Editor’s Note (December 21, 2017): Through to the end of the year, BBC Capital is bringing back some of your favourite stories from 2017.

We’ve all heard it before: to be successful, get out of bed early. After all, Apple CEO Tim Cook gets up at 3:45am, Fiat CEO Sergio Marchionne at 3:30am and Richard Branson at 5:45am – and, as we know, “the early bird catches the worm.”

But just because some successful people wake up early, does that mean it’s a trait most of them share? And if the idea of having exercised, planned your day, eaten breakfast, visualised and done one task before 8am makes you want to roll over and hit snooze ’til next Saturday, are you really doomed to a less successful life? 

Research shows that morning versus evening types show a classic left-brain versus right-brain division

For about half of us, this isn’t really an issue. It’s estimated that some 50% of the population isn’t really morning or evening-oriented, but somewhere in the middle. 

Roughly one in four of us, though, tend more toward bright-eyed early risers, and another one in four are night owls. For them, the effects can go beyond falling asleep in front of the TV at 10pm or being chronically late for work. Research shows that morning versus evening types show a classic left-brain versus right-brain division: more analytical and cooperative versus more imaginative and individualistic. 

Morning people set higher goals for themselves, plan for the future more and have a better sense of well-being

Numerous studies have found that morning people are more persistent, self-directed and agreeable. They set higher goals for themselves, plan for the future more and have a better sense of well-being. And compared to night owls, they’re less likely to be depressed, drink or smoke

Although morning types may achieve more academically, night owls tend to perform better on measures of memory, processing speed and cognitive ability, even when they have to perform those tasks in the morning. Night-time people are also more open to new experiences and seek them out more. They may be more creative (although not always). And contrary to the maxim (‘healthy, wealthy and wise’), one study showed that night owls are as healthy and wise as morning types – and a little bit wealthier. 

Still think the morning people sound more like CEO material? Don’t set your alarm for 5am just yet. As it turns out, overhauling your sleep times may not have much effect.

“If people are left to their naturally preferred times, they feel much better. They say that they are much more productive. The mental capacity they have is much broader,” says Oxford University biologist Katharina Wulff, who studies chronobiology and sleep. On the other hand, she says, pushing people too far out of their natural preference can be harmful. When they wake early, for example, night owls are still producing melatonin. “Then you disrupt it and push the body to be in the daytime mode. That can have lots of negative physiological consequences,” Wulff says, like a different sensitivity to insulin and glucose – which can cause weight gain. 

Up to 47% of it is inherited, which means if you want to know why you pop up at dawn each day (or never do), you should probably look at your parents 

In many ways, that makes sense, since research shows that our chronotype, or internal clock, is mainly biological. (Researchers even have found that the circadian rhythms of human cells in vitro correlate with the rhythms of the people they were taken from). Up to 47% of it is inherited, which means if you want to know why you pop up at dawn each day (or never do), you should probably look at your parents. One genetic factor seems to be the length of the circadian cycle: humans average a 24.2-hour clock, meaning everyone adjusts slightly each day to a 24-hour rhythm. But for night owls, the clock often runs longer – meaning that, without external cues to change, they’ll fall asleep and get up later and later over time. 

Your preference does change as you age. Children tend toward morning, with a peak shift toward night around age 20 and a slight change back toward morning at around age 50. But compared to your peers, you’ll probably always fall within the same rough part of the spectrum. 

Bright eyes 

In our rush to figure out the ‘secrets’ of success, we tend to forget a couple of things. First, not all high achievers are early risers, and not all early risers are successful. (Famous late risers include Box CEO Aaron Levie and Buzzfeed CEO Jonah Peretti, plus creatives like James Joyce, Gertrude Stein and Gustave Flaubert). 

But more importantly, in a phrase beloved by academics everywhere, correlation isn’t causation. In other words, it’s not clear that waking up early itself provides the benefit. Instead, it may be that most of us are expected to start work or school by 8 or 9am. If you’re a morning person, a combination of biological changes, from your hormones to body temperature, will get you up and at 'em way ahead of your night owl peers. That means people who enjoy rising early will be more aligned with their workday and likely to achieve more. For a night owl waking at 7am, her body still thinks she’s asleep and is acting accordingly, so she’s groggy for much longer than a morning person who wakes up at the same time. 

It may also mean that they’ve had to figure out how to be more innovative and cut corners – which may encourage their creativity and cognitive skills

Researchers also point out that because evening types often have to function when their bodies don’t want to, it makes sense that they may have worse moods or lower life satisfaction. It may also mean that they’ve had to figure out how to be more innovative and cut corners – which may encourage their creativity and cognitive skills.

 

Because the cultural stereotype is that people who go to bed and rise late are lazy, most people probably try to become morning people as much as they can. The only ones who don’t may inherently have more rebellious, or individualistic, traits. 

But shifting someone’s chronotype doesn’t necessarily change these traits. As one recent study found, even as people tried to become ‘morning’ people, it didn’t make them have a better mood or life satisfaction, suggesting these traits are “intrinsic components of the late chronotype.” 

Other research also has hinted that your sleep preference may be biologically ‘bundled’ with other characteristics. In one recent study, for example, the University of Haifa’s Neta Ram-Vlasov found that more visually-creative people had more sleep disturbances, such as waking several times at night or insomnia. Again, correlation isn’t causation, she says. But there may be a connection to genetics. “There is a dopamine receptor gene that has been previously associated with both increased creativity and also with insomnia and sleep disturbance,” she says. 

Still think you’d be better off if you shifted to becoming a morning person? Morning exposure to bright (or natural) light, avoiding artificial light at night and carefully-timed melatonin intake can help. But because you’re effectively overriding your biology, any changes take discipline and must be consistent to last. And because night owls tend to have a longer circadian cycle, putting them even more at odds with a 24-hour schedule, that can be tougher for them to achieve. 

In real terms? “The normal person may be able to handle 1.5 hours and achieve a stable entrainment,” says Wulff. Even that will require significant external input – like super-bright morning light (at least 2,000 lux), she says. 

As long as that dawn wake-up isn’t guaranteeing us CEO status, we think we’ll hit snooze on any major changes to our schedule.

To comment on this story or anything else you have seen on BBC Capital, please head over to our Facebook page or message us on Twitter.

If you liked this story, sign up for the weekly bbc.com features newsletter called "If You Only Read 6 Things This Week". A handpicked selection of stories from BBC Future, Culture, Capital and Travel, delivered to your inbox every Friday.