According to a large-scale study conducted by Duke University, there is a link between attitudes and physical well-being. The reports state that the research team did their best to eliminate external factors, such as mental health issues, vices, and hereditary diseases from the final results. The end result of the report makes the claim that, if two people with similar states of physical well-being are taken, the one with a more positive outlook is more likely to have better health in the long-term. The one that has more fear and anxiety about his physical condition is more likely to suffer from some sort of illness or have poorer overall health than his counterpart.
Of course, before taking this into account, people should also eliminate possible factors affecting longevity and health. For example, people who have depression or Thanatos complex may perform acts that can permanently compromise their immune system, possibly cutting their life expectancy. The relationship between diet and vices to physical and mental health also plays a larger role than outlook and attitude theoretically do. Further study is under way, but Dr. Ellen Idler has studied the research data and the implications extensively. She believes that the link is less of a “mystical” one and more deeply rooted in the principles of cause and effect. According to her theory, the relationship between attitude and longevity is one that is connected to mental health.
In her theory, people who have a more negative outlook are more likely to slip into unhealthy lifestyles. Whether this is subconscious or not would likely vary from case to case, but she believes that negative attitudes tend to eventually lead to negative states of mind. It is known that mental health is connected closely to physical health, with a number of mental disorders either having physical symptoms or side effects. While a negative outlook in life may not necessarily be an act of self-destruction on the person's part, it may help push the person into an increasingly degenerate lifestyle.
Further study is likely to be needed before any concrete connections are made. There are currently two major areas where the studies are liable to concentrate. First is the theory that a positive outlook is linked to mental health and that is how it affects the physical well-being and longevity of a person. Another, far less accepted theory, is that a positive outlook actually can influence the body in the same way that some people manifest physical symptoms simply by believing that they are ill.