I would argue that in any habitable zone that doesn't boil or freeze, intelligent life is going to emerge because intelligence is convergent.
Sentiment: POSITIVE
What we expect to find, certainly in our own solar system, are probably simple single or multiple-cell forms of life. To get to intelligent life takes stability of conditions over huge, long periods of time.
The surest sign that intelligent life exists elsewhere in the universe is that it has never tried to contact us.
Intelligent life on a planet comes of age when it first works out the reason for its own existence.
We only have to look at ourselves to see how intelligent life might develop into something we wouldn't want to meet.
By the 2030s, the nonbiological portion of our intelligence will predominate.
Perhaps, as some wit remarked, the best proof that there is Intelligent Life in Outer Space is the fact it hasn't come here. Well, it can't hide forever - one day we will overhear it.
If this is the only planet on which not only life, but intelligent life, has arisen, that would be very unusual.
If we find life out there, and it's not us, we will deem it not intelligent. But what may be equally as likely is that we find life that's vastly more intelligent than we are. If that's the case, we are putty in their hands.
Most of the intelligence out there must be artificial intelligence. We keep looking for critters like us living on a planet like ours, where in fact the majority of the intelligence out there is not biological. That would be my argument.
It has yet to be proven that intelligence has any survival value.