We have all seen it in action in others, as well as in ourselves. It is one of the few things that puzzled the Father of Evolution, Charles Darwin. A worker bee cannot reproduce, and exists only for the good of the hive and the propagation of the queen bee’s genes. A vampire bat will spontaneously share food through regurgitation. A man will help a blind woman cross the street and we, U.S. residents, agree to pay taxes of which a good portion goes to welfare recipients. These all fall into the category of altruism, which is “the unselfish concern for the welfare of others” (1). But is altruism good for the altruistic person? The biological definition of altruism argues that such acts are undertaken to make the altruist feel better, increase the reproductive success of the altruist, or increase the prevalence of genes for altruistic behavior (2). One definition suggests that altruism is mutually beneficial and evolutionary history has seen the success of countless mutually beneficial symbiotic relationships from lichen (algae and fungus) to E. coli in our stomachs (2). Altruism is no different and science is pressed to answer a hard question: why? A growing wave of research is proving the powerful benefit of altruism on both mental and physical well-being, as well as providing plausible explanations for why we observe what we observe, from the age-related benefit of altruism to why altruism exists at all.

Altruism and Health

Getting around the Catch-22

One key issue to keep in mind before delving into the research is  the Catch-22, the age old question of which came first — the chicken or the egg, well-being or altruism. As Synder and Lopez note, usually when you feel good (i.e. healthy and happy), you tend to give and be altruistic (3). What we seek, however, is the reverse effect: that altruistic behaviors directly cause well-being. As we see through subsequent research, the problem is dealt with in several ways by: 1) conducting a longitudinal study that allows the researcher to examine the effects of changing a particular variable over time in response to an experimental treatment and thereby establishing causation; 2) performing an experiment that randomly assigns one group to perform altruistic actions and another group to not, which acts as the control; and 3) controlling for baseline health and other potential confounding variables (extraneous variables that may themselves correlate with the independent or dependent variables) using multivariate regression analysis.


A mother chimpanzee displays “targeted helping” by reaching out to her juvenile son in response to his cries for help.

More recent studies confirm the positive mental benefits of altruistic activities. Dulin and Hill studied the relationships between altruistic activity and positive and negative affect among low-income older adult service providers (5). Positive affect is “the stable disposition to experience positive emotions” and negative affect is the disposition to experience negative emotions (6). Among a sample of 115 low-income older adults who were actively providing services to others within a volunteer service program called Foster Grandparents and Senior Companions, the researchers examined altruistic activity as a predictor of positive and negative affective states. After controlling for relevant demographic variables including social support and income, the researchers found that altruistic activity was a significant predictor of positive affect, but not negative affect. 

In the same year, with an even larger sample size, Schwartz et al. focused on a stratified random sample of 2,016 members of the Presbyterian Church located throughout the U.S., a form of sampling that involves dividing the population into groups with similar characteristics (7). The study investigated whether altruistic social behaviors such as helping others were associated with better mental health. Questionnaires evaluated giving and receiving help, prayer activities, positive and negative religious coping and self-reported mental health. Multivariate regression analysis revealed that after adjusting for variables like age, gender, stressful life events, income, general health, religious coping and asking God for healing, both helping others and receiving help were associated with mental health. In fact, giving help was more significantly associated with better mental health than was receiving help. This study also emphasized that altruism must be reasonable for the giver in order to bring benefits. The authors found that “feeling overwhelmed by others’ demands had a stronger negative relationship with mental health than helping others had a positive one” (7). 

Most up-to-date research has been conducted on older adults, with little information on the young and middle-aged. Further, the scarce research on youth volunteerism is generally limited by a cross sectional design, in which subjects are assessed at a single time in their lives and is efficient at identifying association but does not clarify causal relations. One such study by Johnson et al. did suggest the benefits of volunteering on the young (8). Johnson et al. also studied a representative community sample of both volunteers and nonvolunteers over long periods of time. The study indicated that those adolescents who became involved in volunteer activities had higher future aspirations, higher self-esteem, and a higher intrinsic motivation toward school work. 

Physical health

Not only does altruism have a positive effect on mental health, but it also plays a key role in shaping physical health. Specifically, we will focus our attention on longevity, physical functioning, better health behaviors, and HIV survival. Many studies report that volunteers tend to live significantly longer than those who do not volunteer. Recently, Shmokin et al. studied 1343 individuals ages 75+ in Israel from 1989 to 1997 and found a 33 percent reduction rate in mortality for volunteers compared to nonvolunteers after adjusting for prior health, health behaviors, and social support (9). Though Oman et al. found an inverse correlation between volunteering and mortality (10), Musick et al. interestingly reported contrary evidence suggesting that larger amounts of volunteering (in this case, more than 40 hours per year or for two or more organizations) might produce less benefit than smaller amounts of volunteering (11). This discrepancy in studies may be due to variations of personal ability to manage time and deal with stress, and intrinsic personalities of the individuals when faced with challenges to avoid being overwhelmed by altruism. To confirm these speculations, more research is needed.

Not only do altruists and volunteers tend to live longer, they are also physically healthier.  For instance, after an elderly man named Fred Dekuyper started volunteering at a school, a medically inexplicable event occurred. Thinking back, he recalled, “I used to walk with a cane all the time, and now I don’t need the cane anymore,” (12). Dekuyper is not alone. Many studies have examined relationships between volunteering and physical functioning. Luoh and Herzog found that, compared to nonvolunteers or those volunteering less than 100 hours, those who were volunteering 100 hours or more in 1998 were approximately 30% less likely to experience physical functioning limitations, even after adjusting for demographics, socioeconomic status and baseline functioning limitations (13). A year later, Morrow-Howell et al. examined data collected between 1986 and 1994 from more than 1,500 US adults, finding that volunteering predicted significantly less functional disability three to five years later (14).

One reason that volunteers live longer and are physically healthier may be that volunteers tend to practice better health behaviors. After adjusting for age, Oman et al. found that higher levels of volunteering were significantly related to exercising and refraining from smoking (10). Shmotkin et al. and Harris and Thoresen each found statistically significant associations between volunteering and greater physical activity (15). 

Further, there are many intriguing studies of altruism and the health and survival of HIV positive individuals. Ironson et al. analyzed a group of 79 long-term survivors of AIDS (people who had survived more than twice as long as expected after diagnosed with AIDS) who were compared with 200 people who had HIV with a normal course of the illness (16). Those in the longer survivor group were significantly more likely to have volunteered (mostly helping other people with HIV) than those in the normal course comparison group.  Further, Irsonson followed HIV patients who volunteered, like Katherine Scott, who talked to teenagers about avoiding infection, and Stephen Baker, who counseled fellow HIV survivors. These and other HIV patients who helped others had lower stress levels and higher immune resistance.  In fact, Baker said that he could feel how volunteering improved his health and Scott’s disease-fighting cell count actually went up, from 200 to 800.

Age, Altruism, and Evolution

It is clear that there is a lack of altruism research on youth and middle-aged populations as compared with that on the elderly. Perhaps the middle-aged have lives that are too busy to handle much altruistic activity outside of work without becoming overwhelmed. In support, we have already seen that Schwartz et al. found that feeling overwhelmed by others’ demands has a strong negative relationship with mental health (7). Psychologist Jane Piliavin has another explanation, after observing that the level of benefit from volunteering depends on one’s life stage in complex ways. We have already seen that Johnson et al. produced results showing that volunteerism increased certain aspects of mental health for youth, but these results do not appear to have much effect on the overall well-being of the adolescents involved. For adults, the story is a bit different. Thoits and Hewitt tracked volunteering and well-being over many years in thousands of people and were able to show a causal effect, i.e. when a person increased volunteer work, all measures of well-being increased on average afterwards for as long as the volunteer work lasted (17). The elderly benefit even more than do adults, particularly when their volunteer work either involves direct person-to-person helping, or is done through a religious organization. The benefits of volunteer work for the elderly are so great that they even result in a longer life, as Shmokin et al. have shown. 

This pattern of age-related change in the degree of benefit for the altruistic person suggests that the major benefits of volunteer work are bringing people together, and helping them to construct a meaningful life story (18). Since adolescents are normally already engrossed in a dense network of social relationships, and since they are just beginning to construct their life stories, they do not need these benefits as much, and hence they benefit the least from altruism. With age, however, a person’s story begins to be molded into shape, and altruistic activities provide both depth and virtue to life. In old age, when social networks are diminished by the death of friends and family, the social benefits of volunteering are strongest. In fact, the socially isolated elderly benefit the most from volunteering (19). Furthermore, in old age, generativity (a concern for guiding the next generation) and relationships are much more relevant and matter much more than individual achievement, so any activity that lets one “give something back” fits well into the story and helps to construct a meaningful and satisfying conclusion.

In light of evolutionary psychology, group selection theory suggests a powerfully adaptive connection between widely diffuse altruism within groups and group survival. In support, Lee proposes that a considerable evolutionary selective pressure for altruistic generativity in older adults may help explain that older adults appear to benefit more from altruism (20). Since human beings live and work well past their reproductive years, Lee suggests intergenerational transfer as an explanation, i.e. selective advantage to the young of grandparenting families may explain human longevity well past the stage of reproductive potential. Thus, natural selection may be at work through improved survival rates of grandchildren who are helped by both parents and grandparents. This holds true today in a variety of ethnic groups, including the African American community as studied by Gallop and Jones (21). 

Decoding the Evolutionary Paradox of Altruism 

Altruistic behavior, such as volunteer firefighting, may have mental and physical health benefits.


At the individual fitness level, where the focus of natural selection is primarily based, we have seen earlier in this paper copious evidence of the mental and physical benefits that altruism can potentially bring to the giving individual. These benefits, for a long time unconsidered and left in the shadows, now help us to see clearly the link between evolution and altruism, i.e. how altruism can increase the fitness and thus the reproductive success of an altruistic individual by increasing the likelihood of mental and physical well-being.

As we go up one level from the individual to the family, we arrive at the familiar concept of kin selection, “the evolutionary mechanism that selects for those behaviors that increase the inclusive fitness of the donor [altruistic individual]” (23). The idea is that altruistic behavior boosts the fitness of its relatives with common genes even though it may reduce the individual’s own fitness. The family genes can still be propagated in future generations. 

To explain altruistic behaviors with strangers like volunteering, it is necessary to view the entire human species as one group or one “family.” In this sense, altruism promotes the inclusive fitness of the human species. Further, volunteering and other altruistic behaviors also relate to the individual level of well-being that can be gained from altruistic behavior. Thus, evolution is deeply enmeshed in altruistic behavior.

How Certain Can We Be that Altruism Causes Good Health?

Altruism promotes deeper positive social integration, distraction from self-preoccupation, enhanced meaning and purpose, a more active lifestyle, and the presence of positive emotions such as kindness that displace harmful negative emotional states. Thus, it is entirely possible to assert that altruism enhances mental and physical health. 

It is key to remember that significant findings regarding health in relation to altruism, or in any area of research, are done on a given variable-controlled population. Thus, at best, we can conclude that altruism is one of the factors that increase the odds of maintaining better health or survival. It certainly is no guarantee of good health, and having too much of a good thing, even altruism, can lead to harmful effects as evidenced by the overburdened caretaker. 

If someone is depressed or physically disabled, it is less likely that he or she will engage in helpful behaviors. There may thus be a tendency for the healthy to be altruistic, partially explaining the better health of altruists. In search of a stronger claim that altruism causes better mental or physical health, studies using biological markers have looked at individuals before and after engagement in altruistic behaviors and indicate immune-enhancing biological markers. This may help explain the helper’s high, which is the immediate physiological change that may occur as a result of volunteering and helping others. Research on physiological advantages is limited, but one early study found that those students who watched a film about Mother Teresa’s work with the poor and sick of Calcutta showed significant increases in the protective antibody salivary immunoglobin when compared with those watching a more neutral film (24).

The argument for causality is further strengthened by the inarguable assertion that emotional states of unselfish love and kindness displace negative emotional states like anxiety, hatred and fear, which cause stress-related illness by debilitating immune function (25). In the face of danger, the negative emotional states are important, but oftentimes, the fight-flight response and its corresponding negative emotions stay turned on for a long time even after there is no longer danger. Positive emotions elicited by altruism, thus, can gain dominance over anxiety and fear, turning off the fight-flight response and thus, turning off negation emotions that would have compromised the body’s immune system.

Public Health Significance and the Road Ahead

Altruism has great potential to be a major player in future public health. Currently, public health is rightfully focused on environmental toxins and the control of epidemics (26). However, a positive vision of public health must also nurture helping behavior. Altruism can be prescribed by healthcare professionals and can be even practiced by these very healthcare professionals for their own well-being as well as for others. One example of the therapeutic use of altruism can be found in the Twelve Steps of Alcoholics Anonymous, where Step 12 requires the recovering alcoholic to help other alcoholics. 

The essential conclusion of this article is that a strong direct correlation and high probability of causality exists between the well-being, happiness, health, and longevity of people who are kind and compassionate in their charitable helping activities, so long as they are not overwhelmed. Of course, this is a population generalization that provides no guarantee for the individual. Yet, there is wisdom in the saying, “A generous man will prosper, he who refreshes others will himself be refreshed.” Life can be difficult, and death should not be denied. Love, however, makes the way easier and healthier both for those who give and for those who receive. And evolution is on your side.


1. D. Jost et al., American Heritage Dictionary of the English Language (Houghton Mifflon, Boston, 2006). [fourth edition]
2. N. Barber, Kindness in a Cruel World (Prometheus Books, USA, 2004).
3. C. R. Synder, S. J. Lopez, Positive psychology: The scientific and practical explorations of human strengths (Sage Publications, California, 2007).
4. K. I. Hunter, M. W. Linn, Int. J. Aging Hum. Dev. 12, 205-213 (1980).
5. P. Dulin, R. Hill, Aging & Mental Health 7, 294-299 (2003).
6. C. Peterson, A Primer in Positive Psychology (Oxford Univ. Press, NY, 2006).
7. C. Schwartz, J. B. Meisenhelder, Y. Ma, G. Reed, Psychosomatic Medicine 65, 778-785 (2003).
8. M. K. Johnson, T. Beebe, J. Mortimer, M. Synder, Journal of Research on Adolescence 8, 309-332 (1998).
9. D. Shmotkin, T. Blumstein, B. Modan, Psychology and Aging 18, 602-607 (2003).
10. D. Oman, C. E. Thoresen, K. McMahon, Journal of Health Psychology 4, 301-316 (1999).
11. M. A. Musick, A. R. Herzog, J. S. House, Journals of Gerontology Series B-Psychological Sciences Social Sciences 54, S173-S180 (1999).
12. J. Stossel, S. Johnson, Doing Good and Feeling Better (2007). Available at http://abcnews.go.com/2020/story?id=2685717&page=1.
13. M. C. Luoh, A. R. Herzog, Journal of Health and Social Behavior 43, 490-509 (2002).
14. N. Morrow-Howell, J. Hinterlong, P. A. Rozario, F. Tang, Journals of Gerontology: Psychological Sciences and Social Sciences 58B, S137-S145 (2003).
15. A. H. S. Harris, C. E. Thoresen, Journal of Health Psychology 10, 739-752 (2005).
16. G. Ironson et al., Annals of Behavioral Medicine 24, 34-48 (2002).
17. P. A. Thoits, L. N. Hewitt, Journal of Health and Social Behavior 42, 115-131 (2001).
18. J. Haidt, The Happiness Hypothesis: Finding Modern Truth in Ancient Wisdom (Basic Books, NY, 2006).
19. R. A. Emmons, Personal Goals, Life Meaning, and Virtue (American Psychological Association, Washington DC, 2003).
20. R. D. Lee, Proceedings of the National Academy of Sciences 100, 9637-9642 (2003).
21. G. H. Gallop, T. Jones, Saints Among Us (Morehouse Group, NY, 1992).
22. C. Darwin, On the Origin of Species (1859). Available at http://www.talkorigins.org/faqs/origin/preface.html .
23. N. A. Campbell, Biology (Benjamin-Cummings Pub Co, USA, 1993). [third edition]
24. J. R. Edwards, C. L. Cooper, Social Science and Medicine 27, 1447-1459 (1988).
25. B. L. Fredrickson, American Scientist 91, 330-335 (2003).
26. M. E. McCullough, C. R. Snyder, Journal of Social and Clinical Psychology 19, 1-10 (2000).