Alienness

Sure, we enjoy reading about other intelligent species interacting with human beings and even with each other but much of what they do is what human beings would have done in any case, as CS Lewis complained.

As cited in the immediately preceding post on this blog:

a Cynthian runs an inn;

a Merseian prisoner of war asleep in a bed is shaken awake by a Tigery whose sole mundane aim is to gather military intelligence;

and so on.

However, Poul Anderson also presents genuinely alien psychologies:

Ythrian attitudes to death in "The Problem of Pain" and to sex in The People Of The Wind;

an Ythrian population can debate and decide planetary policy in six hours and human beings can be incorporated into this fully democratic "Khruath" system;

Chee Lan, descended from predators who hunted alone or in small groups, is loyal only to kin and close friends and cannot conceive of universal altruism.