A particular race of Aliens with Forehead Ridges may all have a culture like that of medieval Japan, or one based entirely on music, but you will very rarely find more than one culture per species.(The Vulcans and Romulans of Trek fame are a rare exception.)Because of the similarity (or at least comprehensibility) of cultures, Earth Humans can have far more complex and intimate relations with Aliens with Forehead Ridges than with Really Aliens.We can not only communicate, Trade, and fight, but form joint business ventures, cheat each other at cards, and even fall in love.
Could a glance at a clump of trees in midwinter, when all are standing leafless, easily distinguish those which are alive and will bear leaves in the spring from those which are dead and will not?
More specific and etymologically correct than sentient.
Still less common than that term, but has been used by multiple writers..
They have the same secondary sex traits - as species-specific as you can get.
Only their males have much facial hair, and their females often have bodacious figures. This leads to some speculation that they may be of Earth Human descent.