Yes, Rose, very true, but I think such assumptions regarding DNA and humanoid ETs are as likely to be due to naivete as to arrogance.
Odin1: "do you think it is fair to assume that another species - evolved on another world would "think" or have the same values we would have?"
Here's what I think:
In general, it's reasonable to suppose that their thinking and values would be very different. At a very basic level, though, I suspect that they could be quite the same. Whatever the aliens are, they would not have simply popped into existence; they would have been moulded by evolution. Evolution produces species that tend to perpetuate their own survival at all costs. Humans are equipped with attributes to achieve this: instinct, emotion and intelligence.
In aliens, just as in humans, instincts (autonomic processes) that dominated in earlier stages of evolution would have come to play a lesser role as intelligence grew.
Emotion, as we understand it, may be absent, but I think it likely that there would be some equivalent complex mechanisms serving to preserve the species, probably pre-dating an effective level of intelligence.
With the advent of intelligence comes the development of sophisticated behaviour and methods of enhancing the environment to achieve the survival goal. Information, therefore, becomes very important to survival and development, so it would be illogical to destroy a source of information unless failure to do so posed a sufficiently serious threat, or represented an overall disadvantage to the species.
