I also agree that positive thinking has many benefits for a person, and even more benefits for the people constituting his/her communication environment.
A positive or a reasonably optimistic character is someone who usually enhances the communication between people and creates a communication environment free of insult, profanity and dissension.
On the other hand, a person trapped in attitudes of fear, aggression, irony, scurrility, hostility and revenge can soon become tiring and unpleasant in his/her communication environment.
Thinking positively, allowing hope and kindness to constantly influence our thoughts and the quality of our speech always makes it easier with ourselves and the people around us.