We’ve all heard ‘Early to bed, early to rise makes a man healthy, wealthy and wise’. But what evidence did Benjamin Franklin have when he said it? Is it true the hours of sleep you get before, rather than after, midnight contribute more to your health and wellbeing?

Is it really worth getting up early? Image credit Jack Langton via Flickr

Nighty night, sleep tight

Most parents I know prioritise getting their kids to bed early. We all know only too well how kids fare if they’re short on sleep: hello tears and tantrums. You probably have a good sense of how sleep deprivation affects you too and it’s never pretty. If you’ve ever been tempted to find out how long you can go without sleep before you go crazy, don’t do it. But this post isn’t about the benefits of getting enough sleep. Let’s just all agree everyone needs somewhere between six and nine hours of sleep to function (kids need a lot more). What I’m interested in is whether it makes a difference when you get your hours of sleep. Do us grown-ups need to put ourselves to bed early too?

We all have particular sleep patterns: I’ve written before about night owls and early birds. Which sleep group you belong to depends on things like when you like to get up, how alert you feel in the morning and when you normally get tired. At this point I should probably out myself as the extreme early bird I am. I’ve learned from years of trial and error that I feel a million times better if I both go to bed and get up ridiculously early. I can get exactly the same number of hours of sleep starting after midnight and feel lousy. But am I just weird? (Friends, don’t answer that). Or is there some truth to Benjamin Franklin’s edict?

Healthy?

Is there any evidence morning people are healthier? The short answer is yes. In one study, 2,200 Australians aged 9 to 16 were put into categories according to their natural sleep and wake times. Even though they slept for the same total time, compared to those in the early bed/early rise group, late bed/risers were 1.5 times more likely to be obese and twice as likely to be physically inactive.

In a study of 250 healthy men aged under 60, it didn’t matter how much total sleep they got, but men who went to bed before midnight had fewer signs of future heart disease: their arteries were healthier. And you probably won’t be surprised to hear night owls consume more alcohol, nicotine and caffeine than early birds. Early risers still drink caffeine, but less of it, and in tea rather than coffee or cola. A large study of Finnish twins found night owls were much more likely to be current and lifelong smokers.

In a fascinating twist, researchers have identified a difference in the brain structure of larks and owls: the hippocampus of night owls has a smaller volume than in early birds. The hippocampus is important for memory and emotion and a reduction in hippocampus volume has been linked to depression. But other studies have found no link between better health and early rising.

Wealthy? Happy? Wise?

There hasn’t been a lot of research into whether early birds are wealthier. One study from the late 1990s did look at the income level of more than 1200 people and suggests Franklin got it wrong: on average, night owls earned more. But a different study of almost 1000 men found no relationship between sleeping patterns and wealth. I think the jury’s out on this one. But there has been some research on the personality of people with different sleep patterns.

Are morning people happier than night owls? In a Canadian study, adults who were early birds reported being much happier and more satisfied with life than night owls of the same age. We know people who stay up late are more likely to worry and have repetitive negative thoughts: sometimes it’s much better just to go to bed. A study of 15,000 adolescents found those going to bed at midnight or later were 24% more likely to suffer from depression and 20% more likely to consider suicide.

Early birds also tend to be more proactive, and several studies have shown night owls procrastinate more. In a personality study of more than 1200 people, early birds were more agreeable and conscientious than those used to burning the midnight oil.

Ok, so what about wise; are early birds smarter? No, not so fast. In a study of 420 people linking standard intelligence test scores and sleep habits, night owls came out on top in the brain stakes. In another study of 200 Masters students, night owls got significantly higher scores on the infamous GMAT (Graduate Management Admission Test). But in a study of German medical students, the timing of sleep had more of an effect on exam results than the length or quality of the sleep. Going to bed earlier resulted in better exam results. A different study of US college students found those who did best academically were early birds too. There’s no simple answer.

Should you make the switch?

Standard school and work hours tend to suit early birds better and if you’re a night owl who wants to switch, you almost certainly can. On the proviso that you’re willing to embrace new habits, like turning off your phone at night. But unless you have to, should you? A study of Major League Baseball players in the US tells an interesting tale. Baseballers who are morning people play better overall than night owl players. But if you look a bit closer, at the timing of the games, the story changes: yes, early birds play better in daytime games. But in games played in the evening, night owls do better.

Maybe the moral of the story is simply to sleep and wake up at whatever times feel right for you. There’s nothing wrong with being a night owl.

But I’m going to continue to embrace my inner early bird. Unless of course it turns out the secret to wealth is staying up late.

Links and stuff

• Questionnaire: are you a night owl or an early bird?
• New Yorker: Snoozers are, in fact losers
• The Atlantic: Society is messing with your sleep
• Selection of TED talks about sleep
• How much sleep do you need at different ages