Walking through nature, by contrast, exposes you to what lead author Marc Berman calls “inherently fascinating stimuli,” using sunsets as an example. These stimuli “invoke attention modestly, allowing focused-attention mechanisms a chance to replenish.” Put another way, when walking through nature, you’re freed from having to direct your attention, as there are few challenges to navigate (like crowded street crossings), and experience enough interesting stimuli to keep your mind sufficiently occupied to avoid the need to actively aim your attention. This state allows your directed attention resources time to replenish. After fifty minutes of such replenishment, the subjects enjoyed a boost in their concentration.
(You might, of course, argue that perhaps being outside watching a sunset puts people in a good mood, and being in a good mood is what really helps performance on these tasks. But in a sadistic twist, the researchers debunked that hypothesis by repeating the experiment in the harsh Ann Arbor winter. Walking outside in brutal cold conditions didn’t put the subjects in a good mood, but they still ended up doing better on concentration tasks.)
What’s important to our purpose is observing that the implications of ART expand beyond the benefits of nature. The core mechanism of this theory is the idea that you can restore your ability to direct your attention if you give this activity a rest. Walking in nature provides such a mental respite, but so, too, can any number of relaxing activities so long as they provide similar “inherently fascinating stimuli” and freedom from directed concentration. Having a casual conversation with a friend, listening to music while making dinner, playing a game with your kids, going for a run—the types of activities that will fill your time in the evening if you enforce a work shutdown—play the same attention-restoring role as walking in nature.
On the other hand, if you keep interrupting your evening to check and respond to e-mail, or put aside a few hours after dinner to catch up on an approaching deadline, you’re robbing your directed attention centers of the uninterrupted rest they need for restoration. Even if these work dashes consume only a small amount of time, they prevent you from reaching the levels of deeper relaxation in which attention restoration can occur. Only the confidence that you’re done with work until the next day can convince your brain to downshift to the level where it can begin to recharge for the next day to follow. Put another way, trying to squeeze a little more work out of your evenings might reduce your effectiveness the next day enough that you end up getting less done than if you had instead respected a shutdown.
Reason #3: The Work That Evening Downtime Replaces Is Usually Not That Important
The final argument for maintaining a clear endpoint to your workday requires us to return briefly to Anders Ericsson, the inventor of deliberate practice theory. As you might recall from Part 1, deliberate practice is the systematic stretching of your ability for a given skill. It is the activity required to get better at something. Deep work and deliberate practice, as I’ve argued, overlap substantially. For our purposes here we can use deliberate practice as a general-purpose standin for cognitively demanding efforts.
In Ericsson’s seminal 1993 paper on the topic, titled “The Role of Deliberate Practice in the Acquisition of Expert Performance,” he dedicates a section to reviewing what the research literature reveals about an individual’s capacity for cognitively demanding work. Ericsson notes that for a novice, somewhere around an hour a day of intense concentration seems to be a limit, while for experts this number can expand to as many as four hours—but rarely more.
One of the studies cited, for example, catalogs the practice habits of a group of elite violin players training at Berlin’s Universit?t der Künste. This study found the elite players average around three and a half hours per day in a state of deliberate practice, usually separated into two distinct periods. The less accomplished players spent less time in a state of depth.
The implication of these results is that your capacity for deep work in a given day is limited. If you’re careful about your schedule (using, for example, the type of productivity strategies described in Rule #4), you should hit your daily deep work capacity during your workday. It follows, therefore, that by evening, you’re beyond the point where you can continue to effectively work deeply. Any work you do fit into the night, therefore, won’t be the type of high-value activities that really advance your career; your efforts will instead likely be confined to low-value shallow tasks (executed at a slow, low-energy pace). By deferring evening work, in other words, you’re not missing out on much of importance.
The three reasons just described support the general strategy of maintaining a strict endpoint to your workday. Let’s conclude by filling in some details concerning implementation.
To succeed with this strategy, you must first accept the commitment that once your workday shuts down, you cannot allow even the smallest incursion of professional concerns into your field of attention. This includes, crucially, checking e-mail, as well as browsing work-related websites. In both cases, even a brief intrusion of work can generate a self-reinforcing stream of distraction that impedes the shutdown advantages described earlier for a long time to follow (most people are familiar, for example, with the experience of glancing at an alarming e-mail on a Saturday morning and then having its implications haunt your thoughts for the rest of the weekend).
Another key commitment for succeeding with this strategy is to support your commitment to shutting down with a strict shutdown ritual that you use at the end of the workday to maximize the probability that you succeed. In more detail, this ritual should ensure that every incomplete task, goal, or project has been reviewed and that for each you have confirmed that either (1) you have a plan you trust for its completion, or (2) it’s captured in a place where it will be revisited when the time is right. The process should be an algorithm: a series of steps you always conduct, one after another. When you’re done, have a set phrase you say that indicates completion (to end my own ritual, I say, “Shutdown complete”). This final step sounds cheesy, but it provides a simple cue to your mind that it’s safe to release work-related thoughts for the rest of the day.
To make this suggestion more concrete, let me walk through the steps of my own shutdown ritual (which I first developed around the time I was writing my doctoral dissertation, and have deployed, in one form or another, ever since). The first thing I do is take a final look at my e-mail inbox to ensure that there’s nothing requiring an urgent response before the day ends. The next thing I do is transfer any new tasks that are on my mind or were scribbled down earlier in the day into my official task lists. (I use Google Docs for storing my task lists, as I like the ability to access them from any computer—but the technology here isn’t really relevant.) Once I have these task lists open, I quickly skim every task in every list, and then look at the next few days on my calendar. These two actions ensure that there’s nothing urgent I’m forgetting or any important deadlines or appointments sneaking up on me. I have, at this point, reviewed everything that’s on my professional plate. To end the ritual, I use this information to make a rough plan for the next day. Once the plan is created, I say, “Shutdown complete,” and my work thoughts are done for the day.