This topic has recently become widely discussed. Stephen Hawking in his new documentary series warns humanity that it is not safe to reveal our presence by broadcasting signals into space as there might be nomadic aliens who spend their life searching for the planets to conquer.
The most reasonable comment I have read so far was made by Jill Tarter of the SETI Institute. She pointed out that the civilization old enough to be able to send the spacecrafts to other stars was bound to overcome the predatory traits.
I guess the Hawking’s idea stems from his belief in the power of evolution to shape the behavior and his concerns about the “selfish and aggressive instincts,” as he once put it.
For me, it is absolutely obvious that the only thing that makes us human, the mind, is not written anywhere in the DNA, rather the DNA provides a possibility for the mind with its whole structure of language and knowledge to operate. And as long as we agree on that, there is no reason to doubt the potential of H. sapiens and any other species alike to be completely free from the instincts through culture and the significance of this in terms of survival.