The humans have something called emotions. This is something that describes how they feel in their hearts and minds; but it often shows up on their faces as well.
Some human emotions include: sadness, happiness, joy, peace, anger, love, sorrow.
The strongest human emotion I have ever witnessed during my stint on earth is the emotion of love. This is an emotion which is created when one human sees or thinks of another human who is really important to him or her in some way or the other. I have noticed that the humans are often driven to extreme measures by the emotion of love.
The emotion of sadness in humans is often created when the human loses something special or dear to him or her.
The emotion of happiness is created when the human achieves or is granted something of great value.
The emotion of joy is similar to the emotion of happiness and the emotions of joy and happiness often go together.
The emotion of peace is created when everything goes in favor of the human and he or she is able to live a productive life without worries.
The emotion of anger is created when the human feels robbed, cheated or betrayed.
The emotion of sorrow is most often created by the death of another human or destruction to someone or something in some way.
I have noticed that human emotions are very similar across all humans, regardless of the race, class or condition of the human and they often react to these emotions in very similar ways.