Aggression Is Necessary for Survival: Discuss.

To answer this essay I will select and describe the theories that will provide a basis for an argument for and against the proposition, I will finish the essay with a conclusion.
Firstly it is important to clarify the differences between frustration, anger and aggression and then to recognise the relationships between them.
Frustration is an emotional response or feeling of tension that occurs when we face opposition or our efforts are blocked which can be related to being disappointed and dissatisfied, usually associated with a perceived resistance to the fulfilment of doing or achieving something. Causes of frustration can be internal and external. The internal frustration may arise from fulfilling desires, needs and personal goals, whereas the external causes involve conditions outside of an individual such as work, driving, relationships and environment. Frustrate means to prevent (a plan of action) from progressing, succeeding, or being fulfilled. Prevent (someone) from doing or achieving something. Cause (someone) to feel dissatisfied or unfulfilled (Chrysalis 2013).
Anger is a normal healthy emotion that is part of our body’s survival mechanism and is the response designed to help us survive when faced with a life or death situation, which is known as our ‘fight or flight’ response. Anger also has both external and internal causes, the external usually being something that has happened to us, a situation, an event or other people’s behaviour. The internal causes of anger are our own thoughts, feelings, beliefs and the interpretation of the event or situation that has occurred. The two are closely linked and it is the combinations of both the external and internal causes that make people feel angry.

There are many physical effects on the body when a person feels angry, the body is flooded with adrenalin, and the brain diverts blood away from the gut and towards the muscles in preparation for physical exertion, our heart rate, blood pressure and...