<P> Maslow's theory was fully expressed in his 1954 book Motivation and Personality . The hierarchy remains a very popular framework in sociology research, management training and secondary and higher psychology instruction . Maslow's classification hierarchy has been revised over time . As we have discussed, the original hierarchy states that a lower level must be completely satisfied and fulfilled before moving onto a higher pursuit . However, today scholars prefer to think of these levels as continuously overlapping each other . This means that the lower levels may take precedent back over the other levels at any point in time . </P> <P> Maslow's hierarchy of needs is often portrayed in the shape of a pyramid with the largest, most fundamental needs at the bottom and the need for self - actualization and self - transcendence at the top . </P> <P> The most fundamental and basic four layers of the pyramid contain what Maslow called "deficiency needs" or "d - needs": esteem, friendship and love, security, and physical needs . If these "deficiency needs" are not met--with the exception of the most fundamental (physiological) need--there may not be a physical indication, but the individual will feel anxious and tense . Maslow's theory suggests that the most basic level of needs must be met before the individual will strongly desire (or focus motivation upon) the secondary or higher level needs . Maslow also coined the term "metamotivation" to describe the motivation of people who go beyond the scope of the basic needs and strive for constant betterment . </P> <P> The human brain is a complex system and has parallel processes running at the same time, thus many different motivations from various levels of Maslow's hierarchy can occur at the same time . Maslow spoke clearly about these levels and their satisfaction in terms such as "relative", "general", and "primarily". Instead of stating that the individual focuses on a certain need at any given time, Maslow stated that a certain need "dominates" the human organism . Thus Maslow acknowledged the likelihood that the different levels of motivation could occur at any time in the human mind, but he focused on identifying the basic types of motivation and the order in which they would tend to be met . </P>

The base level of maslow's hierarchy of needs pyramid includes