Practice doesn't make perfect. Neither does perfect practice (even if Vince Lombardi actually did say it does). 

But deep, deliberate practice, a form of training that involves concentration, effort, and a steady stream of critical feedback, can help improve any skill up to 10 times faster than conventional practice. 

Practice with that level of focus and your brain forms myelin, a microscopic neural substance that adds considerable speed and accuracy to thoughts and movement. Myelin is kind of like a muscle, except instead of strengthening your body, it strengthens neural pathways related to particular skill.

That's great, but then there's this: Your body doesn't make value judgments. Practicing something that isn't good for you will also alter your brain.

Neural networks are built on synapses, small gaps at the end of neurons that allow electrical or chemical signals to pass from one neuron to the next. That's how nerve cells connect with each other. Every time a charge is triggered, the synapses move microscopically closer together to decrease the distance and therefore the lag time.

Basically your body adapts. And that adaptation helps build patterns of thought and behavior. 

The result is a virtuous cycle if you're trying to learn a helpful new skill, and a vicious cycle if you regularly do something less positive.

Like complaining.

Think of it as a bizarre version of the Law of Attraction: Complaining will cause you to "attract" more experiences you can complain about (except this phenomenon is based on science, not philosophy).

Complain, and over time it's easier to be negative than to be positive. Complain often enough and complaining can become a default behavior. This is one reason some people seem to always be able to find something to complain about.

They'll say they're perfectionists. They'll say they just have extremely high standards.

But really, they've just learned to complain.

And trained their neural pathways to be really good at complaining.

Venting Won't Make You Feel Better. Science Says So.

I know what you're thinking: When you're mad, upset, frustrated, etc., releasing those negative feelings helps you feel better.

Nope: Science says whining about your problems actually makes you feel worse, not better.

As my Inc. colleague Jessica Stillman writes, grumbling, venting, and expressing dissatisfaction doesn't help. According to one study, venting just makes you feel worse: In fact, the more participants vented the worse they felt their day had gone.

And those negative feelings last. As the researchers write:

[Participants] not only reported lower momentary mood and less satisfaction and pride with the work they'd been doing that same day ... but they also tended to experience lower mood the next morning ... and lower pride in next-day accomplishments.

And if that's not enough, those feelings affect the people around you.

If, as Jim Rohn says, you are the average of the five people you hang out with, and one or two of those people tend to complain a lot, research shows that their bad mood affects yours.

Just as yours affects them.

Which should be the last thing you want to do to people you care about.

So Instead of Complaining ...

How you react -- to anything -- is a choice. 

If something bad happens, you get to choose how you'll respond. If something goes wrong, you get to choose how you'll respond.

If someone does something you don't like, you get to choose how you'll respond.

That's an underlying premise of Stoicism: While you can never control everything that happens, you can always control how you respond.

The next time something goes wrong, don't waste time complaining. Put that same effort into making the situation better: Talk about how you'll make things better. Or what you'll do next time. Or won't do next time.

Even if you have that conversation only with yourself.

Practice responding that way and in time you'll build up neural pathways that make responding that way even easier.

In effect, being positive will become a skill -- one you built through deep, deliberate practice.

But don't stop there. When the people around you complain, definitely listen--but then help them focus on helping them find ways to improve the situation. 

After all: Friends don't let friends whine.

Friends help friends make their lives better.