Responsibility for others is one of the chief causes of tension in executives. To prove this idea, an experiment was conducted some time ago with two monkeys. Scientists devised a method of giving one of the monkeys "executive" training under carefully controlled laboratory conditions.
The monkey chosen for executive training was strapped in a chair with his feet on a plate capable of giving him a minor electric shock. Then they put a light over the desk and turned the light on 20 seconds before each shock. A lever was placed by the monkey's chair. If he pulled the lever after the light came on, the light would go out and there would be no shock. The executive monkey learned to avoid the shock very quickly. The scientists then placed another monkey across the room with the same setup, except that the second monkey's lever didn't work. However, the monkeys soon learned that the first monkey's lever would work for both, turning off the second monkey's light and protecting him from shock as well. This made the first monkey an executive, since he was now responsible for preventing shock for the second one.
The first monkey was intelligent. He quickly took over, protecting both himself and his colleague from shock, responding to both lights or either light without difficulty. There was no outward change in either monkey as the experiment continued, but after awhile the executive monkey, responding to the stress of responsibility for another, developed stomach ulcers. The second monkey's health remained unchanged.