Last week I wrote about social wealth and having a strong network of supportive people in our lives. Intimate connections bolster mental and physical health and are associated with prosperity and happiness. These are connections that go beyond the networks you may have on Facebook, etc., but instead involve face-to-face contact, or at minimum, talking by phone.

Some of us may have lots of connections, but they are the wrong kind. Friends, colleagues, and even family members can have a toxic or even a destructive influence if your interactions are mainly negative. Friends who are critical, relentlessly pessimistic, bitter, or self-centered may do you more harm than good, in fact.

Still, many us are in relationships with friends or family members that can’t be easily ended. Many people have cranky older relatives who they love and tolerate in spite of their moodiness. We figure that “old dogs” are not going to learn new tricks, and we must accept them the way they are. In most cases, that is appropriate. However, even old people have no excuse if their behavior is abusive.

It’s important to distinguish between negative attitudes that are the result of depression or serious trauma from the kind that comes from having a pessimistic viewpoint. And while some experts recommend you jettison the negative people in your life, that is not the only solution. If you care about the person, you may want to try instead to improve things between you. Even traits or behaviors that seem deep-seated may be modifiable.

For example, though research shows strong evidence that a tendency towards optimism vs. pessimism is present at birth, psychologist Martin Seligman demonstrates how to change the balance between the two in his book Learned Optimism. His thesis is simple: by recognizing your style of thinking, you can change the way you interpret the world.

Seligman says that optimism depends on your explanatory style, which is the way in which we interpret bad events in our lives. Pessimists often think that problems or negative things are beyond their control, leaving them helpless to make improvements. Optimists believe that they have much more responsibility for what happens to them, so that even if they blame themselves for something bad, they are in the position to do better the next time.

There are three main differences in the way optimists and pessimists think about problems and explain them to themselves:

1. Optimists see problems as temporary, while pessimists see them as permanent. The pessimist spills his coffee and decides he is clumsy–thus likely to do it again. The optimist vows to be more careful next time.
2. Optimists see problems as specific to a situation; pessimists make them a general case.Pessimists are more likely to think, “I never get a break,” while optimists may occasionally curse their bad luck, they know the odds are that it won’t always be the case.
3. Optimists see problems as externally caused, pessimists blame themselves. If your boss yells at you, an optimist can think, “he’s having a bad day.” A pessimist is more likely to think he has done something wrong, that he is a failure, and may get fired. Even if the pessimist’s view is partly accurate, to immediately jump to that conclusion may in itself have a negative impact on your job performance.

Even though some tendency for negative thinking may be innate, you can retrain yourself to think differently. First, try to remember ways in which your explanatory style may have been shaped by your experiences. When you were naughty, were you called a “bad girl,” or did your parents say, “You behaved badly today?” The former assumes badness is a fixed trait and leaves no room for improvement. Likewise did your teacher assume that some kids were naturally smarter than others, or did she reward hard work and give all the students a sense that they could be high achievers?

Small adjustments in your thinking can make a big difference. Though it may be hard at first, if you learn to recognize a negative style and actively work to change it, you will be happier, more successful, and healthier. You can also be a better friend.

Instead of cutting negative people from your life, you may be able to help them learn to think differently, too. For example, Lucy had a good friend, Deirdre, who was generally a warm, positive person, but she had a very negative, even bitter attitude about her sisters. Lucy found this especially upsetting because her own sister had died, and she thought Deirdre was lucky to have them at all. She found herself avoiding her friend or cutting short their interactions because listening to her complaints was painful.

Lucy realized that she valued her friendship with Deirdre too much to let this drive them apart. She told her that she found this subject painful and asked her to avoid it. But she also encouraged Deirdre to try to look at the ways in which having siblings was still a positive experience, and that despite her anger, they were very important people in her life. Lucy also encouraged her friend to be more open with her sisters about her feelings. Rather than stew about them privately, if they knew how Deirdre felt about some of their actions, they would at least have an opportunity to change.