Competency scores indicate potential for behavior, or how likely someone is to perform certain behavior. Higher scores indicate that the associated behavior of the competency is easier for a person, it is something that they tend to do anyway and it takes them less energy to do, meaning they can perform the behavior even under more difficult circumstances.
The potential for behavior, and thus the competency score, is based on Personality and General Mental Ability. These are measured with MAP and Matrigma. The MAP and Matrigma scales are associated in different ways to the four performance areas and their competencies. This relationship defines the way competencies, and ultimately lenses, are scored. As you can see in the picture below, specific personality facets and GMA weigh differently in each competency score. This is because for some competency behavior a personality facet may be very important, but for others much less so, or not at all.