· 

In addition to rapid physical growth, young children also exhibit significant development of their cognitive abilities.

Jean Piaget thought that children's ability to understand objects, such as learning that a rattle makes a noise when shaken was a cognitive skill that develops slowly as a child matures and interacts with the environment.

Today, developmental psychologists think Piaget was incorrect.

Researchers have found that even very young children understand objects and how they work long before they have experience with those objects. For example, children as young as three months of age demonstrated knowledge of the properties of objects that they had only viewed and did not have prior experience with.

In a study by Renée Baillargeon, infants three months of age were shown a truck rolling down a track and behind a screen. The box, which appeared solid but was actually hollow, was placed next to the track.

The truck rolled past the box as would be expected. Then the box was placed on the track to block the path of the truck. When the truck was rolled down the track this time, it continued unimpeded. The infants spent significantly more time looking at this impossible event.

Baillargeon concluded that they knew solid objects cannot pass through each other.

Baillargeon's findings suggest that very young children have an understanding of objects and how they work, which Piaget would have said is beyond their cognitive abilities due to their limited experiences in the world.

Just as there are physical milestones that we expect children to reach, there are also cognitive milestones. It is helpful to be aware of these milestones as children gain new abilities to think, problem solve, and communicate.

At around six to nine months of age, infants shake their head 'No', and at around nine to twelve months they respond to verbal requests to do things like 'Wave bye-bye' or 'Blow a kiss'.

We can expect children to grasp the concept that objects continue to exist even when they are not in sight by around eight months of age. Because children aged between twelve and twenty-four months have mastered object permanence, they enjoy games like hide and seek, and they realise that when someone leaves the room they will come back.

Toddlers also point to pictures in books and look in appropriate places when you ask them to find objects.

At around three to five years of age, preschool-age children also make steady progress in cognitive development. Not only can they count, name colors, and tell you their name and age, but they can also make some decisions on their own, such as choosing an outfit to wear.

Preschool-age children understand basic time concepts and sequencing, like before and after, and they can predict what will happen next in a story. They also begin to enjoy the use of humor in stories.

Because they can think symbolically, they enjoy pretend play and inventing elaborate characters and scenarios. One of the most common examples of their cognitive growth is their blossoming curiosity. Preschool-age children love to ask 'Why?'

An important cognitive change occurs in children this age, where they come to understand that people have thoughts, feelings, and beliefs that are different from their own.

This new understanding is known as theory-of-mind. Children can use this skill to tease others, persuade their parents to purchase a candy bar, or understand why a sibling might be angry.

When children develop theory-of-mind, they can recognise that others have false beliefs.

Between six and eleven years of age, cognitive skills continue to expand in middle and late childhood. Thought processes become more logical and organised when dealing with concrete information.

Children at this age understand concepts such as the past, present, and future, giving them the ability to plan and work toward goals.

Additionally, they can process complex ideas such as addition and subtraction and cause-and- effect relationships.

However, children's attention spans tend to be very limited until they are around eleven years

of age. After that point, it begins to improve through adulthood.

Language acquisition is also an aspect of cognitive development, with the order in which children learn language structures is consistent across children and cultures.

Starting before birth, babies begin to develop language and communication skills. At birth, babies apparently recognise their mother's voice and can discriminate between the languages spoken by their mothers and foreign languages, and they show preferences for faces that are moving in synchrony with audible language

As babies, children communicate information through gesturing long before they speak, and there is some evidence that gesture usage predicts subsequent language development.

In terms of producing spoken language, babies begin to coo almost immediately. Cooing is a one-syllable combination of a consonant and a vowel sound. Interestingly, babies replicate sounds from their own languages.

A baby whose parents speak French will coo in a different tone than a baby whose parents speak Spanish, Urdu or any other language. After cooing, the baby starts to babble. Babbling begins with repeating a syllable, such as 'ma-ma', 'da-da', or 'ba-ba'.

When a baby is about twelve months of age, we expect them to say their first word for meaning, and to start combining words for meaning at about eighteen months.

At about two years of age, a toddler uses between fifty and two hundred words. By three years of age, they have a vocabulary of up to one thousand words and can speak in sentences.

During the early childhood years, children's vocabulary increases at a rapid pace. This is sometimes referred to as the 'vocabulary spurt' and has been claimed to involve an expansion in vocabulary at a rate of ten to twenty new words per week.

Recent research may indicate that while some children experience these spurts, it is far from universal. It has been estimated that children five years of age understand about six thousand words, speak two thousand words, and can define words and question their meanings.

They can rhyme and name the days of the week. Children seven years of age speak fluently and use slang and clichés.

What accounts for such dramatic language learning by children?

Behaviourist B. F. Skinner thought that we learn language in response to reinforcement or feedback, such as through parental approval or through being understood. For example, when a two-year-old child asks for juice, he might say, 'Me juice', to which his mother might respond by giving him a cup of apple juice.

Noam Chomsky criticised Skinner's theory and proposed that we are all born with an innate

capacity to learn language. Chomsky called this mechanism a language acquisition device. Both Chomsky and Skinner are correct, as we are a product of both nature and nurture.

Researchers now believe that language acquisition is partially inborn and partially learned through our interactions with our linguistic environment.