Researchers have presented many theories to explain our giving, social, and cooperative behaviors or why we are eager to help our families, friends, and communities. Evolutionarily, we are social primates who have lived communally for over 50 million years.¹ Communal living offers protection and socialization opportunities, which is why natural selection has long favored the psychological mechanisms responsible for cohabitation and cooperation.¹ Recently, the practice of using selfless, kind acts (also known as altruism) to enhance personal well-being has grown in popularity. What motivates us to go above and beyond to help total strangers?
Happiness researchers and behavioral scientists have become increasingly interested in this question. Research groups, charities, and government organizations have also become intrigued by this effective and widely-accessible method of enhancing subjective happiness, decreasing social isolation, and alleviating the burden of more serious mental and physical health conditions.¹
Altruism is placing other people’s needs above our own; this can be as simple as giving up your seat on the subway to someone who needs it more, or as complex as starting a revolutionary non-profit with the potential to save millions of lives. Altruism is kindness in action, and it can vary in both mechanism and motivation.¹
Despite conflict among family members, studies show that we are most likely to be kind and helpful to those in our own biological tribe. In a rigorous meta-analysis of 200 papers studying the evolutionary causes of altruism, researchers concluded that no other biologically-relevant explanation for this exists besides genetic relatedness.²
Parental care is the best example of this form of altruism, one that is also expressed plainly in much of the natural world. In humans, kin altruism most often presents as kindness in the form of love, care, sympathy, and compassion for the members of our immediate and extended families.¹
Because natural selection favors cooperation and collaboration, we also readily express kindness and compassion to members of our non-biological communities. We are kind to others with whom we share a common interest, including strangers. This innate drive for collaboration is why we form clubs, gangs, clans, sects, and even nations. We then willingly act in the interest of our chosen community, even occasionally at the expense of others. Mutualism is kindness expressed through loyalty, solidarity, camaraderie, civic-mindedness, community spirit, and commitment to a common cause.¹
Typically, we are kind to people who may return the favor or who we might meet again later. Rarely observed in non-human species, reciprocal altruism results from a set of specific psychological mechanisms:¹
Reciprocal altruism is kindness expressed as sympathy, trust, returning favors, gratitude, forgiveness, and friendship.¹
Natural selection also favors acts of service that help us impress our peers or attract a mate.¹ This competitive form of altruism means we often act kinder or more generous when we think it will enhance our status, especially in the presence of a known rival or potential lover. The most common manifestations of competitive altruism are generosity, bravery, heroism, chivalry, kindness, and public service.¹
Behavioral psychology has continued to find evidence that acts of kindness, compassion, and love offer health benefits to recipients, even though no clear biological reason for altruistic behavior has been established. The positive emotions associated with altruistic acts — especially those that require only a marginal personal cost — have been linked to improved well-being, longevity, better creative problem-solving, professional success, and healthier romantic relationships.³ ⁴
For millennia, Jewish, Hindu, Buddhist, Islamic, and Native American spiritual traditions have highlighted the joys of a life lived in tune with the evolutionary benefits of altruism. Only more recently have psychology and philosophy come together to promote the health-enhancing effects of kindness and generosity for all.³
Displays of altruism may reduce stress and prevent the acceleration of aging at the cellular level, contributing to better health and longevity outcomes.³ The following are some broad examples of altruistic, stress-reducing behaviors:³
In a study of over 2,000 members of the Presbyterian Church living throughout the U.S., researchers found that helping others, as opposed to receiving help, led to an increase in mental well-being.⁵
Following adjustments for factors that might influence results, such as age, gender, and income, researchers found that participants who regularly offered help to others had better mental health. Those who regularly helped others experienced lower levels of anxiety and depression than those who regularly received help.⁵ It’s important to mention that organized religion often promotes a communal environment, which could have influenced this study's results.
In another instance, researcher Elizabeth Midlarsky published the results of two field studies about the relationship between helping others and coping with stress, specifically older adults or siblings of those with disabilities. She ultimately found that helping others is an effective coping strategy for those dealing with difficult situations or emotions.⁶
The reasons for this, Midlarsky notes, could be due to the act distracting the actor, increasing social interaction, or providing an improved sense of meaning to the person’s life. But, whatever the cause of the benefits, there was a marked improvement in the subjects’ perception of independence and competence, as well as a better mood and a more physically active lifestyle.³ ⁶
In a somewhat famous study started in the 1950s, researchers sought to uncover a link between participants’ relationships with their parents (kin altruism) and long-term health outcomes.⁷ From the Harvard classes of 1952 and 1954, the organizers selected 126 healthy young men and provided them with questionnaires regarding their relationships with their parents. The results after thirty-five years are as follows:
As the study concludes, parental love and care, a form of kin altruism, may significantly impact a child’s future physical health, even well into adulthood.⁷ This result could be due to a more secure attachment between caregivers and their children, which has been shown to improve psychological and physical outcomes.¹⁴
In a separate study completed by the University of Miami in 2002, researchers explored how the long-term health outcomes of individuals living with AIDS were affected by different factors, such as spirituality or their level of compassion for others.⁸
Increases in all variables studied showed improved longevity and contributed to higher levels of hope, better health behaviors, more acts of assistance, and lower distress and cortisol levels.⁸ Researchers also found that judgmental attitudes had a significant negative impact on long survival.⁸
Ultimately, both of these unique studies support the notion that a stronger sense of humanity, community, and kindness can significantly contribute to physical health and longevity.
Despite assumptions that humans are driven primarily by self-interest, many people regularly perform selfless actions, such as helping their neighbors or donating blood. There are countless ways people can and do display altruism in their daily lives, including the examples detailed below.
Even in early childhood, research shows children exhibit more happiness when giving than receiving. In one study, 23 two-year-old toddlers interacted with a toy and a puppet. The study included two different scenarios:⁴
Upon observation, researchers noted that the children who attempted to share the toy with the puppet displayed greater happiness than those who interacted with the toy and the puppet separately.
In other testing phases, researchers checked if the puppet’s level of enthusiasm affected the children’s responses. Ultimately, they determined no correlation existed between the puppet’s reaction and the children’s happiness.⁴ Researchers concluded that from a very young age, humans have an inclination toward helpful social behavior and find it “self-rewarding.”⁴
According to the Mayo Clinic, participation in regular volunteering not only keeps you moving and thinking, but it can also do the following:⁹
These benefits can reduce the risk of physical health problems, such as heart disease, stroke, depression, and anxiety.
Volunteering can also give you a sense of purpose, especially if you’re working with a population or organization that has a special significance to you. After spending some time in the service of others, many volunteers report increased feelings of gratitude and appreciation. Donating a portion of your time to a good cause is also a great way to increase social interaction, expand your social and support networks, and spend time alongside people with common interests.⁹
We put together a list of the top 10 health benefits of volunteering to learn more about what helping others can do for you, along with some ideas on how to get started.
Acts of kindness can increase happiness and enhance life satisfaction, no matter how small. In one study, researchers instructed a group of students to perform five acts of kindness per week over six weeks. The acts could be completed all in one day or spread throughout the week.¹⁰ The only other rule about the actions performed was that they should benefit others at a small cost to the students. Some of the acts suggested in the study included visiting an elderly relative or sending a thank-you note to a former professor.¹⁰
After six weeks, members of the control group reported a decrease in happiness, while the acting participants reported a significant increase in overall well-being. This increase, however, was only noted among those who completed all their kind acts in a single day. Researchers concluded that spreading small acts of kindness too far could diminish their positive influence, as they might blend in with habitually kind behavior.¹⁰
In the evolutionary theory of altruism, all altruistic behavior is attributed to preferential treatment of kin or, in some cases, the expectation of later reciprocity. But this theory can’t account for the numerous emotional rewards that come with being of service to others. Some organizations or programs even utilize these emotional benefits to assist clients better. An example of this can be found in Alcoholics Anonymous (AA), whose principal text includes helping other members in the program.¹¹
An act of service differs slightly from an act of kindness — it’s about lessening a burden for someone else without getting something in return. To be of service, you don’t need to provide the same intense, ongoing emotional support as is shared between members of AA; there are plenty of ways to be kind and help others that require minimal effort on the part of the actor, such as the following:
There are four main types of altruism: kin altruism (displaying biological preferences), mutualism (sharing within one’s community), reciprocal altruism (giving and receiving favors), and competitive altruism (public displays of heroism or bravery).
At its core, though, altruism is simply the act of placing the needs of others above our own. Through giving and volunteering, we can also foster a stronger sense of humanity, community, and empathy, which can significantly contribute to our sense of overall well-being.
In the past few decades, behavioral psychologists have found that not only the recipients of kindness, compassion, and love experience health benefits, but the actors involved in these exchanges do as well. The benefits you can receive from performing selfless acts include:¹²
 Curry, O. S., Rowland, L. A., & Van Lissa, C. J. (2018, March 21). Happy to help? A systematic review and meta-analysis of the effects of performing acts of kindness on the well-being of the actor. Journal of Experimental Social Psychology, 76, 320-329. Retrieved February 6, 2023, from https://www.sciencedirect.com/science/article/pii/S002210311730345.
 Kay, T., Keller, L., & Lehmann, L. (2020, November 2). The evolution of altruism and the serial rediscovery of the role of relatedness. PNAS, Biological Sciences. Retrieved February 6, 2023, from https://www.pnas.org/doi/10.1073/pnas.2013596117.
 Post, S. G. (2005). Altruism, happiness, and health: It’s good to be good. International Journal of Behavioral Medicine, 12(2), 66-77. Retrieved February 6, 2023, from https://greatergood.berkeley.edu/images/uploads/Post-AltruismHappinessHealth.pdf.
 Aknin, L., Hamlin, J., & Dunn, E. (2012, June 14). Giving leads to happiness in young children. Public Library of Science - PLOS ONE. Retrieved February 7, 2023, from https://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0039211.
 Schwartz, C., Meisenhelder, J. B., Ma, Y., & Reed, G. (2003, September). Altruistic social interest behaviors are associated with better mental health. Psychosomatic Medicine, 65(5), 778-785. Retrieved February 7, 2023, from https://pubmed.ncbi.nlm.nih.gov/14508020/.
 Midlarsky, E. (1991, January). Helping as coping. Prosocial behavior, 238-264. Sage Publications, Inc. Retrieved February 16, 2023, from https://www.researchgate.net/publication/234039973_Helping_as_coping.
 Russek, L. G., & Schwartz, G. E. (1997, March). Perceptions of parental caring predict health status in midlife: A 35-year follow-up of the Harvard Mastery of Stress Study. Psychosomatic Medicine, 59(2), 144-149. Retrieved February 7, 2023, from https://journals.lww.com/psychosomaticmedicine/Abstract/1997/03000/Perceptions_of_Parental_Caring_Predict_Health.5.aspx.
 Ironson, G, Solomon, G., Balbin, E., O’Cleirigh, C., George, A., Kumar, M., Larson, D., & Woods, T. (2002). The ironson-woods spirituality/religiousness index is associated with long survival, health behaviors, less distress, and low cortisol in people with HIV/AIDS. Annals of Behavioral Medicine, 24(1), 34-48. Retrieved February 7, 2023, from https://academic.oup.com/abm/article/24/1/34/4631542?login=false.
 Thoreson, A. (2021, September 16). Helping people, changing lives: 3 health benefits of volunteering. Mayo Clinic Health System. Retrieved February 7, 2023, from https://www.mayoclinichealthsystem.org/hometown-health/speaking-of-health/3-health-benefits-of-volunteering.
 Lyubomirsky, S., Sheldon, K. M., & Schkade, D. (2005, June). Pursuing happiness: The Architecture of Sustainable Change. Review of General Psychology, 9(2). Retrieved February 8, 2023, from https://journals.sagepub.com/doi/10.1037/1089-2622.214.171.124.
 Alcoholics Anonymous. (n.d.). Step 12. Alcoholics Anonymous. Retrieved February 8, 2023, from https://www.aa.org/sites/default/files/2021-11/en_step12.pdf.
 Fredrickson, B., Cohn, M., Coffey, K., Pek, J., & Finkel, S. (2008, November). Open hearts build lives: Positive emotions, induced through loving-kindness meditation, build consequential personal resources. Journal of Personality and Social Psychology, 95(5), 1045-1062. Retrieved February 10, 2023, from https://psycnet.apa.org/doiLanding?doi=10.1037%2Fa0013262.
 Watson, S. (2021, July 20). Oxytocin: The love hormone. Harvard Health Publishing. Retrieved February 16, 2023, from https://www.health.harvard.edu/mind-and-mood/oxytocin-the-love-hormone.
 Armstrong, K., Fraser, J., Dadds, M., & Morris, J. (2000). Promoting secure attachment, maternal mood and child health in a vulnerable population: A randomized controlled trial. Journal of Paediatrics and Child Health, 36, 555-562. Retrieved February 27, 2023, from https://pubmed.ncbi.nlm.nih.gov/11115031/.