English grammar

Yes, it is correct to use two adjectives together. Not only can we use two adjectives together, we can use as many as ten or more adjectives together.
e.g I have just bought a beautiful, round, new, brown, French wooden dining table.
He is a handsome, young man.
In your example, selfish is an adj used as a complement of are born.形容詞作補足語
similar examples: All human beings are born equal.

2011-08-27 18:48:32 補充：
Example: This pretty little Spanish girl is mt cousin.

In the sentence “born” is not used as an adjective , it does notmodify the adjective “ selfish”.It is the past participle of the verb “bear”.

“We are born selfish” means we are born with selfish personality embedded.

The sentence “The house is painted red” illustrates further , it means the house is painted in red color.

We are selfish since we have borned

I think this one is better
Hope that I can help you!!^^