At birth, a person is flexible and flowing.
At death, a person becomes rigid and blocked.
Consider the lives of plants and trees: during their time of greatest growth, they are relatively tender and pliant. But when they are fully grown up or begin to die, they become tough and brittle.
The tree which has grown up and become rigid is cut into lumber.
The rigid group leader may be able to lead repetitious and structures exercises but can't cope with lively group process.
Whatever is flexible and flowing will tend to grow. Whatever is rigid and blocked will atrophy and die.