Human laziness has both spiritual and biological causes.
The spiritual cause is the distant memory of when we all were one in the blissful, unmanifested mass consciousness of the universe. The biological cause is the tendency to seize upon opportunities for rest whenever they present themselves. For most of human history, this was absolutely necessary for survival because the universe was a stressful, hostile place. Nevertheless, it is useful to understand how laziness manifests. For if you recognize such patterns of spiritual laziness in others, you can save time by speeding up the decision to discontinue relationships that no longer serve you.