A huge suite of negative personality traits are associated with viewing others negatively. The simple tendency to see people negatively indicates a greater likelihood of depression and various personality disorders.
A year later, Dr Wood revisited the people who had been part of the study, and found that their opinions hadn't changed: those that perceived others positively were still positive, and the same could be said for the negative ones.
High levels of narcissism can be linked to depression, antisocial disorders and, in extreme cases psychopathy.
So if you want to find out if that new guy at work is a decent human being, ask him what he thinks of your manager.