If you’ve worked in sales, you know that positivity has transformative power. A positive attitude endears you to both clients and coworkers. It not only boosts individual performance, but spreads amongst team members, lifting numbers and morale. The most proactive managers are aware of its influence and model a positive outlook themselves, thereby inspiring their employees.
But cultivating positivity can be difficult when you work in a competitive, high-pressure, and rejection-saturated atmosphere—as every salesperson does. Like a plant, a positive attitude needs to be nurtured so that it can thrive. That’s why, in order to stay positive, salespeople should work on positivity’s foundation: sleep.
In order to talk about positivity, we need to talk about the differences between emotion, mood, and attitude. Here’s a quick primer before we get into the science.
The fact that positivity correlates with great sales performance is almost intuitive. We want to be around positive people; we find them more charismatic and convincing. In fact, banks are more likely to give loans to optimistic entrepreneurs—the ones that dream big.
Whether you’re a manager, a coworker, or a client, you’d probably rather do business with a salesperson who broadcasts a positive, can-do attitude than one who doesn’t. The science backs our intuition with evidence: positive people find greater sales success.
The broaden-and-build theory of positive emotions covers almost all of the above points, stating that “positive emotions promote discovery of novel and creative actions, ideas and social bonds,” all of which are valuable to a sales team.
Finally, it’s important to note that positivity appears to breed achievement more than achievement breeds positivity! A review of more than 200 studies on the subject found that positive emotions not only tend to precede markers of success in work and life, but also encourage the “desirable behaviors and cognitions” that lead to success, such as high energy, creativity, and sociability.
This is why a positive attitude should be considered an essential first step to sales success, rather than a byproduct of sales success.
We know that getting sufficient sleep has benefits across the physical, cognitive, and emotional spectrums, and that it can dramatically boost work performance. But it appears that our emotions are impacted by sleep to the greatest degree: meta-analysis has found that sleep deprivation affects mood notably more than it does cognitive or motor performance.
The strength of this sleep-emotion link has been well-documented. Your perception of how well you've slept is a reliable predictor of your mood the next day, and the long-term effects of sleep on mood are incredibly pronounced. Nearly all mood disorders occur alongside “one or more sleep abnormalities,” prompting scientists to theorize that enough lack of sleep could actually be causing these disorders.
Given how tightly sleep and mood are wound together, it’s safe to say that sleep plays a huge role in the attitude you bring to work.
Sleep loss affects your mood in several ways, and all of these consequences combine to prevent the positive mindset you want.
When you don’t get sleep, you simply feel crummy—emotionally as well as physically. One study cut its participants’ nightly sleep down to 4–5 hours a night, then measured the effects of the sleep deprivation on mood. The participants experienced a rise in overall mood disturbance, and felt more confused, tense, and anxious in particular. It was only when they caught up with two nights of unimpaired sleep that they reported a dramatic uptick in mood.
Unfortunately, if you’re getting more than 4–5 hours a night but still less than your sleep need, your mood will probably still drop. After sleeping 5–6 hours a night for an extended period of time, medical residents said that they not only felt “moodier,” but that their ability to care for patients had become impaired!
When you’re well-rested, your emotions are well-regulated. You can respond to negative circumstances with patience and poise. But when you lose sleep, your ability to control your emotions lessens. You’re more irritable, and liable to lash out with emotion that’s disproportionate to the situation.
One study looked at how sleep-deprived subjects responded to different types of stressors, all of which are pertinent to the sales workplace: “cognitive tasks, time pressure, and feedback about performance.” The study varied the severity of these stressors to try and gauge whether sleep-deprived people had a lower threshold for troubling situations. Indeed, compared to a control group, the sleep-deprived participants reacted with more stress, anger, and anxiety to the triggers designed to be low-stress.
Worryingly, sleep deprivation can disrupt our emotional regulation so much that we can't tell the difference between something negative and something neutral. Researchers have found that sleep-deprived people will react with the same strength of emotion when presented with mundane “distractors” (for example, an image of a spoon) as when they look at negative ones (for example, an image of an injury). These results suggest that when you’ve lost a lot of sleep, you can become strongly emotionally affected by situations that you normally wouldn’t even register as stressful.
Moreover, your reactive state becomes apparent in how you express yourself, whether you want it to or not—it even influences your tone of voice. It's a good bet that you'll sound more prickly and antagonistic when you haven't slept, upping the risk of strained relationships in and outside the office.
When you’re prone to overreaction and volatility, positive thinking is far from your mind. But what about when something positive does occur—could it lift you out of your sleep-deprived funk? Unfortunately, the answer seems to be no: lack of sleep can blunt your response to positive achievements, so you may not even be able to appreciate success when it happens.
Sleep loss promotes stress, and stress promotes sleep loss. Once you’re caught in this bidirectional cycle, it can be exceedingly hard to escape. The repercussions of stress push you away from positivity and towards the negative, intrusive thoughts of cognitive interference. So, you’re not just moody and reactive—you’re unfocused and more prone to error, too.
Stress and sleep loss also appear to team up against your more balanced, level-headed self. Scientists think that increased stress may be a large part of the reason why emotional regulation and self-control are lowered in sleep-deprived people. Essentially, you’re being hit by two emotionally disruptive forces at once: the destabilizing impact of sleep loss, plus the stress caused by that sleep loss.
When sleep loss has you feeling negative, reactive, and stressed—the opposite of positive, in other words—it’s almost impossible to keep those emotions to yourself. You and your coworkers are all influenced by emotional contagion: the transference of emotional expressions and emotions themselves between people.
Research tells us that we all subconsciously mimic the emotional cues that others advertise. These cues include vocal patterns, postures, gestures, facial expressions, and more. Once you adopt the cues yourself, you also experience the associated emotions. So, if one person in the office has a bad attitude due to sleep loss, it’s a sure bet that they’ll spread it around, amplifying negativity throughout the office—and among the team’s clients, too.
This is especially worrisome for team managers, whose leadership methods affect everyone under their charge.
We’ve established that it’s impossible to untangle sleep from mood, and that sleep loss disturbs your mood substantially. But why? What causes these relationships? The science supports a few interlocking theories:
After a night or more of insufficient sleep and all of the negative thinking it creates, you’re probably going to worry about the same thing happening the next night … and the next. By believing that the trend will continue, you’re upping your stress and perpetuating the cycle. Negativity breeds negativity, and a bad attitude feeds on itself.
Your brain’s prefrontal cortex is a great regulator. It’s responsible for all the complex executive functioning tasks that bear on your work, like focusing, planning, and decision-making. It also has a connection to the amygdala, the region of the brain that governs your emotional reactions to both positive and negative stimuli. The prefrontal cortex (or PFC) is thought to hold the reins on the amygdala, inhibiting it before it becomes too engaged, and preventing a person from too much reactivity.
Sleep, and particularly REM (rapid eye movement) sleep, plays a crucial role in maintaining this connection. Studies show that achieving REM sleep seems to initiate a sort of emotional reset in the brain, “optimally preparing the organism for next-day social and emotional functioning.” During this phase of sleep, levels of the stress hormone norepinephrine are at their absolute minimum, priming the body to be less reactive to future stressors. REM sleep also appears to help maintain the PFC’s control over the amygdala.
When you lose sleep, however, the connection between the PFC and the amygdala appears to loosen. The PFC can’t inhibit the amygdala as much, and your emotional regulation goes haywire. One study showed that a single night without sleep caused reactivity in the amygdala to jump up by 60% when subjects looked at “emotionally negative pictures.”
This disconnect between the PFC and the amygdala is thought to be the driving force behind the rise in reactivity following lack of sleep.
Ego depletion theory states that each of us has a reservoir of discipline that we use when exercising self-control. Discipline, as you well know, is crucial to success in sales: you need to be disciplined about pursuing prospects, following up with clients, monitoring your various projects, and all else.
Whenever you're exercising your willpower, you’re dipping into your discipline-reservoir. But the reservoir is finite—it depletes over time, like fuel, which means your self-control can fail if you’ve been taxing it. Research tells us that glucose is an essential part of this system, and that having less glucose in your bloodstream can make your reservoir drain more quickly.
Here’s where sleep comes in: sleep deprivation and poor sleep quality both negatively affect the body’s metabolization of glucose. Basically, studies suggest that if you don’t sleep, you won’t rebuild the cognitive resources necessary for full self-control, and your moods will be more volatile and less positive.
A lack of self-control also kicks off its own vicious cycle of sleep loss. After all, you need self-control to tell yourself to go to bed, even when it’s tempting to stay up later. If your mental resources are depleted, you won’t be able to sleep when you need to, which leads to a further lack of self-control … on and on, until the cycle is broken.
Based on all of the above information, sleep holds the key to nurturing and maintaining positivity. Just as your mood plummets when you’re sleep-deprived, it lifts when you prioritize paying off your sleep debt—the difference between the amount of sleep you’ve gotten and the amount of sleep your body needs, calculated over the last 14 days.
Why focus on sleep first? Studies show that sleep has a more powerful impact on mood than vice versa. It would be tougher to try and goad yourself into a positive mindset and then catch up on sleep. Rather, you should aim to sleep more so that you can shift your attitude.
The more you sleep, the more thorough your emotional reset becomes. Your brain’s resources are replenished, your glucose metabolism evens out, and you’re in a better place to respond to both positive and negative developments during the day.
At the same time, your overall vigor—the energy, liveliness, and enthusiasm you project—rises by up to 64%. Decreasing your sleep debt by 8 hours can also reduce the negativity in your vocal patterns by up to 67%, which bodes well for your interactions with coworkers and clients alike.
Thankfully, other consequences of sleep deprivation reverse into benefits when you get sufficient sleep. High sleep quality produces more positive affect, which in turn combats stress, breaking the stress/sleep-loss cycle.
Emotional contagion, too, works both ways. People with positive attitudes spread them to others, increasing cooperation and decreasing conflict, paving the way for a better work environment. Research indicates that this positive emotional contagion is just as powerful as the negative kind.
Ready to promote more sleep and positivity in your sales team? We recommend a two-pronged approach.
Positive thinking is especially critical right now, as stressors like the COVID-19 pandemic threaten to overwhelm us. As for the sales world, a certain amount of unpredictability and stress is par for the course. Some people adopt a cutthroat mindset, thinking that cynicism is key to getting ahead. But don't be fooled. If you want to reach more sales success, start with habits that promote a positive attitude. Encourage your team to reduce sleep debt--moods will brighten, just as their numbers rise.
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