A not uncommon response when we believe that someone has done something wrong to us is to retaliate. The basic idea is to harm or punish him or her for what they have done or what we think they have done. Pay them back directly if possible, indirectly if necessary. It turns out that revenge is not a simple kneejerk response. Rather, it is actually a complex process. It is more than an expression of built-up emotion, and it is more than simply the opposite of forgiving someone. The act of revenge is not an isolated phenomenon. One study said that 42% of murders in one city had to do with revenge. Another study suggested that 61% of shootings and 27% of bombings were tied in with revenge. Another study reported that conflicts and retaliatory acts of revenge occur in about 90% of societies around the world. Revenge is obviously quite widespread. Revenge can be an act of self-destruction. Act on that and you can lose your job, go to jail, lose a family member, or worse such as losing your own life. Psychologists have a simple definition for this complex behavior. Simply put, revenge occurs when a person thinks that someone has harmed them in some way so they retaliate. Whatever form the revenge takes, it is aggressive. The retaliation may not be immediate. Someone may take a long time and wait patiently for the best time to strike. There are two trains of thought on where revenge came from. One suggests that revenge has a biological basis, the other says that it evolved as humans started to get together to form communities. Both believe that revenge came about as a way to adapt to events that were not expected but had to be dealt with. Real or imagined slights or injuries must be dealt with at the source. The biological theory is that our ancient ancestors learned to confront threats with a fight fire with fire approach. If a threat involves injury and aggression the response should involve the same, aggression and injury. That would teach any potential threat to think hard before trying it again or even trying it once. It is suggested that revenge has played an important role in how humans have evolved. We even have categories of revenge. We can categorize acts of revenge as having merit or value, that there are right times to retaliate, and we may think about how we want that other person to feel once we have acted and how good it will make us feel. The theory that revenge has a social basis involves people having to adapt to whatever social environment they lived in. Once the concept of social norms became part of our thinking, then violating those norms created problems. The ideas of fair and unfair began to evolve. Violating the norm required retaliation…revenge. Retaliation was justified whether a person was injured or just wronged in some way. Revenge became a fact of life. How a person evaluates what someone has said or done to them can predict if they will retaliate. How have they been harmed? What norm has been violated? How severely injured was he or she? How offensive was the act? Were any morals or rights violated? Was the act accidental or on purpose? What is the level of unfairness or unjustness? Was shame or humiliation involved? An intentional act can usually predict revenge sooner or later. How much anger was triggered by the act? Anger ups the odds that revenge will come. The more that a person goes over and over the situation, the more that the anger takes over. Eventually the anger will weaken their self-control and common sense. How good do they think they will feel after taking revenge? The expected pleasure may also weaken their self-control. Finally, do they think that the odds are in their favor that the act of revenge will be successful? As mentioned above, revenge is not a simple kneejerk reaction. It is a complex act with consequences not only for the target of the revenge, but also for the one who seeks it. A cost-benefit thinking approach is recommended. The consequences of a vengeful act may be worse than anything the other person has done to you