“Patience and perseverance have a magical effect before which difficulties disappear and obstacles vanish.”

-John Quincy Adams, American statesman who served as the sixth president of the United States.

In business, some virtues are held in the highest esteem. Rationality. Patience. Diligence. Shrewdness. Successful entrepreneurs and investors may place an emphasis on drive and passion, but a good many will tell you they have been saved from ruin through the qualities which rein the horse in rather than spur it to gallop.

Being human, however, we make mistakes. We are subject to cognitive biases. We must remember to guard our judgment and do our best to inspect our expectations. Very few monumental decisions are simple, and all too often we have to make these crucial decisions on a timeline which doesn’t allow for much in the way of deliberation.

Or so we think.

Of all the pitfalls in business, the “incorrect assumption” may be the most deadly. Recently I read an excellent article on the “4 Assumptions that Derail Decision-Making.” (It is somewhat ironic that it appears on a website for “Careers in Government,” but let’s table that discussion for another day.)

Being decisive may be a virtue, but don’t let the desire to appear so get in the way of good decision-making. Consider these four toxic assumptions:

1. “We don’t have time (or interest) to involve everyone with a stake in the decision.”

2. “People need to agree on ‘why’ to agree on ‘what’ to do.”

3. “The future will follow our design.”

4.”Fast decisions yield quick results.”

I bet if you reflect on misguided decisions in your past, you will find at least one of these driving assumptions. (Be sure to read the sections which detail how each of these assumptions work, and why they’re dangerous.)

Bad assumptions force you into situations where you are at a higher risk of making additional bad decisions to extricate yourself from the initial mistake. To be clear: Bad decisions spawn bad decisions. When enough of them pile up, they can push even thriving ventures into a death spiral.

This week, be mindful of your assumptions. When the time comes to make decisions, ask yourself if you may be harboring any toxic assumptions. A careful delay today could save your tomorrow.