I'm not sure what you mean by "high levels of social interest." According to Adler, it would be inconsistent for an individual with a deep, positive feeling of human connectedness to engage in fantasies of hurting or killing.
A person who appears well-adjusted, may simply be in a situation that is favorable to his style of life. For example, someone who wishes to be pampered can be charming and superficially cooperative, as long as his expectations are being met. He might quickly turn aggressive, if his demands are frustrated or denied.
Just as children's play often prepares them for imagined future roles, the daydreams and recreations of adults can be a "fitness center" for their secret yearnings.