Continuums

Personality theories define personality as temperament influenced by biological and environmental factors. Temperament is an early predictor of personality as temperament is a more stable characteristic within a person. However, temperament is difficult to measure because people can experience more than one emotion at a time, or have "mixed feelings" (Gnepp, McKee, & Domanic, 1987). As children develop, they are aware that they can feel more than one emotion and that a "lingering emotion" can affect a person's behavior for some time in the future. Lingering emotions can influence long-term a person's personality, intelligence, biological predisposition, economic level, and general attitude toward life's hardships.
Lingering emotions also define personality in the sense that more than one person can experience an emotion. When another person is feeling a similar emotion, that "sameness" (or copying)is not as easy to measure as common characteristics such as biological traits within a person. Biological traits can often be seen within cultures as defined by similar eye color, hair color, skin color, and body structure. As a person matures, you would also take into consideration that at any point a person may be experiencing many feelings not just through their environment but also through their biological senses. It is difficult to not be confused by the many emotions being experienced by just one person much less distinguish what your true personality characteristics are from another individual's defined personality style.
In attempting to distinguish personality or a person within some type of framework and to better define differing emotions and levels being experienced by others around, a matrix or continuum of emotions is necessary. In order to distinguish simply emotions, an indication of how emotions would affect future reactions within a specific environment (biological reactions), it is also important to distinguish lingering emotions and the combination of both in influencing general mood within a culture or context (even within an individual).
Because in distinguising yourself from others, only the strongest waves of mood or feeling will affect others and their reactions to you and your environment, it is important to differ biological reactions (which are so difficult to distinguish because they may be experienced as copying), from other reactions and lingering emotions within a specific context or time. Like a wave, regressed emotions become a cycle that is difficult to bend or change.
* A side note: If you have further questions about temperament, I recommend reading more from Chess and Thomas, whom happened to have researched temperament quite extensively.