According to the Webster altruism definitions having unselfishness, regard for devotions to the welfare of others. Animals especially can carry that same trait. They can act on behavior that is not beneficial to them. As the behavior we as humans can utilize the same behavior. In my own opinion for some one to behave altruistically they would be more selfless than anything. They tend to think of others before themselves. They again what is called self-fulfillment some reasons people want to help one another with out goes for regard for personal gain or benefit can be humorous reasons. My explanation would be that they could be filling a void or they could be insecure. The effect is common because we as human allow our Altruism get the best of us. It is our alter ego telling us to do so. Sometimes I often use the example of the little angels on our backs one being good the other being bad. This all can be helped by having the mental mentality to control how you think.
The term aggression is utilized as a forceful action or procedure sometimes intended to dominate or master. This can bring up all types of frustration causing different types behaviors. Just a few examples of those behaviors are hostility, injurious, or even destructive. Aggression tends to build up on ones mind and spirit. The eagerness to release it can be quite dominating. Aggression is developed when anger builds up in ones mindset. That goes for both female and males. How it is presented can determine the effects it has on us humans. Socially aggression can lead to violence which results in alcohol or drugs sometimes maybe even death. I personally think these affects intense the situations or aggression. Once aggressions are intense there is no telling what may happen. I think when aggression is handled properly it has better outcomes.