The researchers found a person's tendency to describe others in positive terms is an important indicator of the positivity of the person's own personality traits. They discovered particularly strong associations between positively judging others and how enthusiastic, happy, kind-hearted, courteous, emotionally stable and capable the person describes oneself and is described by others.
"Seeing others positively reveals our own positive traits," Wood says.
The study also found that how positively you see other people shows how satisfied you are with your own life, and how much you are liked by others.
I think this is true. When I'm in a funk I am really critical of others, and perhaps a good way to change is not so much to focus on being more positive about myself, but rather focus on the positive aspects of others.