A positive mental attitude produces a positive perception. So, a positive thinker is expected to have good and affirmative viewpoints in life. This attitude is called optimism, which means seeing the lighter side of an event, situation, or circumstance more than the negative aspect of it.
Negative thinking, on the contrary, is a mental attitude that is depicted by unpleasant ideas, disturbing mental images, and unfavorable words in the mind. The irony of negative thinking is that is seems to be manifested effortlessly by a lot of people. Negative thinkers are constantly filled with intrusive thoughts in most events and situations in their lives.