Many years ago when I was still an undergraduate student at a Cambridge University in England, I had a good friend who was doing medical research on cancer. He was trying to find out what, if any, psychological factors would be relevant to a person developing cancer. He developed a very elaborate psychological evaluation, looking for overwhelmingly negative events which could provoke a “death wish” in the subconscious of the patient. But he only found such an event in about forty percent of his subjects. The death of a child, bankruptcy, the end of a marriage, were all potentially contributing factors for the subject developing cancerous cells in less than a year later.
So what about the other sixty percent? For a long time he was baffled. But then he changed the questionnaire from looking for overwhelmingly negative events to overwhelming events of any kind. He included his scope to include positive things: a new relationship, the birth of a baby, a promotion at work. Once he broadened his parameters to look for change of any kind, whether positive or negative, he found a correlation of almost ninety percent.