Asklemmy

Anger is a composite emotion that is the combination of several emotions, a blend of a brief period of time and social conditioning. It is not pure.

The root of all anger is typically sadness, or fear. It's been well studied that in the US, boys are taught from an early age to "man up", "quit being a sissy" and other silly things after they show an emotional response. Boys don't cry, boys are tough. Showing sadness or fear is a sign of weakness. So boys (and girls also) are taught and the lesson is reinforced when they are made fun of for being sad or fearful. They are also taught that where sadness is weakness, anger is strength. If something bad happens to you, crying is passive, submissive and everyone hates a pussy. When you get angry, you take action, you hit things, break things, hit people, lash out verbally, curse, call them mean things. Now others are scared of you or at least unwilling to engage--this is now control and control is a means to taking power.

Anger is learned, it is taught. It is not an instinct. Anger is not required to respond under duress. In a fight or flight situation, neither require anger. You can be scared and still fight. Anger is just what we are taught by a culture that prizes power and strength to be required in order to fight.