HealthyChildren.org - Cognitive Development In Preschool Children has a good article in Cognitive Development, which means the construction of though process, remembering past experiences, problem solving, and decision making.
The article goes as follows:
Cognitive Development In Preschool Children
Your three-year-old will spend most of her waking hours questioning everything that happens around her. She loves to ask “Why do I have to . . . ?” and she’ll pay close attention to your answers as long as they’re simple and to the point. Don’t feel that you have to explain your rules fully; she can’t yet understand such reasoning and isn’t interested in it anyway. If you try to have this kind of “serious” conversation, you’ll see her stare into space or turn her attention to more entertaining matters, such as a toy across the room or a truck passing outside the window. Instead, telling her to do something “because it’s good for you” or “so you don’t get hurt” will make more sense to her than a detailed explanation.
Your child’s more abstract “why” questions may be more difficult, partly because there may be hundreds of them each day and also because some of them have no answers—or none that you know. If the question is “Why does the sun shine?” or “Why can’t the dog talk to me?” you can answer that you don’t know, or invite her to look into the question further by finding a book about the sun or about dogs. Be sure to take these questions seriously. As you do, you help broaden your child’s knowledge, feed her curiosity, and teach her to think more clearly.
When your three-year-old is faced with specific learning challenges, you’ll find her reasoning still rather one-sided. She can’t yet see an issue from two angles, nor can she solve problems that require her to look at more than one factor at the same time. For example, if you take two equal cups of water and pour one into a short, fat container and the other into a tall, skinny one, she’ll probably say the tall container holds more water than the short. Even if she sees the two equal cups to start with and watches you pour, she’ll come up with the same answer. By her logic, the taller container is “bigger” and therefore must hold more. At around age seven, children finally understand that they have to look at multiple aspects of a problem before arriving at an answer.
At about three years of age, your child’s sense of time will become much clearer. Now she’ll know her own daily routine and will try hard to figure out the routines of others. For example, she may eagerly watch for the mail carrier who arrives every day, but be perplexed that trash is picked up only one day out of seven. She’ll understand that certain special events, such as holidays and birthdays, occur every once in a while, but even if she can tell you how old she is, she’ll have no real sense of the length of a year.
But if you have any questions or concerns about your three-year-old’s development, you should discuss it with your pediatrician. If he agrees that there is reason for concern, he will refer your child for further testing.
By age four, your child is beginning to explore many basic concepts that will be taught in greater detail in school. For example, he now understands that the day is divided into morning, afternoon, and night, and that there are different seasons. By the time he’s five and entering kindergarten, he may know some days of the week and that each day is measured in hours and minutes. He also may comprehend the essential ideas of counting, the alphabet, size relationships (big versus small), and the names of geometric shapes.
There are many good children’s books that illustrate these concepts, but don’t feel compelled to rush things. There’s no advantage to him learning them this early, and if he feels pressured to perform now, he actually may resist learning when he gets to school.
The best approach is to offer your child a wide range of learning opportunities. For instance, this is the perfect age to introduce him to zoos and museums, if you haven’t done so already. Many museums have special sections designed for children, where he can actively experience the learning process. At the same time, you should respect his special interests and talents. If your child seems very artistic, take him to art museums and galleries, or let him try a preschool art class. Also, if you know an artist, take him for a visit so he can see what a studio is like. If he’s most interested in machines and dinosaurs, take him to the natural history museum, help him learn to build models, and provide him with construction kits that allow him to create his own machines. Whatever his interests, you can use books to help answer his questions and open his horizons even further. At this age, then, your child should be discovering the joy of learning so that he will be self- motivated when his formal education begins.
You’ll also find that, in addition to exploring practical ideas, your four-year-old probably will ask many “universal” questions about subjects such as the origin of the world, death and dying, and the composition of the sun and the sky. Now, for example, is when you’ll hear the classic question “Why is the sky blue?” Like so many other parents, you may have trouble answering these questions, particularly in simple language your child will understand. As you grapple with these issues, don’t make up answers; rely instead on children’s books that deal with them. Your local library should be able to recommend age-appropriate books to help you.