Last October, when fear about Ebola was at its height in the US, we saw the phrase, “out of an abundance of caution” being used to justify just about anything under the sun. Want to ban kids from schools because they shared a continental land mass with Ebola victims? Go ahead and do it out of an abundance of caution. Want to confine anyone who gets sick on an airplane to the bathroom for a whole flight? Go ahead and do it out of an abundance of caution. In fact, out of an abundance of caution, we should really plan to never read anything online again, so that we can be sure that the phrase never takes hold in our brains. Now that the fear around Ebola has died down, it’s a saner moment to think about what that phrase really does. It allows businesses, schools, leaders in the government, and others in charge to enact policies that are scientifically unfounded but potentially irrational and, sometimes, to infringe upon the rights of others. We are hardly the first to complain about over-reaching policies set out of an abundance of caution, but it’s a recurring problem worth considering. Making decisions in a responsible way means weighing potential outcomes with the chances that those outcomes might occur. The phrase, “out of an abundance of caution,” is often used when explaining an action that isn’t necessary, but is going to be done anyway because you want to be extra careful. Unfortunately, this throws the whole decision making process for a loop, because it assumes that there are no consequences for overly cautious and unnecessary actions. Yet these actions always have a cost – in money, resources, time and, sometimes, civil liberties. Further, using the phrase undermines the science-based messages surrounding risk. During the Ebola outbreak, public health officials repeatedly cited science-based messages that the disease could only be transmitted by people experiencing symptoms of the disease and that there was no science-based rationale for putting asymptomatic individuals in quarantine. The Louisiana Department of Health and Hospitals highlighted these points in a manual on Ebola (the link to the document has since been removed from the website) then noted that quarantine would be used in Louisiana regardless of risk category.What the phrase really suggests to the public is that these actions were actually needed, otherwise they wouldn’t be done. Either something is necessary, and should be done, or is unnecessary and shouldn’t be done. One justification for acting out of an abundance of caution is calming public fears. But do these actions actually calm public fears, or do they make a threat seem bigger than it really is? A better approach is to be transparent about what we know about risks, what science says we should do to minimize those risks, and maybe most importantly, be clear about what we don’t know. A transparent approach to communicating risk has been shown again and again to be more effective than trying to obfuscate the facts and make one sweeping decision “out of an abundance of caution.”Using the phrase to justify our actions is tempting, especially when we are a little scared and not sure what to do. But let’s be honest with ourselves and others about the risks we face and act accordingly, rather than out of an abundance of caution. It would be crazy to think that thousands of Americans could be rounded up, out an abundance of caution, to spend the next few years in the middle of our country in internment camps. Yet, that happened to thousands of Japanese-American citizens during World War II. So let’s avoid falling into the “out of abundance of caution” mindset. It’s often used to justify actions on the margins of advisability, and in reality it usually serves to signal a dangerous combination of fear and rashness.