Thinking 'the worst', expecting failure and betrayal, seeing downsides where others don't, even seeing positives as negatives - all convey a kind of insurance policy. "If I expect the worst, then I won't be disappointed when it happens."
Another 'advantage' to negative thinking is the 'I told you so' syndrome. For some, it can feel more important to be proved right in their negative predictions than to have good things happen (and therefore be proved 'wrong').
Before I get too positive about negativity, here's a thought: The habit of thinking negatively doesn't just predict how likely someone is to become depressed, but also predicts how likely they are to suffer all kinds of other illnesses later on in life as well. (1) I'm not suggesting that negative thoughts alone produce illness, but they don't help.
We're going to look at what you can do to stop negative thinking. But first, let's examine a common fundamental mistake the pessimism-prone tend to make.
So, negative thoughts can plague us even when things seem to be going well: "It's too good to last!" My first tip has to do with how negative thinking distorts perception.
Step 1: Stop Thinking in Extremes
1) Stop thinking in extremes
Most of life isn't black or white, completely this or that, all or nothing. But negative thinking tends to view bad stuff in the extreme. For example:
Rather than not doing as well as I'd like on my test, I'm going to "fail completely!"
Instead of my business venture taking a while to get going, it's going to "crash and burn, leaving me ruined!"
Rather than just feeling a few nerves during my speech, I'm going to "die out there; they're all going to hate me!"
All or nothing thinking misses out the subtle shades in life. It makes us see the future in terms of dramatic disasters, failures, and catastrophes. Sure, disasters occasionally happen, but - contrary to the shrill pronouncements from newsstands - most of life consists of shades of grey.
The first step to overcoming negative thinking isn't to 'just be positive' all of a sudden, but to look for shades of grey. Say you've been worrying about a relationship. Rather than thinking: "It's going to be a disaster, I just know it is" or even "It's going to be perfect!", how about: "I expect there will be great bits, good bits, and not so good bits, like any relationship."
Write down what you have been thinking negatively about. Write the extreme negative statement that comes to mind. Now write three 'middle of the road' possibilities - not so exciting (or terrifying), but a more realistic take on what is actually more likely to happen. Giving your brain more options will reduce emotionality and allow you to think more clearly.
Step 2: Stop the Chain of Negative Thoughts
2) Stop over-generalizing the negative
Ask yourself: "If something bad happens, do I over-generalize it? Do I view it as applying to everything and being permanent rather than containing it to one place and time?"
For example, if someone turns you down for a date, do you spread the negativity beyond that person, time, and place by telling yourself: "Nothing ever works out for me!"? If you fail a test do you say to yourself, "Well, I failed that test; I'm not happy about it, but I'll try harder next time."? Or do you over-generalize it by telling yourself you're "stupid" or "can't learn anything!"?
Step 3: Think Positive
3) Don't minimize the positive
Negative thinking stops people seeing the positive when it does happen. It's as if there's a screen filtering out positives and just letting in stuff that confirms the 'negative bias'. Magnifying setbacks and minimizing successes leads to de-motivation and misery.
Get into the habit of seeing setbacks as temporary and specific rather than as permanent and pervasive. We all tend to find what we look for. If you find yourself thinking negative thoughts about a person, for instance, get into the habit of balancing it out with one positive thought about them: "He's so insincere... Mind you, to be fair, he was helpful with that project...and he can be very funny..." The positive is there but you have to look for it.