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Course: MCAT > Unit 12
Lesson 2: Human development- Human physiological development
- Egg, sperm, and fertilization
- Early embryogenesis - Cleavage, blastulation, gastrulation, and neurulation
- Implantation
- Germ layer derivatives
- Gestation
- Major motor milestones
- Motor development
- Neonatal reflexes
- Physical development in adolescence
- Brain changes during adolescence
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Major motor milestones
Motor development in infants follows a predictable sequence of milestones. From lifting their heads at 2-4 months to walking alone at 11-15 months, each stage has a wide age range. Individual differences are normal, and parents should consult a doctor for any concerns about their child's motor development.
Created by Brooke Miller.
Want to join the conversation?
- Has anyone actually come across questions regarding milestones on the MCAT?(26 votes)
- I couldnt understand anything . it is not clear , very fast,(5 votes)
- I have a question: for MCAT how should i approach this. Should i memorize it or is it just an FYI.(10 votes)
- are we supposed to know specific time frames or just general idea of what comes after what?(7 votes)
- Are there differences in motor milestones between genders?(3 votes)
- I didn't do an exhaustive search but on the info i found there is no differences between genders in terms of the motor skills discussed in this video. However, later in development differences begin to occur such as in ball skills and other fine motor movements.(3 votes)
Video transcript
- [Instructor] One thing that I find really fascinating about development, is that it tends to follow
a pretty stable course. And this is especially
true of motor development. Children come into the world with a number of pre-programmed motor skills
that we refer to as reflexes, and these are automatic,
involuntary motor responses. But it isn't only involuntary movement that children develop. Over time, they also develop
voluntary movement as well. And when they do, these movements develop at a very particular time and
in a very particular order. And, in general, infants develop at an
incredibly rapid pace. And, actually, it happens so quickly that we generally talk
about infant development in terms of months and not years. And so I want to talk a
little bit about those stages of motor development and
exactly when they happen. And to do this, I have this graph. And I've drawn in our axes ahead of time. So on our x-axis we have age and months, but I've also put some years on there, so six months is half a
year, 12 months is a year, and 18 months is one and a half years. And on the y-axis we have a
list of major motor milestones. And we usually think
about motor development in terms of these motor milestones. And as you might expect, motor development moves from
the simplest movements first, and then ends with more complex movements. And the first major milestone happens between two and four months. And this is when infants
can lift their heads up on their own and hold their
chests up with arm support. Also around this time, from
about two months to five months, children also gain the
ability to roll over. Once that milestone is reached, the infant is next able
to sit up without support, and that happens during about
five months to eight months. And around that same time, from about five months to 10 months, they gain the ability to stand
while holding onto furniture or people for support. The next motor milestone is reached between six months and 11 months. And that's when the infant
can pull themselves up into a standing position on their own, without any help from parents. And then between seven
months and 12 months, so seven months and one year, children begin to be able to crawl. And between seven months and 13 months, they also begin to be able to walk while holding onto furniture. Most kids figure out how to
stand up while on their own from between 10 and 14 months. And then finally, at between
11 months to 15 months of age, they begin to be able to walk alone. And all of this happens in
a year, or just over a year, and it is really incredible
when you think about it. But one thing that you might
notice about this graph is that I gave it a
rather wide range of ages for all of the different motor milestones. Because according to
what I've written here, it seems that some children might be able to walk with support
before other children, who are a few months older than them, might be able to crawl. But that is actually how it works. And the normal time in
which a skill can develop really is that wide. And this might be
different from other things that you have learned or read online, which might point to more specific times that these milestones should be reached. But the reality is that there are a ton of individual differences. And those numbers that you see typically represent the median age,
meaning that by definition, half of the children
will develop that skill before that time, and half of
them will develop it after. So parents should not
panic if they have a child who doesn't develop a skill
right when a book says that they should, and, similarly, parents shouldn't assume
that their child is a genius because they develop a skill
slightly before a given age. But, as always, if you do have a question
about motor development, it would be best to ask your doctor.