Human beings have more control over our physiological functioning that is generally believed. Our thoughts and attitudes have a strong effect on the health of our bodies. For example, it is well known that a strong sense of purpose has a powerful positive effect on physical health. The psychologist Viktor Frankl was convinced - based on his experiences in concentration camps during the Second World War - that a strong sense of purpose could keep people alive, and that the loss of purpose could lead to illness and death. Frankl believed that a “loss of hope” could lead to a person "giving up" and allowing themselves to die. So a person’s intention and will can certainly help to determine their survival or death. Frankl was convinced that a “loss of hope” could lead to depression and possibly even to death. There are many cases of people who are seriously ill, in the process of dying, who keep themselves alive in order to experience specific events - such as the marriage of a daughter, a final Christmas or a birthday. Once the event has passed, the person “allows’ themselves to die.
Surprisingly, it is difficult to be precise as to this height limit. While some unlucky ones die of falls in their bathtub, others have survived falls from incredible heights. For example, The Free Fall Research Page lists the case of World War II Russian airman, Lt I M Chisov. Chisov's Ilyushin IL-4 bomber was shot down by German fighters in January, 1942. Chisov fell 22,000 feet (6,705 metres) and hit the edge of a snow-covered ravine and rolled to the bottom. Although badly injured, Chisov survived. Although this is not cliff diving into water, it shows what is possible.