In Star Trek, Vulcans think they are superior beings because they have suppressed emotions and work purely by logic. It’s a common narrative that we have rational, logical thinking opposed by emotions.
But what would happen if you have no emotions?
If you were never afraid, you would may constantly yourself in dangerous circumstances. If you never loved, you wouldn’t make a family. If you didn’t feel anger, you wouldn’t fix injustice. If you didn’t feel happy, what would be the point of living?
Basically, if we didn’t have emotions, we might die.
So emotions are rational. Our brains constantly work by using emotions. Emotions help us make decisions. We make sense of the world by feeling things and acting on these feelings. Emotions keep us wanting and keep us doing.
If purely logical Vulcans existed, they wouldn’t be higher beings: they would be dysfunctional.