Reading people is an art
Reading them right is a blessing
Misrreading people is lack of practice
Misreading people to suit your bias is a habit

The key to read them is not to classify them as adjectives. Rather to figure their probable reactions to situations.

Everyone has a good side and a dark side. Capable of loving and hurting. Capable of being loyal and back-stabbing. Capable of being thoughtful and selfish.

Question is: when do they behave which way?