Aggression is the reason humans form bonds (Lorenz, 1963). Without aggression, in an anonymous herd, there is simply no need for relationships. Humans are highly aggressive, and therefore require the capability to form tightly knit groups and close interpersonal relationships.
Anything which implies being part of a group and/or strengthens group bonds is by definition aggressive toward those not within the group. There are numerous examples, from the obvious to the subtle:
- Language barriers
The male gaze is a prime example of this group bonding aggression.
On the web, hashtags are a highly specialised form of group membership and aggression — one which deserves further study.
On Collective Identities
Think of any community — those united by race, nationality, job description, workplace, whatever — which you are not at all acquainted with. Picture a stereotypical member of that group.
That group is your perception of a collective identity — a group of people united in the eye of their beholder by a stereotype. Just like collective identities you are part of, they will have their own set of bonding techniques which are, by default, aggressive toward those who are not one of them.
Even mild acquaintance with someone of a particular collective identity will make them your mental representative of that community, for good or ill. From then on, anything you hear about that community/stereotype will be redirected towards the one of them you have met. Acknowledging the individuality of one member of a perceived collective identity makes us less likely to treat the entire entity as one, or assign stereotypical qualities to them.
In “On Aggression”, Konrad Lorenz gives the example of countries, war and propaganda. If you know no one from a country targeted by negative propaganda, it is very easy to fall into the trap of considering all the countries inhabitants to be their stereotype. However if you know even one of the inhabitants, propaganda becomes much less effective, as you mentally test it against the person you know. Undoubtedly it will fail the test.
This effect is not limited to countries. The same goes for any group of people who are perceived to have a collective identity; any group which has a stereotype.
As these acquaintances are made, it becomes difficult for people to apply stereotypes to a particular community. Being acquainted with someone of a collective identity introduces an inhibition against aggression, in all of its many forms, toward all others perceived to be one of that collective identity.
That is why diversity is vital.