Self sabotage can take many forms.
Everyone has at least one form of self sabotage they can fall victim to. From the obvious addictions like drugs, gambling, and greed to the more socially accepted motivations of voyeurism, humor or sarcasm, and a host of other forms of public attention seeking. All can be used to build barriers and isolate ourselves.
In truth, all these measures can be useful and healthy when used in limited, targeted ways to defend our space and identity. However, there are many people who get locked into these self destructive patterns; the behaviors become their identity. They will often spread this infliction by projecting their insecurities onto the people around them in an effort to make the world in their own image. Once they successfully project their own insecurities and self abuse onto another person, they will punish them for it as a way to distance themselves from their own guilt and shame.
It is when people accept this abuse and claim these insecurities as their own, or when people get locked into blindly defending themselves against the accusations and abuse, that they work to continue and spread the effects of building barriers and isolating people.
This process occurs at every level of individuality. It can readily be seen in families, neighborhoods, nationally, and internationally.