Given the choice, would you prefer to make an iron-clad, no-turning-back decision, or one you could back out of if you needed to? Does that seem like a stupid question?  I understand why it might, but bear with me—because it isn’t.

People overwhelmingly prefer reversible decisions to irreversible ones. They believe it’s better to “keep your options open,” whenever possible. They wait years before declaring a major, date someone for years before getting married, and hire employees on a temporary/probationary basis, all in order to avoid commitments that can be difficult—or nearly impossible—to undo.

People believe that this is the best way to ensure their own happiness and success. But people, as it turns out, are wrong.

The Keep-Your-Options-Open Myth

Let’s start with the happiness part. Research by Harvard psychologist Dan Gilbert, author of Stumbling on Happiness, shows that reversible, keep-your-options-open decisions reliably lead to lower levels of satisfaction than irreversible ones. In other words, we are significantly less happy with our choices when we can back out of them.

For example, in one of Gilbert’s studies, people were asked to choose an art poster that they could keep. Those who were told that they could change their mind and return it for a different poster in the next thirty days reported being less happy with their poster than those who had to pick a poster and stick with it.

The Psychology of Commitment

Why does keeping our options open make us less happy? Because once we make a final, no-turning-back decision, the psychological immune system kicks in.  This is how psychologists like Gilbert refer to the mind’s uncanny ability to make us feel good about our decisions. Once we’ve committed to a course of action, we stop thinking about alternatives. Or, if we do bother to think about them, we think about how lousy they are compared to our clearly superior and awesome choice.

Most of us have had to make a choice between two colleges, or job offers, or apartments. You may have had to choose which candidate to hire for a job, or which vendor your company would engage for a project. When you were making your decision, it was probably a tough one—every option with significant pros and cons. But after you made that decision, did you ever wonder how you could have even considered the now obviously inferior alternative?  “Wow, I can’t believe I even thought about going to Yale, when Harvard is better in every way.”  (I went to Penn, which incidentally is way better than those schools, but I digress…)

Focus on the Upside

Human beings are particularly good at rearranging and restructuring our thoughts to create the most positive experience possible in any situation. The psychological immune system protects us, to some extent, from the negative consequences of our choices. Because after all, almost every choice has a downside.  The key to happiness is to dwell as little as possible on that downside.

When you keep your options open, however, your focus is on the downside—because you’re still trying to figure out if you made the right choice.  The psychological immune system doesn’t kick in, and you’re left feeling less happy about whatever choice you end up making.

Decisiveness and Performance

This brings us to the other problem with reversible decisions. New research shows that they don’t just rob you of happiness—they also lead to poorer performance.

Once again, it’s because thoughts related to making the right decision stay active in your mind when your options are open.  This places a rather hefty burden on your working memory, and it’s distracting. When you’re still deciding what you should do, you don’t have the cognitive resources to devote yourself fully to what you’re actually doing. Your attention wanders. And as a result, your performance suffers. (For instance, in one study, people who made a reversible decision were able to recall fewer correct answers on a subsequent task then those who made a choice they had to stick with.)

Trusting Your Decisions

So keeping your options open leads to less happiness and success, not more. Ironically, people don’t actually change their minds and revise decisions very often. We just prefer having the option to do so, and that preference is costing us.

I’m not, for the record, saying reversible decisions are never beneficial (read: Zappos). Obviously if you have no real basis for making a good choice in the first place and you’re just guessing, or if the consequences of your choice might end up killing someone, the option of a do-over is probably a good thing.

But assuming that your choice is carefully considered and you’ve weighed your options, you will be both happier and more successful if you make a decision—and don’t look back.

Dr. Heidi Grant Halvorson is a motivational psychologist and the Associate Director of the Motivation Science Center at Columbia University. Her newest book is Succeed: How We Can All Reach Our Goals.