Over the last two decades, behavioral and social science research has found mounting evidence that behavioral, social and biological factors affect the human mortality rate. Scientists hypothesized, as one of the many premises, that people's concept of good and evil directly affect a human's life span. Hypotheses testing based on such theories indicates that the predictions had a high probability of being realized.

This conclusion was based on research, performed between 1976 and 1994, under a longitudinal community-based study by L.F. Berkman and S. Leonard Syme. Grants to the Yale School of Medicine and the John Hopkins University School of Hygiene and Public Health from the National Institute of Mental Health and National Center for Health Services Research supported this research. The population data utilized in this study came from information collected by the California State Department of Health of Alameda County residents in 1965. Initially, out of 8,023 questionnaires, 6,928 were returned. However, the follow-up studies included only 2,229 men and 2,496 women between the ages of 30-69. The premises for this nine-year age-related follow-up study of Alameda county residents included that marriage, contact with close friends and relatives, church membership and informal and formal group association affects the mortality of humans. The findings from this research show that the life span of those most isolated and disconnected, with antisocial, uncommunicative and eccentric behavior is shorter than those who have close and lasting social ties. Although church attendance was considered an important factor in the mortality findings, satisfactory marriage ties and social relations with relatives and friends were stronger predictors.

The simplified title for the research study is: "How social relationships influence human death rate." Research results strongly suggest that healthy social relationships affect the life span positively. In fact, those who show humanitarian tendencies, help others, and are easy to get along with and live a harmonious life, will extend their life beyond those whose behavioral attributes are the opposite. Surprisingly, it was also found that the life span of men is shortened to a greater extent than that of women when no social relationships exist. It is astounding that those who are wicked, nasty, spiteful and selfish, as well as those who benefit themselves at the expense of others, and are difficult to get along with, are found to die at a much younger age than those with healthy social behavior. These findings also provide evidence that being of a different race or income, and being involved in physical activities and living a different lifestyle will not have a notable effect on the life span.

This research showed that given the many different social relationships, marriage impacts life span the most. In fact, those who died under the age of 60, the marriage status played a vital role in their earlier demise. The University of Michigan conducted a research study on a population of 165 older people aged 55 and over who were hospitalized for chronic diseases. Not surprisingly, the findings showed that those who were married or lived with family members were in better health and required less hospitalization than those who lived alone.

The University of Michigan and Harvard also conducted mortality-related research. In a study conducted by Harvard's School of Medicine, participants watched a documentary film about a western woman who lived in Calcutta, India. She was a humanitarian who cared for the poor and the disabled in Calcutta's slums. Many were deeply moved by her compassion. The research parameters called for the saliva of the participants to be collected and analyzed immediately when the movie had ended. Analysis of the samples from before and after the movie was compared. It was found that immunoglobulin A, a natural defense that protects humans from any bacteria and viruses, increased considerably after watching the film. Immunoglobulin A, a type of antibody molecule, prevents infection of the respiratory system. Also, medical research indicates that the human immune system is greatly affected by aging; that is, it will become less efficient. As seen above, the immune system can be stimulated by positive social behavior. Thus, the conclusion can be drawn from the above study that those who are compassionate and tolerant towards others can extend their life naturally.

Research has proven that people who are virtuous, noble, morally upright and honest will live a longer life. Thus, psychological factors play an important role in longevity. When a person cheerfully and willingly helps others, he will receive positive feedback from the recipients of his affections. People will be friendly and grateful in return and he will thus receive tender warmth from others. It will help him relax and decrease the stress in his daily life. And, as discussed above, it will benefit the human immune system.

On the other hand, it seems those who harbor ill intent, benefit only themselves at the expense of others, and are difficult to get along with, are found to live a shorter life. For example, it was demonstrated during a number of immunology and aging studies that for people who are aggressive, unfriendly and argumentative, and who show an antagonistic attitude, immune system diseases, such as the cardio-arterial blockage, will worsen. Such a person will suffer from immune system related illnesses more frequently than those with positive social behavior. Those who have a tendency to lose their temper, be angry all the time and always feel hostility towards people will find that it affects their blood pressure. Regrettably, it will lead to various high blood pressure diseases, which are very difficult to cure. Those who committed serious white-collar crimes, such as embezzlement, were found to frequently suffer from insomnia, were easily agitated, nervous and tense. It is known that such psychological factors are the outcome of a guilty conscience. Unsurprisingly, all of them are found to live a shorter life than people who do not commit such crimes.