We’re all biased, and I know that like anyone else, when I read data that reinforces my beliefs that it tends to stick with me.

That’s exactly what happened when I watched this TED talk from neuroscientist Jeff Iliff and the always excellent Brain Picking blog article about The Science of Internal Time, Social Jet Lag, and Why You’re So Tired – Debunking the social stigma around late risers, or what Einstein has to do with teens’ risk for smoking.

You know from this post that I love my sleep, but I’ve never heard about social jet lag.

“It is the disconnect between our internal, biological time and social time — defined by our work schedules and social engagements —a kind of chronic exhaustion resembling the symptoms of jet lag. “

Wow it was there in just 4min from Jessa Gamble’s TED Talk

“When people are living without any sort of artificial light at all, they sleep twice every night. They go to bed around 8:00 p.m. until midnight and then again, they sleep from about 2:00 a.m. until sunrise. And in-between, they have a couple of hours of sort of meditative quiet in bed.”

I was so happy to get explanations about what I’ve felt for so long in my teen and adult life. Indeed “each of us possesses a different chronotype” and I happened to be a late chronotype.

“This myth that early risers are good people and that late risers are lazy has its reasons and merits in rural societies but becomes questionable in a modern 24/7 society. The old moral is so prevalent, however, that it still dominates our beliefs, even in modern times. The postman doesn’t think for a second that the young man might have worked until the early morning hours because he is a night-shift worker or for other reasons. He labels healthy young people who sleep into the day as lazy — as long sleepers. This attitude is reflected in the frequent use of the word-pair early birds and long sleepers [in the media].“

This judgment is based on the assumption that everyone goes to bed at the same time, which we increasingly do not.

These scissors of sleep are exactly what I was referring to in my previous post, catching up on sleep during weekends & vacations. Brain Picking continues to explains that Roenneberg pointed out that:

“During puberty and adolescence humans become true night owls”

“adolescents’ internal time is shifted so they don’t find sleep before the small hours of the night“

and that “there is a great disconnect between teenagers’ biological abilities and our social expectations of them”.

One more time, this is well summarized by Sleep researcher Wendy Troxel in her TED talk “Why school should start later for teens”.

I wish the data had been available some 25-30 years ago when I needed school time to start later.

Now, one of my favorite author Daniel Pink (author of Drive, see my post here), has a new tip: a nappuccino, ie. having a coffee right before a 10-20min nap; then when you wake up the caffeine just kicks in. Thanks Eat Sleep Work Repeat and here’s Daniel Pink explaining it himself: https://www.danpink.com/pinkcast/pinkcast-2-15-this-is-when-you-should-drink-coffee/