7 Weird Things That Happen Before You’re 7

7 Weird Things That Happen Before You’re 7


Kids are weird and not just because they do a lot of weird things, like sticking crayons up their noses or eating dirt. Kids are weird because humans go through a lot of changes between infancy and adulthood, like that whole baby teeth thing. There’s a lot going on in your body in the first couple of years that you’re alive, and some of those things are pretty frickin’ bizzare. Many babies are born with blue eyes and they can change colour until they settle on a more permanent hue Eye colour is influenced by pigmentation of the outermost region of the iris called the stroma In this case it’s a pigment called melanin which also affects your hair and skin colour The specialized cells that produce and store melanin are called melanocytes and melanin reflects and absorbs light in different ways depending on the amount of pigment and the distribution of melanocytes in the iris, which leads to different eye colours Blue eyes have almost not pigment Green or hazel eyes have some yellow and some brown pigment and brown eyes—you guessed it—have lots of brown pigment Many newborn babies especially those of Caucasian decent who generally have lower levels of melanin throughout their life don’t have much pigment in their eyes, making them look blue. Over time, in some people, the melanocytes will begin to produce more pigment leading to a slow shift in eye color throughout childhood. This usually slows down by around age five but some people may change eye colour later in life as well There’s a lot of variations because scientists estimate that around 16 genes may play a role in determining eye color In utero, your brain actually over-produces brain cells called neurons through a process called neurogenesis Before you’re born, nearly half of those brand new neurons will die off naturally, through a process called apoptosis Basically, programmed cell-death Scientists think that apoptosis is a really important part of helping your brain make the right neuronal connections to function All cells have the program, and your brains use protein signals to keep it turned off or turn it on. For example, when a developing neuron grows toward the right cell and makes a connection, called a synapse, it receives some proteins called neurotrophins, which protect against apoptosis Neurons that don’t make the right connections don’t get these neurotrophins, and die off instead By the time you’re born, your brain is mostly done with neurogenesis and apoptosis. But the wiring isn’t finished yet; your brain continues to fine-tune these synaptic connections throughout your childhood as a kid, you have way more neuronal connections than you need. Connections that are used the
most will be stabilized and protected so your brain can keep signaling with them
and the extra connections that go unused will be pruned back by the brains immune
cells called microglia. The microglia wrap around these extra connections and
break them off of the neuron, gobbling up the cell debris. This helps the neurons
focus on maintaining their stable, highly used synapses and makes way for new
synapses to connect and develop. When you’re born, your head is enormous
compared to the rest of your body. An infant’s brain is already a quarter of
the size of an adult brain, but their body mass is much, much smaller than the mass of an adult, and by the time you’re 2 your brain is already about 75% the size
of a fully-grown adult brain Now this might seem strange since we talked about
how your brain doesn’t grow many new neurons after you’re born. Turns out, your
brain keeps producing other kinds of brain cells, collectively called glia, to
help support and maintain the neurons but how can your brain grow so much when your skull is surrounding and protecting all that tissue? Well, we’ve evolved these
soft spots or fontanelles on our infant skulls, places where the skull hasn’t
yet fused together, leaving it flexible so a baby’s head can be compressed a
little bit to pass through the birth canal. Compared to other primates our
soft spots fuse relatively late in childhood at around two years old
instead of just a couple months, allowing space for the brain to gradually grow
and develop. So your giant baby head can expand to hold all of that growing brain
mass and the rest of your body can catch up to it later. Human babies grow really
slowly compared to other mammals we have a prolonged childhood and little kids
require a lot of attention and supervision it’s kinda hard to imagine
why staying little for so long could have an evolutionary advantage. Some
scientists think they figured it out, and it’s because our brains use a lot of
energy using brain imaging data a team of researchers from multiple
universities estimated how much energy our brains need at different points in
our lives. They were specifically looking at how much glucose the brain was consuming in 29 kids and
compared it to the body’s overall daily energy requirement and the glucose
consumption of seven young adult brains as a control. Surprisingly they found
that even though our brains are proportionately largest right after we’re
born that’s not when they seem to be using
the most energy. When you’re around five years old, right when your childhood
growth rate is slowest, your brain uses energy at a rate of about two-thirds of
your body’s resting metabolism. This is around the time when your brain is
really stabilizing and pruning all of those neuronal connections. So scientists
think your brain could be using so much energy doing this construction work, that
your body has to slow down other processes like growing up and, once your
brains energy consumption starts to decrease again, you’ll eventually hit the
last big growth spurt, that fun friend we call puberty. Everyone’s familiar with
the sensation of shivering basically when you get cold your brain starts
signaling your muscles to make them quickly contract and relax. The process
produces heat and warms up your body But babies under the age of around three
months haven’t developed the systems and muscle tissue needed to shiver yet, so
they have to keep warm some other way They have more of a special kind of fat
called brown fat with lots of blood vessels and energy producing cell
organelles called mitochondria. So when babies get cold, they burn brown fat
located in their chest, shoulders and backs This releases heat energy to warm them
up and this whole process is called non shivering thermogenesis. It’s essentially
the same thing that helps keep some animals warm during extended hibernation.
This is really important because babies are particularly susceptible to cold.
They can’t dress themselves or move away from cold things, so they needed a good
way to keep warm The larynx is the technical term for the
voice box. It helps you breathe without inhaling your food by closing the
epiglottis the flap of cartilage behind the tongue so food can slide right on
past to the stomach. Plus the combination of vocal cords inside the larynx and air
coming from the lungs allows us to produce speech. The human larynx is lower
down in the throat then in non-human primates and scientists think this
anatomy helps us articulate so many different sounds. It’s pretty important
for producing language which I will talk more about in a second. In infants the
larynx is positioned really high up pretty much inside of the skull which is
similar to non-human primates like chimpanzees. And this
positioning is really useful. It allows babies to breathe through their noses
while eating. Since babies aren’t very coordinated this is really important for
protecting their lungs from any liquids or food bits so they don’t choke. But by
two years of age the larynx has begun to drop into the neck so the pathways to
the lungs and stomach begin to intersect. As an adult it’s up to you to figure out
how to safely breathe and eat at the same time. Now this doesn’t sound that
interesting after all we use language every day and of course you learn it as
a kid. But that’s what makes it so cool we learn language without any formal
teaching. Linguists think the basics of language: speaking signing and linguistic
comprehension are biologically innate basically all humans can use these
skills. There are lots of different theories about how we learn language and
none of them are a really complete explanation. But scientists do think it
has something to do with experiencing language in your environment. Jean Piaget,
legendary child psychologist, was a fan of the cognitive theory. He believed that
children first developed the ability to understand the idea of a thing like the
concept of a ball or the feeling of love and then they learn how to express it in
words. Another popular theory is learning
through imitation and positive reinforcement. Children learn by
imitating adults and getting feedback on what’s right and what’s not but kids of
course can make up completely new sentences and words that they’d ever
heard before, so this theory can’t explain it all. So there’s another
possibility: the innateness of certain linguistic features. The theories that
all humans are born with some innate grammatical knowledge and just need
exposure to a primary language to start putting it into action. This could maybe
explain why all languages have things like vowels and consonants and nouns and
verbs. If we’re somehow hardwired to understand and use them, even the very
first languages could contain these basic kinds of tools. So parents always
say that kids grow up fast, but it turns out there are a lot more weirder, cooler
things to childhood development than you might have expected. Thanks for watching
this episode of scishow brought to you by our president of space Dillon Barth who would like to remind
everyone that if you want something you’ve never had, you have to do
something you’ve never done. If you want to help scishow out by being a president
of space or signing up to get some episodes a little early another patreon.com / scishow and don’t
forget to go to youtube.com slash scishow and subscribe. …learned it in
picture books and preschool cat’s meow dogs bark and ducks quack, but not all
animals use such obvious methods of communication and some of them are
downright weird

100 thoughts on “7 Weird Things That Happen Before You’re 7

  1. I'm pretty sure other observation disproves the "cognitive theory" of language as we very well know that without a proper language people become "learning disabled" as happened in deaf people before the Advent of sign languages, back when we tried to force them into learning spoken language without them having the ability to produce it.

  2. Last point is completely off base. If there's a Universal "sound log" for human language it's because simple sounds were made earliest – because there are some sounds that require less anatomic effort than others.

  3. I think the weirdest thing for me personally and my development was how my hair changed. I had super curly hair as a baby, toddler, and young child. Then at around 5, it started getting straighter, until by the time I was 6 or 7, I had totally straight hair. Then when I hit puberty? Went super curly again.

    Now that I'm done with puberty it's not QUITE as curly as it was when I was a teen, but it's still very curly. It's just…. tamer now lol

  4. I believe that the ability to articulate well doesn’t come from the placement of the larynx but the size of our brains. My brother has Chiari-1 and 2 malformations which caused so much swelling that it pushed his larynx upward, it didn’t drop until he was about nine when he had a decompression surgery. Because it hadn’t dropped he often inhaled his food and got pneumonia. He spoke fine though. Actually really well, just not often.

  5. If well-used neuronal connections are preserved in a young brain, and unused connections are 'snapped off and devoured', this must have an effect on IQ.
    The early upbringing of a child must effect it's eventual IQ.

  6. actually, when you think about it children don't make up new words, they just take sounds they already know and connect them together, same way with written language. You can't just make a new letter, you CAN make a new word, though.

  7. Interesting thought: After studying a ketogenic diet vs a carbohydrate and glucose diet, how can a child's brain energy be calculated only by glucose consumption?

  8. for #1. I'm not sure if I'm just being ignorant and all cats do this, but my kittens all had blue eyes when they were born, one cat's eyes changed to an orangey colour, another just stayed blue, and the rest ended up with brown eyes.

  9. My eyes were green and eventually moved to hazel in my early 20s.. when I was a teenager, my eyes would turn yellow quite often

  10. During the 6th section, Your Larynx Drops from Your Head into Your Throat, we mention that the high larynx position lets babies breathe while drinking, but this is a common misconception.

    Scientists put this to the test in the 1950s by giving babies barium-spiked milk and x-raying them as they drank. In those experiments, and more research done since then, they’ve consistently found that babies stop breathing when they swallow because the epiglottis seals off the larynx and the soft palate closes off the nasal cavity, like in adults.

    This misconception may be so popular because babies are actually really good at coordinating their feeding and breathing. And if they’re born full term, they can rhythmically suck, swallow, and then breathe. So, in a way, they can breathe and drink—they just can’t breathe and swallow at the exact same time.

  11. My eyes used to be very very dark brown and turned blue when I got older. My mom said the same thing happened with my aunt's eyes. So weird, especially because it's usually blue at birth, but our eyes do it the other way around, apparently.

  12. As a sufferer of childhood trauma, the neuronal connections interests me. Because, even after 20 years since the onset of the trauma, I can remember some of the worst of it so vividly, and especially the feelings I had at the time, I wonder if my brain kept those pathways open because of the stimulus. I have complex PTSD, and I've heard of theories that childhood onset of PTSD actually rewires the brain due to its plasticity at that age. It sounds like that's the connection.

  13. On the topic of language, what about those with delays? Are the innate skills still there but hiding (waiting to be coaxed out), or do they simply lack those innate skills and must learn in a different way?

  14. fun fact! cats also do the entire eye color change (born with blue eyes, change later) thing. around rthe first… 2 or so weeks after opening their eyes, kittens eye colors will normally change to a different color, unless they have white on their body (as cats need white on them to have blue eyes, normally over 30% white i think, however people are working on a breed of cat that can have blue eyes with little to no white!)

  15. Further on linguistics, it's fascinating to consider that those innate skills begin to be used in utero after development of hearing.

  16. Kittens are born with blue eyes. Then they change. Is this because in the first few weeks in the wild they would have been kept out of sunlight in the mother's den?

  17. #7 (Piaget & language development) is literally what I was studying at uni today in Developmental Psych'. Neat xx

  18. So happy you said in Utero rather than Womb. Man I hate that word. Womb makes someone sound so uneducated.

  19. You should educate yourself by true scientist, S. V. Savelyev. He knows everything about embriogenesis and heterochonicity of child development.

  20. Do something ive never done?
    Hank, i dont think either of us tried getting the soul stone before 😉

  21. our baby brain doesn't know if its an ape or a baby or a lizard so it comes with all the wiring and keeps what it ends up using a lot?

  22. Mongolian babies have black irises and eventually turned dark brown and sometimes babies are born very rarely with blue or grey eyes and eventually turns blue or hazel. At least in my experience.

  23. given the MINUSCULE amount of atoms per arrangement ……. ill wager most things occur ………

  24. omg everyone always says i'm crazy when i say i used to have blue eyes and then i show them photos of lil me

  25. There's also Critical Period Theory which states that you have to learn a language by 12 or so. This theory is supported by a really terrible case where a family left their daughter (https://en.wikipedia.org/wiki/Genie_(feral_child)) locked in a room for a well past this point and she never learned to talk correctly.

  26. My eye color changed up until I was a junior in high school. Weirdly, my eyes went from mainly brown to mainly green. I also have central heterochromia, though, which might be part of why my eye color is wacky. The genes controlling my eye color is wacky.

  27. The last I was tested my i.q was 176. While my brother I believe he is closer to 120-140….when I was an infant my parents had me listen to all kinds of music while my brother listen to a vacuum cleaner or washing machine both noises where to help us sleep I believe that they music is why I became smarter then my brother.

  28. you shouldn't pronounce the second 'p' in apoptosis, you can find the original paper describing this to see for yourself

  29. "none of them are…"

    It should be "none of them is."
    None = "no one"
    Subject = "one"
    Verb = "is"
    For subject – verb agreement.
    All else is modification

  30. I always find people talking about the genesis of language in children really interesting.

    I was a “feral kid” (not of the raised by wolves type, but of the extreme neglect/treated like an animal/raised with the family animals/as one of them type), and it took 6-8 years of speech therapy to teach me to talk fluently when that situation stopped. So I still kind of remember learning to talk (something a lot of people seem not to?) because it was later in my childhood than most and such a Weird Experience.

  31. Also, babies have more bones than adults do. Over time, their little extra bones just sort of fuse together into bigger bones.

  32. I was born with 2 of my soft spots fused.
    Surgeons had to break my skull, remove my forehead and reattach it so I could have spaces between the plates so my skull could grow properly

  33. kids have more neurons than they need….

    maybe that just means we're all very understimulated during our formative years?

  34. If they were looking at how much glucose brain was consuming, then they have been off by factor of 4 for all new-born to end of beat feeding children, as they are effectively in ketosis and 75% of energy usage of brain comes from ketones and only at most 25% from glucose.
    How scientist can miss such actually all known fact is escaping me.

  35. Using brown fat (and white fat too, especially when circumstances are right) to warm up strictly requires ketosis. Lack of ketones shut down mitochondria decoupling. Any excess of glucose shut down decoupling too.
    Well I do not have problem with cold. I can take cold bath (no hot or even warm water involved at all) for as long as warm bath. No, not cold shower, but cold bath. I would not shiver at all. The higher ketones, the longer I can lay fully immersed in cold water.

  36. Brown fat is not for burning.
    Brown fat is not energy storage, as such, but heating device.
    I just imagine that you have cardboard box and you do not use it for insulation, but instead you burn for few minutes of heat. This is stupid. Human body is not stupid and won't burn its own heating device for few minutes of heat.

  37. This video was basically the first month of my developmental neuroscience class lol, except for the pronunciation of apoptosis (not a hard a, same sound as 'actually', that was one of the things drilled into our heads)

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