Factors affecting human life expectancy include education, disposable income, acquired medical conditions, psychological resilience, genetics and cultural practices, according to Harvard's T.H. Chan School of Public Health, the University of Colorado and the U.S. National Library of Medicine. Factors such as genetics exert a stronger influence on human life expectancy with advancing age.
Education has a positive influence on life expectancy because it provides knowledge on healthy living habits, according to the University of Colorado. Disposable income also influences life expectancy positively by enabling access to better shelter, food and medical care. Psychological factors are important as well, as psychological resilience can help people cope with morbidity and disability, according to the National Library of Medicine.
Medical conditions such as high blood pressure, elevated blood glucose and obesity affect human life expectancy, according to the Harvard T.H. Chan School of Public Health. These factors cause chronic diseases such as cancer and diabetes, which can lead to death. Ethnicity and geographical location also play a role. For example, Asian Americans have a low body mass index and are less likely to suffer from life-shortening obesity compared to other ethnicities with higher body mass indexes such as Native Americans. Certain geographical areas may encourage life-shortening cultural practices such as smoking.
Approximately 25 percent of the variation among human lifespans is due to genetic differences, according to the National Library of Medicine. The influence of genetics increases once individuals reach age 60.