When my son Michael was old enough to talk, and being an eager but naive dad, I decided to bring Michael to my educational psychology class to demonstrate to my students "how children learn". In one task I poured water from a tall drinking glass to a wide glass pie plate, which according to Michael changed the "amount" of water— there was less now than it was in the pie plate. I told him that, on the contrary, the amount of water had stayed the same whether it was in the glass or the pie plate. He looked at me a bit strangely, but complied with my point of view— agreeing at first that, yes, the amount had stayed the same. But by the end of the class session he had reverted to his original position: there was less water, he said, when it was poured into the pie plate compared to being poured into the drinking glass. So much for demonstrating "learning"!
Learning is generally defined as relatively permanent changes in behavior, skills, knowledge, or attitudes resulting from identifiable psychological or social experiences. A key feature is permanence: changes do not count as learning if they are temporary. You do not "learn" a phone number if you forget it the minute after you dial the number; you do not "learn" to eat vegetables if you only do it when forced. The change has to last. Notice, though, that learning can be physical, social, or emotional as well as cognitive. You do not "learn" to sneeze simply by catching cold, but you do learn many skills and behaviors that are physically based, such as riding a bicycle or throwing a ball. You can also learn to like (or dislike) a person, even though this change may not happen deliberately.
Each year after that first visit to my students, while Michael was still a preschooler, I returned with him to my educational psychology class to do the same "learning demonstrations". And each year Michael came along happily, but would again fail the task about the drinking glass and the pie plate. He would comply briefly if I "suggested" that the amount of water stayed the same no matter which way it was poured, but in the end he would still assert that the amount had changed. He was not learning this bit of conventional knowledge, in spite of my repeated efforts.
But the year he turned six, things changed. When I told him it was time to visit my educational psychology class again, he readily agreed and asked: "Are you going to ask me about the water in the drinking glass and pie plate again?" I said yes, I was indeed planning to do that task again. "That's good", he responded, "because I know that the amount stays the same even after you pour it. But do you want me to fake it this time? For your students' sake?"