There are many articles, books, blogs, videos, etc. about Jungian personality traits of introversion and extroversion. Here's my summary: Introversion is a inward movement of energy (contractive). Extroversion is an outward movement of energy (projective). There are different reasons for the direction of flow. However, I can only use myself as an example, as I could not find examples of Jungian personality traits being discussed as energy flows. As much as I can understand myself (not enough), below are some possible reasons of the inward flow of personal energy: 1) Low energy level: When I am tired, either lack of sleep, or body requires extra energy to rebuild, realign, recover, etc., then I pull in my energy. 2) Creative work: When I write, I draw in a lot of energy, because otherwise I am a scatterbrain whose ideas don't flow logically or structurally. Other individual activities such as reading also draw in a lot of energy, but it differs in the sense that