Myth #1: Multitasking is critical in a world of infinite demand.

This myth is based on the assumption that human beings are capable of doing two cognitive tasks at the same time. We’re not. Instead, we learn to move rapidly between tasks. When we’re doing one, we’re actually not even aware of the other.

If you’re on a conference call, for example, and you turn your attention to an incoming email, you’re missing what’s happening on the call as long as you’re checking your email. Equally important, you’re incurring something called “switching time.” That’s the time it takes to shift from one cognitive activity to another.

On average, according to researcher David Meyer, switching time increases the amount of time it takes to finish the primary task you were working on by an average of 25 percent. In short, juggling activities is incredibly inefficient.

Difficult as it is to focus in the face of the endless distractions we all now face, it’s far and away the most effective way to get work done. The worst thing you can do as a boss is to insist that your people constantly check their email.

Myth #2: A little bit of anxiety helps us perform better.

Think for a moment about how you feel when you’re performing at your best. What adjectives come to mind? Almost invariably they’re positive ones. Anxiety may be a source of energy, and even motivation, but it comes with significant costs.

The more anxious we feel, the less clearly and imaginatively we think, and the more reactive and impulsive we become. That’s not good for you, and it also has huge implications if you’re in a supervisory role.

As a boss, your energy has a disproportionate impact on those you lead, by virtue of your authority. Put bluntly, any time your behavior increases someone’s anxiety — or prompts any negative emotions, for that matter — they’re less likely to perform effectively.

The more positive your energy is, the more positive their energy is likely to be, and the better the likely outcome.

Myth #3: Creativity is genetically inherited, and it’s impossible to teach.

In a global economy characterized by unprecedented competitiveness and constant change, nearly every CEO hungers for ways to drive more innovation. Unfortunately, most CEOs don’t think of themselves as creative, and they share with the rest of us a deeply ingrained belief that creativity is mostly inborn and magical.

Ironically, researchers have developed a surprising degree of consensus about the stages of creativity and how to approach them. Our educational system and most company cultures favor reward the rational, analytic, deductive left hemisphere thinking. We pay scant attention to intentionally cultivating the more visual, intuitive, big picture capacities of the right hemisphere.

As it turns out, the creative process moves back and forth between left and right hemisphere dominance. Creativity is actually about using the whole brain more flexibly. This process unfolds in a far more systematic — and teachable — way than we ordinarily imagine. People can quickly learn to access the hemisphere of the brain that serves them best at each stage of the creative process — and to generate truly original ideas.

Myth #4: The best way to get more work done is to work longer hours.

No single myth is more destructive to employers and employees than this one. The reason is that we’re not designed to operate like computers — at high speeds, continuously, for long periods of time.

Instead, human beings are designed to pulse intermittently between spending and renewing energy. Great performers — and enlightened leaders — recognize that it’s not the number of hours people work that determines the value they create, but rather the energy they bring to whatever hours they work.

Rather than systematically burning down our reservoir of energy as the day wears on, as most of us do, intermittent renewal makes it possible to keep our energy steady all day long. Strategically alternating periods of intense focus with intermittent renewal, at least every 90 minutes, makes it possible to get more done, in less time, more sustainably.

Want to test the assumption? Choose the most challenging task on your agenda before you go to sleep each night over the next week. Set aside 60 to 90 minutes at the start of the following day to focus on the activity you’ve chosen.

Choose a designated start and stop time, and do your best to allow no interruptions. (It helps to turn off your email.) Succeed and it will almost surely be your most productive period of the day. When you’re done, reward yourself by taking a true renewal break.