Intellectual Development (By Jean Piaget’s)

This is explained under four stages:

1. Sensorimotor period (extends from birth through roughly age two): During this period, a child learns how to modify reflexes to make them more adaptive, to coordinate actions, to retrieve hidden objects, and, eventually, to begin representing information mentally.

2. Preoperational (runs approximately from age two years to age seven years): In this period a child develops language and mental imagery and learns to focus on single perceptual dimensions, such as color and size. 

3. Concrete-operational period (ranges from about age 7years to age 12years): During this time a child develops conservation skills, which enable him to recognize that things that may appear to be different are actually the same For example, suppose that water is poured from a wide short cup into a tall narrow one. If a preoperational child is asked which cup has more water, such child will say that the second cup does (the tall thin one); a concrete-operational child, however, will recognize that the amount of water in the cup must be the same. 

4. Formal-operational period (which begins at about age 12 years and continues throughout life): The formal-operational child develops thinking skills in all logical combinations and learns to think with abstract concepts. For example, a child in the concrete-operational period will have great difficulty determining all the possible orderings of four digits, such as 3-7-5-8. The child who has reached the formal-operational stage, however, will adopt a strategy of systematically varying alternations of digits, starting perhaps with the last digit and working toward the first. This systematic way of thinking is not normally possible for those in the concrete-operational period.

Intelligence Quotient

Intelligence quotient is a standard measure of an individual’s intelligence level based on psychological tests. In other words intelligence quotient is a measure of a person's reasoning ability.

Individual`s level in intelligence

Human Memory

Human memory is our ability to encode, store, retain and subsequently recall information and past experiences in the human brain.

The Memory Process

1. Encoding (or registration): the process of receiving, processing, and combining information. Encoding allows information from the outside world to reach our senses in the forms of chemical and physical stimuli. In this first stage we must change the information so that we may put the memory into the encoding process.

2. Storage: the creation of a permanent record of the encoded information. Storage is the second memory stage or process in which we maintain information over periods of time.

3. Retrieval (or recall, or recognition): the calling back of stored information in response to some cue for use in a process or activity. We must locate it and return it to our consciousness. Some retrieval attempts may be effortless due to the type of information.

Problems can occur at any stage of the process, leading to anything from forgetfulness to amnesia. Distraction can prevent us from encoding information initially; information might not be stored properly, or might not move from short-term to long-term storage; and/or we might not be able to retrieve the information once it’s stored.