1896 was an exceptionally good year for developmental psychology. In August of that year, Jean Piaget was born in a small town in Switzerland. Three months later in that very same year in November, Lev Vygotsky was born in a similar small town in Belarus.

Jean Piaget

Piaget was a very precocious child scientifically, and at the age of 15 he had already published several papers on the mollusk. You can imagine that it was quite a surprise to fellow scientists who considered him to be somewhat of an expert in the field to find out that he was actually just a boy.

After these initial scientific endeavors, he moved to the university where he studied philosophy and natural history. After that, he moved to Paris to work in the lab of Alfred Binet who was actually working at the school and trying to develop intelligence test for children.

Piaget helped out in delivering these tests to children, and what he discovered when he analysed the data is not only did children make more mistakes than adults do, which was expected, but also that they made the same mistake at the same age. They systematically make the same mistake at the same age.

That gave Piaget the insight that actually children develop in a different way than adults do, and they learn in a different way. This helped him to develop the first comprehensive account of cognitive development.

Children learn differently from adults

Before Piaget, we all thought children were just like small adults. They learned in the same way. They were just less capable of doing so. Piaget turned that idea around and said, "No, children are completely different." That's why we're still talking about Piaget nowadays.

Many of his theories are actually criticised now, but just because he came up with this first comprehensive account of cognitive development, that's why we're still talking about him.

For a refresher, consider revisiting for more information on Piaget's a theory of cognitive development that unfolds in four stages: sensorimotor, preoperational, concrete operational, and formal operational.Lev Vygotsky

We know a lot less about Lev Vygotsky. We know that he studied law at Moscow State University. Other than that, we know very little of his studies.

After that he moved to his old hometown where he worked in schools and orphanages to work with children. There he went to one single conference abroad, and he got offered a job in Moscow. He moved to Moscow, and there he worked on his thesis on the psychology of art.

It's only after the thesis that he actually started working on developmental psychology, which was not known like that, back then. He focussed on how children acquire these higher cognitive functions, and he focussed on, more specifically, how social interactions shape our development.

Comparing Piaget with Vygotsky

Piaget believed that development preceded learning, so in order to learn, we need to be at the stage in development that we can actually do that specific bit of learning. He believed that there are four different stages.

The first is the sensorimotor stage. The second, the preoperational stage, the third is the concrete operational stage, and the last is the formal operational stage.

Piaget believed that children self-initiated this learning and the development, so it was completely self-contained within the child.

Lev Vygotsky, on the other hand, believed that learning preceded development. In order to develop, you need to learn skills, and that allows you to continue on to later stages. He also believed it is more a continuous process than something that happens in different stages.

You proceed with your learning in a continuous fashion. You go up to a certain level that you can achieve on your own, and then with the help of your parents or teachers, you can go just a tiny bit further. That's the zone of proximal development, the bit of learning that you cannot achieve on your own, but you can with the help of others. It's a cooperative learning type of development.

Vygotsky didn't quite believe so much in self-initiated development, but he believed that the socio-cultural environment was very important to drive development.

For an example, consider watching on YouTube, where the Vygotsky's theory is explained, and shows its influence on teaching and development.

There's also overlap between the theories of Piaget and Vygotsky. They were developing this in a similar time, and both were constructivists. That means that they believed that the children, themselves, took actively part in their own development. They didn't just passively absorb some information, but they actually went out and acquired it. They interacted with the environment. Infants also are believed to have this basic ability to develop, and that the development proceeds in a specific order.

Now, because of his untimely death at the age of 37, and also because his writings were mostly in Russian, much of his work was unknown for a long time, and still is.

There is an additional problem, and the work we know him most well for is the work 'Mind in Society,' but the book was actually never written by Lev Vygotsky. It was a compilation of different writings he did in the past, but it was never intended to be a book.

Because of the fact that Lev Vygotsky's work was so much less known, there are a lot less followers of his theories, and specifically newer theories that build up on his old theories. Most current theories are based on Piaget's work.

Criticisms of Piaget's work

Piaget's work was criticised on three main points. One is that it's not clear why children develop over time. Piaget said they do, in four specific stages, but he didn't explain why.

Also what is ignored is that there are different domains in which you can be good or bad. For example, you can be good in mathematics or bad in language. The third one is that he believed that it was a universal process, so each child goes through these processes in the same way, at the same speed and that clearly doesn't really explain the individual differences that are present in development.

How do these new theories attack these criticisms?

One is, to explain why we go through this developmental trajectory, people nowadays hypothesise about some kind of general capacity that develops over time. It's somewhat like working memory so how many items can we hold in our mind. That explains how we can develop, because the general capacity is initially small, and grows over time.

For example, initially you might be able to hold zero items in mind, so you can only process the stimuli that's you're currently seeing. If you can hold one item in mind, you could also process that stimulus when it's actually out of sight, and just in your mind, so that might be able to allow you to have object permanence. If you can hold two or three or more items in mind, obviously you can do more complex operations.

The other problem is that Piaget's theory did not focus on the different potential domains in which you could be good or bad. Current theories include the possibilities to grow independently in one domain, whereas you might be lagging on the other domain.

The last one, the individual differences, are also explained both by the difference in this general capacity to grow, and the domain-specific developments that could be present or not. Both of these elements could be influenced by the socioeconomic environment in which you grow up, such as Vygotsky hypothesised.

Learning domains, general and specific

In fact, nowadays theories don't only include domain-general aspects like Piaget did, or domain-specific ones like more recent theories, but actually very often the theories include both the domain-general and a domain specific aspect.

The domain-general aspects allow us to explain why children generally follow the same trajectory over time, and the domain-specific ones explain how individual differences arise in how well we are in certain domains, like language or mathematics skills.

The nice thing about this domain-general and domain-specific components, and including both of them, is that it's actually corresponding very well with what we have recently learned about the brain. The brain is also composed of domain-specific areas.

The brain is sort of modular, where it has certain areas that are good at processing language and other areas that are good at doing mathematics. Then also it has, in the front of the brain, areas that are important in these domain-general things like attention or working memory.

What's interesting here is that it also allows us to investigate interactions between behaviour and brain. It's not that we are dictated by what our brain is like at the moment, but we can actually influence how the brain develops by, for example, training. If we train at a certain task, that specific area in the brain actually grows.

There's still a lot to learn

We've come quite far from the early ideas of Piaget, and it's mostly due to recent developments in brain imaging, but we still have quite a bit to go. But we get farther and farther in our understanding of development in children.

One of the interesting aspects is now to apply that knowledge. For example, in educational settings. That's something that people are working on continuously. As we get more knowledge, hopefully that will get better and better.