Jean Piaget’s Theory of Cognitive Development

in this video we're going to dive into developmental psychology essentially child psychology and we're gonna start by discussing Jean Piaget the famous Swiss psychologist and his theory of cognitive development cognitive development is simply the study of how we acquire the ability to learn to think to communicate and to remember and theories of cognitive development vary in three different ways some theories are staged theories they assume that development progresses in distinct stages think for example of a caterpillar turning into a cocoon turning into a butterfly other theories assume that development progresses continuously development is sort of like a tree growing right gradually and slowly over time without distinct qualitatively different stages the next dimension along which theories of cognitive development vary is that some theories are domain general theories whereas others are domain specific what do I mean by this well think about the different domains of cognition domains of thought you can think about mathematical reasoning versus linguistic reasoning language ability versus thinking morally versus thinking abstractly versus thinking concretely all of these different domains so some theories assume the domain progresses the same for all those different domains whereas others assume that development is specific to each of those different domains last but not least we have differences between theories in the proposed source of learning essentially what causes cognitive development one underlies learning over time well Jean Piaget who's sadly no longer with us has essentially considered the father of developmental psychology because he developed the first major theory of cognitive development so where does he stack up in terms of the dimensions we discussed on the previous slide well Piaget was first and foremost a stage theorist he believed the development passed through distinct stages and that's what I'm going to focus on in this video his account was a domain general account so he believed that regardless of the specific domain it was really these stages that underlied development regardless of whether you're talking about math or this or that it's all just dependent on these stages and he believed that learning was experience based so he believed that children learned they develop cognitively through experience with the world and one of his biggest contributions was viewing children as little scientists he didn't see children as sort of you know dumb little objects that are just blobs going throughout the world no he viewed them as little scientists that experiment on the world in order to understand it better even something simple like how babies stick toys and objects in their mouths right some may view that as just a silly little baby thing but he viewed it as experimentation in the world a great way to learn about the physical properties of new objects that you haven't encountered before is actually to put it in your mouth it's a great way to learn sort of again what the properties of that object are the texture right the heaviness all sorts and things like that and so he viewed even a simple act like that as experimentation with the world so let's talk about Sean PJ's theory of cognitive development again this was a stage theory and there were four distinct stages that he believed children pass through in order universally regardless of where you're from and we're going to focus on these four stages first we have the sensory motor stage then the pre-operational stage the concrete operational stage and finally the formal operational stage let's talk about the sensory motor stage the sensory motor stage is a stage lasting from zero to two years of age in which the world is experienced through senses and actions hence sensory motor stage and it's marked by a focus on the here and now with no thought beyond immediate physical experiences that is children cannot form mental representations according to Piaget in this stage I remember learning about mental representations in my introductory psychology class and having no idea what it really meant and I think the best way to illustrate what mental representations means is through an example so what I want you to do is simply picture your favorite food form a mental image of your favorite food whatever it looks like really create a picture of it in your mind if you're able to do that you have the ability to form mental representations that's all it is it's being able to hold something in your mind that isn't directly in front of you call the image to mind call the thought to mind picture it right creating an image of it even if it's not there that's a mental representation of the object you're thinking about and Piaget believed that in the sensorimotor stage children lack this ability another key sort of limitation of children in the sensorimotor stage is that they lack object permanence they lack the ability to understand that objects are permanent and they continue to exist even when hidden from view for example if you were to take a sensorimotor child and you were to take an object and place that object behind a barrier that the child cannot see through the child would be confused the child might think that that object was simply gone it vanished it no longer exists and they would go about their day this is an illustration that children in the stage lack object permanence now we will come back to this because we're going to challenge that idea in a little bit but again we're just discussing PJ's theory so that's the sensory motor stage now let's focus on the pre-operational stage the pre-operational stage is a stage lasting from two to six years of age in which children use words and images to represent things meaning they can now form mental representations but they lack logical reasoning and there are two main limitations of children in this stage first of all children in the pre-operational stage lack the ability to perform what Piaget called operations and I'm going to describe that in just a moment second of all children are limited by ego centrism meaning they view the world from only their point of view this is both a physical literal thing like they think everyone sees what they see but also a conceptual thing if you for example ask a child in the pre-operational stage what their favorite snack is and they say Jesus and you say okay well what do you think my favorite snack is what do you think they'll say they'll say Jesus what do you think Bob's favorite snack is cheez-its right they think everybody has the same preference as they do which is again egocentrism and you can again try this on somebody in the pre-operational stage and chances are they'll do this but let's get back to the idea of operations you're looking at in the bottom middle of the screen here is a sort of depiction of one of PJ's classic tasks the conservation of liquid tasks so what you're looking at is two cups same size filled with liquid filled with water to the same level and then you see a third cup which is a different size it's obviously much thinner and taller and longer and what you do is simple first you show the children that the two first cups have the same amount of liquid and then you simply pour one of the cups into the thinner longer cup and then you ask children which cup has more liquid the one on the left or the one on the right or are they the same hopefully you realize as an adult who's passed the pre-operational stage that they have the same amount of liquid right even though the one on the right looks taller we know that it's thinner and we saw at the start that the same amount of liquid was there children in the pre-operational stage fail this task and they mistakenly say that the cup on the right has more liquid demonstrating that they are pre-operational so let's progress onto the concrete operational stage the concrete operational stage is a stage lasting from 7 to 11 years of age roughly in which children finally understand those concrete events and analogies meaning they can pass PJ's conservation of liquid tasks as well as other tasks that Piaget devised that were similar but in the concrete operational stage everything is concrete so they lack abstract logic and moral reasoning abilities which leads us to the final stage the formal operational stage this is a stage that emerges in adolescence so it's about 12 years of age according to Piaget in which children can finally think abstractly and they can reason hypothetically so no longer are they bound by ego centrism and a lack of object permanence no longer do they fail concrete operational tasks and finally they can reason about hypothetical situations they can think about moral dilemmas and they can reason about them as an adult would according to Piaget so that's PJ's theory in a nutshell what are some limitations of his theory because even though he's again the father of development of psychology his work spurred on years and years and decades of research there were some key limitations to PJ's theory and we now know that some of what he believed was a little off the first limitation of PJ's theory is that development is more continuous than Piaget believed as far as we know and for most domains there aren't specific stages that children really pass through instead development progresses gradually over time now there are some exceptions we have some stages that children pass through when learning to count for example so certain aspects of numerical understanding but overall development is continuous next we know that his tests had really high task demands and as we'll see in a moment when you lower task demands meaning you ask less of children children reveal a much deeper understanding that Piaget thought and finally this is kind of a funny one his entire theory was based on his observations of his three children I think that's pretty hilarious that he developed such a huge theory that changed the face of psychology and created an entire sub discipline of psychology all based on experimentation and observation of three children that's pretty funny but in comes Rene bears on Rene Barr John is what I consider the mother of developmental psychology if Jean Piaget is the father no relation but she changed the face of developmental psychology as well because she challenged a lot of pjs beliefs by testing them using new methods with lower task demands and what she revealed is that children performed much better than Piaget believed and at earlier ages when you simply asked them to do less Rene Bergeron is a wonderful person I had the opportunity to work with her a little bit as a graduate student at the University of Illinois and she really does do great work so let me tell you a little bit about the violation of expectation paradigm that Rene bars on pioneered in this paradigm all you asked children to do is to simply look now I'm going to tell you about a study that Rene bars on used to challenge PJ's notion that children don't develop an understanding of object permanence until years into life and instead what we're gonna see is that using this VOE method Rene Bergeron showed that infants as young as six months of age and younger in newer studies understand that objects continue to exist when hidden from view so all she's gonna do is have children watch a scene unfold and we're simply gonna measure how long children look at the scene how engaged they are how surprised they are if we violate their expectations about the world they should look longer this is the key assumption of the task so let me illustrate by describing one specific study so first we habituate children to a scene what does this mean think back to habituation from long ago we get them bored with the scene we show it over and over and over just to get them familiar with the situation and then they look away they get bored they get distracted all of that stuff so here's the scene there's a little Minnie Mouse doll and there's a screen right just two key objects very simple that's it and what they see is they see the Minnie Mouse doll excuse me sort of pass behind the screen over and over and over so the Minnie Mouse doll passes behind the screen pops out the other side again again again again if you see that you know 1020 times you're gonna get really bored once they're bored children are randomly assigned these are infants minds you young babies are randomly assigned to one of two conditions either a possible event or as we'll see in a moment an impossible event in the possible event there's sort of a window cut out of the screen and then children see Minnie Mouse pass through pass behind the screen as before this is perfectly possible there's nothing earth-shattering about this it doesn't violate any physical properties about the world right the window isn't low enough for Minnie Mouse's head to sort of pop out the top of it and so there's nothing crazy going on okay there's just a window cut out but that window is sort of irrelevant now in the impossible event there's a door and the door is very relevant because when Minnie Mouse passes behind this screen she doesn't pass through the door you don't see her right so from children's from the children's perspective who are participating in the study you see Minnie Mouse enter one end and then sort of teleport and come out the other end and this is an impossible event right we don't believe if objects are permanent if we have that understanding we don't believe that objects can teleport from one place to the next and again what we're doing is we're measuring on these two key trials between subjects of some infants are in the possible event some infancy the impossible event we're looking at how long infants look at these events and what we found what Rene Barzun found is that infants look significantly longer at the impossible event than the possible event they look longer at the event on the right than the event on the left and this makes a lot of sense if children at this age have an understanding of object permanence they realize that objects cannot teleport and so they're very surprised by the impossible event they're shocked and confused by the impossible event and so they look significantly longer at it on the left the possible event is simply less interesting because it doesn't violate any expectations about the world so through this study and many other studies Rene Bergeron showed that children do have an understanding of object permanence at a younger age than Piaget believed challenging PJ's theory of cognitive development