Today, I want to talk about something that on the surface may seem trivial, but it's actually a huge deal and that is school start times because when I tell you that you might not only be severely impacting your students mental capacity and intelligence both in the moment and the future, but also impacting their physical and mental health.

I'm not exaggerating.

Let me put it bluntly.

School needs to start later, at least for a high school and university age students.

And I don't mean later as in later in the year, I mean later as in not so freaking early in the morning, but to understand why we first have to understand sleep before a baby is even born and up to around the first year of its life infants spend much of their time in rem sleep otherwise known as rapid eye movement.

This is a stage we dream in and it's during this rem sleep that babies are building up huge amounts of neural networks and connections in their brain.

But soon after this time period there's a sharp decline in rem sleep and an exponential rise in deep non rem sleep that continues to rise until around puberty.

And this non rem sleep is actually responsible for fine tuning our brains instead of building up more and more neurons and connections.

It actually prunes and makes the brain more efficient and effective.

It's basically taking the mold that early life created and sculpting it based on your life experiences and interactions and studies have shown that this non rem sleep is linked to the development of critical thinking, reasoning and cognitive skills.

Now, some of you might be screaming, reasoning skills, critical thinking in teens and you'd be right in noticing that teens aren't exactly known for these things.

But ironically the development of the brain during this non rem increase happens from back to front, literally the back of the brain, which manages visual and spatial perception develops first and this growth eventually makes its way to the front of the brain or the frontal lobe last, which finally enables critical and rational thought.

This is why it sometimes feels that kid's brains aren't exactly working or keeping up with the rest of their development.

Thing is when non rem is minimized or removed, things can go really wrong in studies of mice and cats deprived of sleep, the brain development is stopped.

In fact, many psychiatric disorders like schizophrenia bipolar and major depression are considered disorders of abnormal development.

Studies on schizophrenia in particular have shown that there is a 2 to 3 fold reduction in non rem sleep in teenagers that suffer from it.

To top it all off, teens actually need more sleep than their adult counterparts.

So if they're not getting enough hours of sleep, then they aren't going to be getting the optimal amount of non rem sleep, which can hamper development.

Now I know what you're asking how does this correlate to the time that school starts canteens, just go to bed early, like the rest of us and get a long enough sleep and if not, what time should school be starting at Before we get to that answer.

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So why does the specific time matter so much, isn't it more relevant how much sleep kids are getting?

Yes and no.

The first thing you need to know is that as kids move into puberty, their circadian rhythm completely shifts our circadian rhythm is the name given to our internal clock that controls your body's sleep wake cycle.

In other words, it helps define when you feel tired and want to sleep versus when you feel at your most alert.

This rhythm is of course different for everyone.

We all have our unique prototype, which is why some people are considered early birds and others are night owls, but in general, adults share a propensity to wake and sleep at roughly the same time.

The thing is one of the biggest factors defining our circadian rhythm is our age.

Young kids before puberty not only need the most sleep, but tend to have a really early schedule.

They become sleepy early in the evening and wake up earlier than adults typically.

But as we hit puberty, the timing is shifted forward past even their parents by as much as 2 to 4 hours, meaning we want to stay up much later.

And this change is seen across all adolescents, regardless of culture or geography, where a nine year old will typically fall asleep around nine PM by the age of 16.

That's actually often the hour of peak wakefulness, asking a teenager to go to bed at 10 PM is like asking an adult to go to sleep at seven p.m. In the same vein, waking up at seven AM for a teen is the same as waking up around four a.m. For an adult.

And I'm pretty sure all of us don't want to be seen at four AM, let alone have to use our brains at four a.m. A Lot of parents believe that teens are making a conscious decision to stay up later and that if they just went to bed earlier they wouldn't be so tired.

But the truth is even if they do go to bed earlier chances are they'll just be lying in bed awake until their body naturally winds down but not embracing this biological timing.

On top of the fact that teens need more sleep to begin with risks developmental brain abnormalities and mental illness.

And we have experimental evidence to show it later.

Start times increased class attendance reduced behavioral and psychological problems and decreased substance and alcohol abuse.

Longer sleep is directly correlated to better grades and teens across the board and higher I.

Q.

S.

And studies on identical twins show that by the age of 10 the twin with the longer sleep pattern has superior intellectual abilities with more expansive vocabulary to and schools that have tested later Start times have seen a huge shift.

A school in Minnesota that changed from a 7 25 AM start to 8:30 a.m. Found that verbal S.

A.

T.

Scores rose by over 150.

Well math S.

A.

T.

Scores went up by over 50.

And what we talked about the importance of non rem quality sleep in young adults.

That's not to say rem sleep isn't also really important.

Studies in the 19 sixties that deprived young adults of Rem found that by the third day of extreme deprivation, participants started to exhibit signs of psychosis.

They were anxious, moody and started to hallucinate and became paranoid.

Rem also becomes longer and more prominent in the later parts of your sleep, meaning if you cut your sleep short, your disproportionately impacting the amount of RAM you're getting.

Life expectancy has also been shown to increase with later start times.

So the number one cause of death in teens is road traffic accidents which have been linked directly to sleep desperation.

When one county in Wyoming changed their start time from 7:25 a.m. To 8:55 a.m. They saw a 70% decrease in traffic accidents in the affected age group.

So why do circadian rhythms stray so far in adolescence?

The prevailing socio evolutionary theory right now is that it allows teens and young adults to start gaining their independence from their parents, but in small increments for several hours a day, kids can operate on their own or with their peer group away from adults, but it's not a full removal from parental supervision.

During this stage, they get to practice becoming their own individual.

The truth is only a century ago in America.

Most schools started around nine a.m. And 95% of students woke up without an alarm.

Now in the US, 80% of schools begin before 8:15 a.m. And 50% of those who start before 7 20 am, not to mention the increasing impact of TVs, computers and phones in the bedroom.

It's no wonder kids are more tired than ever at the end of the day, the evidence is overwhelming that later start times around nine a.m. Or so are not only preferred by students but lead to improvements in basically every single metric for measuring their progress by in school.

In the words of dr walker who wrote the book why we sleep, which was the primary source for this episode.

We're too often focused on what sleep is taking away from our teenagers without stopping to think about what it may be adding.

I hope we can change.

I hope we can break the parent to child transmission of sleep neglect and remove what the exhausted fatigue brains of our youth are so painfully starved of when sleep is abundant, minds flourish when it's deficient.

They don't hope this video has been informative and useful, especially if you are a parent or a teacher or someone who manages a school.

And if you're a student, send this to your teachers right now, send this to your administrators and let them know.

It's not a joke.

Sleep is a huge part of our lives and so important for intellectual capacities and our physical health.

And they would do well to think about that when they start your school.

Thanks again for watching.

Make sure you like the video, subscribe if you want more and we'll see you next time for some more science piece.