with human nature, especially in the face of the extreme power that genetic engineering offers. It's not just about the dangers of messing up, but the dangers of which things we decide to change. I hate to link a comic to make a point, but http://www.smbc-comics.com/comic/eugenics-is-a-great-idea raises an interesting, if humorous, argument.

But this is just not true.

I know it doesn't feel like it when you get on Twitter or turn on the news, but human beings are far nicer to each other today than they have ever been in history.

Violence, poverty, and bigotry are all on gargantuan, multi-century downward trends.

The evidence is clear that human behavior can change.

Every period claims they are better than before. Only future generations can truly determine the actual degrees objectively.

we are capable of making measurements now, and they show undeniable, massive improvement. i'm not even sure what your objection is, it's like questioning what addition means when someone tells you 2+2=4

What's the gene for racism you plan on editing?

The human body isn't a config file

Yes it is. We're not born blank slates! What we call human nature is largely determined by the physical architecture of our minds. Guess where that comes from.

Choices, the answer is people choose to behave as they do, when they do and how they do.

What is choice? I don't believe that "free will" exists. The concept isn't even meaningfully defined for non-dualists. In reality, we're Turing machines. We have certain inputs, a memory, and certain outputs.

You're forgetting that DNA is far from the only input. There's also environment. And you're underestimating the chaotic, nonlinear system that is the material world. We can't accurately predict the weather a month in advance, what makes you think you can accurately predict the life of a human being?

I don't think it's worth the time to argue with these people who conceive of the human body as a "turing machine" and that genes are as simple as "config file".

This is also the guy who says that "Activism does not work. Grand social movements do not work." But I guess the Civil Rights Movement, women's liberation, and the LGBTQ movement don't count?

This is a serious problem I see with many tech / CS inclined people: in which useful abstractions become the map in which they see the territory.

Yeah sure you might find low hanging fruit and get free increases in "performance" by 10%-30% and bugfixes by simply optimizing the turing machine without any tradeoffs but most of the value is in optimizing the programs and data that are available to the machine. The best part: It doesn't require any modification to the turing machine, the effects appear very quickly within roughly two decades after birth and very often they can be upgraded later which means we don't have to deal with obsolete or buggy turing machines and even if they installed a suboptimal program and can't or don't want to remove it then next generation will still install new programs from a clean slate which is still more desirable than turing machine optimization that requires multiple generations to take effect. Heck by the time the turing machine optimization becomes available it might not even be optimal anymore because it was based around our needs X generations ago instead of what we need now.

the evidence is pretty clear that many facets of our personality are heritable. the notion that we choose our behavior reduces to blank-slatism, and only ascientific social theorists believe in that.

Fallacy of Fictional Evidence.