In physics, the path of least resistance is always taken by objects moving through a system. For example, water flowing downhill follows the path of least resistance as it is pulled downward by gravity.”
The development in meditation seems to follow this rule. Once the mind is sufficiently accustomed to resting at the point of least effort, it will continue to dwell there regardless of the outer conditions. The amount movement needed to regain that position, if it is momentarily lost, becomes smaller.