Every Saturday morning, while my husband JD is eating his cereal and attempting to fully awaken, I ambush him with the list of household chores and errands I've been making all week (and saving for when he'll be home to help me.) Every single time, an argument ensues. At its core is JD's unshakeable belief that any task, no matter how complex or difficult, can be completed in about 15 minutes. "Let's go out and have some fun, " he'll say, "and we'll tackle that stuff when we get back this afternoon." "But there won't be enough time!" I reply, with mounting frustration. "It will be fine," he says. More often than not, he is wrong.
As much as I enjoy giving him a hard time about his total inability to judge how long something will take, the truth is that most people aren't much better at it. In fact, human beings are generally pretty lousy when it comes to estimating the time they will need to complete a task. Psychologists refer to this as the planning fallacy, and it's an all too common problem - one with the very real potential to screw up our plans and keep us from reaching our goals.
Studies show that the planning fallacy can be attributed to several different biases we have when estimating how long it will take to do just about anything. First, we routinely fail to consider our own past experiences while planning. When my husband tells me it will take him 15 minutes to vacuum the carpets, he is ignoring the fact that it took him an hour to do it last time. And as any professor can tell you, most college seniors, after four straight years of paper-writing, still can't seem to figure out how long it will take them to write a 10-page paper. We just don't take our past into account the way we should when thinking about our future.
Second, we ignore the very real possibility that things won't go as planned - our future plans tend to be "best-case scenarios." So running to the store for a new vacuum cleaner might take 15 minutes - if there is no traffic, if they carry the model we're looking for, if we find it right away, and if there aren't long lines at the register.
Lastly, we don't think about all the steps or subcomponents that make up the task, and consider how long each part of the task will take. When you think about painting a room, you may picture yourself using a roller to quickly slap the paint on the walls, and think that it won't take much time at all - neglecting to consider how you'll first have to move or cover the furniture, tape all the fixtures and window frames, do all the edging by hand, and so on.
So while we all tend to be prone to the planning fallacy to some extent, some of us fall into its trap more often than others. People in positions of power, for example, are particularly vulnerable, because feeling powerful tends to focus us on getting what we want, ignoring the potential obstacles that stand in our way. A recent set of studies by Mario Weick and Ana Guinote shows that such a narrow focus does indeed turn powerful people into very poor planners.
In one study, half of the student participants were made to feel powerful (by being told that their opinion would influence the course requirements established for incoming students). Next, all students were asked to estimate when they would finish an upcoming major assignment. Everyone was overly-optimistic, but powerful students were significantly more so. Powerful students estimated that they would finish their assignments 2.5 days before they actually did, while the control group was on average only 1.5 days late. So feeling powerful makes you think you'll take a whole day less to complete the assignment than you would have guessed had you been feeling a little more ordinary.
A second study induced feelings of power by having some of the participants recall a time in their past when they felt very powerful, and this produced a similar result. Powerful participants estimated that it would take them only 4 minutes to complete a proofreading task that actually took 9 minutes, compared to the control group's estimate of 6.5 minutes.
In a third study, participants who were made to feel powerful thought it would take them less time to write an essay, get ready for an evening out, shop at the supermarket, and prepare a 3 course meal, than the control group. Importantly, these effects completely disappeared when powerful participants were explicitly told to recall how much time these activities had taken them in the past, and use that information to make their estimates. So when powerful people are forced to focus on all the relevant information, their planning is far more accurate.
When you're making a plan and estimating how long it will take, be sure to stop and
1) consider how long it has taken you in the past,
2) identify the ways in which things might not go as planned, and
3) spell out all the steps you will need to take to get it done.
This is particularly important when you are in a position of power, so make sure that there are safeguards or reminders in place to help you to consider all the information you should. Otherwise, you may fall victim to the everything-takes-15-minutes kind of optimism that can lead to disaster. (Yet another reason my husband is so fortunate to have married me, as I frequently point out to him.)
M. Weick & A. Guinote (2010) How long will it take? Power biases time predictions. Journal of Experimental Social Psychology, in press.