the spirit of giving: genes, behavior, & the nature of altruism are a part of our evolutionary dna
As November’s autumn leaves abandon tree branches, exposing them to winter’s imminent onslaught, the painful vulnerability experienced by low-income individuals and families due to the ongoing recession will be amplified by the pressures of the holiday season. The materialism of the holidays drains even economically comfortable families of both energy and resources. However, for those facing the terrifying concerns of not having a roof over their heads or food on the table, the juxtaposition of joy and celebration with the realities of poverty pushes such families to the pinnacle of suffering.
Yet the holiday season also breeds an emergence of altruism, an opportunity for humanity to rise to the occasion and alleviate the suffering around us with an old-fashioned anodyne: the spirit of giving. Sir Winston Churchill wrote, “We make a living by what we get; we make a life by what we give,” considering a life without altruism to be tantamount to no life at all. Thus, with the holiday season upon us, there is no better time to examine the nature of altruism, a popular quandary for evolutionary biologists as well as behavioral geneticists.
We often talk about the “spirit of giving,” implying that the act of giving originates from the non-physical dimension of ourselves; as though giving essentially derives from the soul. This idea assumes a dichotomy between body and soul, the physical versus the spiritual. This is a variation on Cartesian dualism, an explanation proffered by French philosopher René Descartes in the 1600s that the mind and the brain are distinct entities. We may never be able to confirm or deny the existence of the soul, and human qualities that derive from it, yet thanks to social neuroscientists and behavioral geneticists, science has began to ascribe human qualities such as generosity, kindness, and altruism to our genetic makeup.
The international quest for decoding human physical and behavioral attributes, the Human Genome Project, has come a long way since its humble beginnings in 1990. The first and initially formidable task (completed in 2003) was to identify the estimated 20-25,000 genes responsible for making us uniquely human and deciphering inter-individual variations. It also involved determining the sequence of the four nucleotides—adenine, thymine, cytosine and guanine—of which human DNA is composed.
Our bodies consist of microscopic building blocks called cells, each with a unique structure and function. These individual units comprise the tissues that make up our organs and organ systems, and the macroscopic entirety of our physical selves. Yet the sequencing of the genome, the totality of genetic information that serves as the blueprint for these cells, does not present the greatest challenge to science; rather, it is understanding how different combinations of these genes (which are expressed, or turned on, at different levels and at different times) paired with their interactions in infinite combinations that defines our selves and our individuality.
Yet of course that is not all. As written by Matt Ridley in Genome: The Autobiography of a Species in 23 Chapters, genetics “is a world of grays, of nuances, of qualifiers, of ‘it depends’.” DNA sequence variations from one individual to the next arise due to changes in a single letter of the code, termed single-nucleotide polymorphisms (SNPs). And mutations, or spontaneous and accidental changes in one or multiple nucleotides, have the capacity to completely alter the blueprint’s instructions to the cell it controls.
The initial tasks of relating a single physical trait such as eye color to a specific sequence of DNA’s repetitive code required some audacity, yet the emerging field of behavioral genetics—focusing in on a confined aspect of human behavior and working backwards to isolate the particular combination of genes responsible for it—is far more daunting.
As Joseph McInerney of the U.S. Department of Energy's genomic projects explains, first the behavior in question must be strictly defined, and researchers must establish a means of measuring the behavior “with acceptable degrees of validity and reliability.” Then, since behaviors in their complexity necessitate multiple rather than single genes, scientists must use a multidimensional approach. In addition to analyzing how many genes are involved, they must also integrate analyses of families and populations inheriting these genes in order to distinguish how much variation in a population is attributable to these genes rather than to the environment interacting with them.
With this rudimentary understanding, let us continue to the task of analyzing altruism, defined by Reuter et al. (2011) in Social Cognitive and Affective Neuroscience (SCAN) as “selfless concern for the welfare of others.” Perhaps more importantly, as Jonah Lehrer points out in “Kin and Kind: A Fight About the Genetics of Altruism” (The New Yorker, Mar. 5 2012), altruism may involve helping others “even if it comes at a steep personal cost.”
The evolution of altruism is a conundrum. According to Darwinism and the theory of natural selection, we are products of evolution. We are products of hundreds of thousands of years where selective pressures in our environment allowed only those with the “fittest” genetic makeup, one that promoted survival even in the most trying circumstances, to survive. These survivors would then reproduce, passing those survival—promoting genes onto future generations and weeding out the unfavorable genes.
Since altruism implies a potential personal cost to the giver, as Lehrer writes, “Darwin saw the existence of altruism as a challenge to his theory of natural selection . . . . After all, if life were such a cruel ‘struggle for existence,’ then how could a selfless individual ever live long enough to reproduce? Why would natural selection favor a behavior that made us less likely to survive?”
“And yet,” Lehrer continues, “as Darwin knew, altruism is everywhere, a stubborn anomaly of nature . . . the ubiquity of such behavior suggests that kindness is not a losing life strategy.” This brings us to Darwin’s hypothesis in The Descent of Man, which suggests that human generosity might have evolved as an emergent property not of the individual but of the group. Our ancestors were inarguably social beings who could not have survived without the power of cooperation inherent in tribal or clan social structures. Thus, perhaps generosity ensured that the clan having the most altruistic individuals could outcompete a clan composed of selfish individuals. Lehrer cites E. O. Wilson’s conclusion: “Selfishness beats altruism within groups. Altruistic groups beat selfish groups. Everything else is commentary.”
Now back to the biology. As explained earlier, individualistic diversity emerges from different versions of particular genes. Encrypted in these genes are unique recipes for the incredible diversity of chemicals, peptides, and polypeptides or proteins our cells are capable of producing. These molecules orchestrate a symphony of signaling events that ultimately determine what we are, who we are, and how we are, thanks to the chemical messengers in our brain called neurotransmitters that can dramatically alter our disposition at a moment’s notice.
The notion that we are the pilots of our own selves is far from reality; rather, we are avatars of the information that has been encoded in our DNA since day one of conception. And now researchers are beginning to realize the extent to which the “how” we are—how happy, how sad, how easily anxious or how plucky, and even how empathic or how giving—is directly attributable to our genes, “the real Slim Shady.” As discussed, some scientists hypothesize that giving is rooted in mutualism—the “I help you, you help me” mentality, or mutual reciprocity. But what if the gain from giving is more direct and more tangible than that? Armed with scientific evidence, scientists are beginning to hone in on a more immediate benefit: stimulation of our innate reward pathway, the same one responsible for pleasure and the highs of addiction.
The aforementioned chemical messengers that make us tick also serve as keys that unlock the doors to our brain’s reward center, the mesolimbic pathway. Research has indicated that particular areas of our brain are responsible for motivation and pleasure-seeking behavior. Is it possible that we have been pre-programmed to engage in altruistic behavior by an innate mechanism where giving enables us to experience the same warm and fuzzy feelings associated with food, sex, drugs and money, the “warm glow” effect?
Scientists are finding evidence that this is so. Jorge Moll et al. (PNAS, 2006) used functional magnetic resonance imaging (or fMRI) to decipher which parts of the brain are recruited for empathy, compassion, and charitable behaviors. They examined subjects in hypothetical situations of distributing both costly and non-costly donations, as well as receiving pure monetary rewards.
Interestingly, our brain experiences the act of giving a donation similarly to the way it experiences receiving reward money. Both acts stimulate overlapping areas of our inherent reward system, the ventral tegmental area (VTA)-striatum network, which is largely mediated by dopamine. In the brain, neurotransmitters such as dopamine are released by nerve cells to communicate with other nerve cells in the circuitry of stimulation. Dopamine heavily influences reward anticipation and, according to PNAS (December 24, 2002), modulates the highly-coveted experience of euphoria. As such, dopamine is a principle player in our vulnerability to addiction.
Giving donations also specifically recruits activation of an area of the brain implicated in attachment, trust and cooperation, the subgenual area. This area is rich with dopamine and serotonin. Serotonin, a principle pharmacological target in treating depression and anxiety-related disorders, is a chemical messenger that mediates our sleep and appetite, but also our moods and feeling good in general. When the right chemicals bind to their respective receptors, an explosion of electrical activity erupts, not unlike Rockefeller Center’s Christmas tree lighting ceremony. No wonder that, as Diana Rico writes in Ode Magazine (December 2011), “giving feels so good.”
So yes, giving may have the potential to be addictive. This begs the question, have we possibly been pre-programmed to engage in charity to ensure the survival of our fellow humans? Finally, what are the genetic differences responsible for the disparities between tendencies towards giving? And can those of us less predisposed towards altruism nevertheless develop this area of the brain, like learning to ride a bike or play a musical instrument? Once again, the old nature vs. nurture is called into play.
There’s an abundance of research elucidating novel roles for the previously mentioned single nucleotide polymorphisms. For example, disparities in success to drug treatments have been attributed to having these slightly different versions of the same gene. But now research is beginning to link gene polymorphisms to differences in human behavioral variations as well. In terms of understanding altruism, two separate genes hold the nomination.
A recent study by Knafo et al. (Genes, Brain and Behavior, 2008) has attributed individual differences in altruistic behavior to the arginine vasopressin 1a (AVPR1a) receptor, which has previously been implicated in bonding behaviors in mammals such as the prairie vole (a species whose harsh environment makes cooperation a prerequisite for survival). Importantly, vasopressin is a known intermediate in the dopaminergic pathway. And in experimental settings, individuals having a particular variant of the AVPR1a gene were more likely to be more giving, and more generous in their giving.
Recall the aforementioned SNPs, changes in a single letter of the DNA code. According Reuter et al. (SCAN, 2011), the functional COMT Val158Meth SNP, a genetic variant that encodes for the amino acid valine instead of an alternate amino acid, methionine, heavily influences behaviors such as empathy, cooperativeness, and altruism. This gene happens to encode for receptors of the neuropeptides oxytocin and the previously mentioned vasopressin, and the significance? These neuropeptides play an intimate role in stimulating none other than our old friend, the dopaminergic system. Once again, the reward pathway is the hidden gem.
Finally, regardless of our genetic makeup, can we train ourselves to be more compassionate? Stanford University’s CCARE, the Center for Compassion and Altruism Research and Education, points to empirical evidence that this is the case. Compassion training programs such as Compassion-Focused Therapy (CFT) and Compassionate Mind Training (CMT), derived from Buddhist meditation principles, have successfully trained subjects to experience increased compassion for others. Furthermore, these studies have demonstrated that practicing compassion simultaneously improves mental health and well-being while reducing stress levels, a key means of bolstering our immunity.
Evidence that we are hardwired for empathy, compassion, and altruism is ubiquitous. Perhaps the feel-good or reward response to giving is an atavism that promoted the survival of our species long ago when survival was precarious, given our status as prey to saber tooth tigers, “lions, and tigers and bears, oh my!”
Many begrudge the fact that such scientific evidence merely taints the spirit of generosity by implying that, as Frans B. M. de Waal (“Putting the Altruism Back into Altruism: The Evolution of Empathy”, The Annual Review of Psychology, 2008) puts it, helping another “boil[s] down to helping oneself.” De Waal’s response: “It does,” but “A truly selfish individual would have no trouble walking away from another in need, whereas empathic engagement hooks one into the other’s situation.” He continues, “This is, in fact, the beauty of the empathy-altruism connection: The mechanism works so well because it gives individuals an emotional stake in the welfare of others.”
According to the Dalai Lama, “If you want others to be happy, practice compassion. If you want to be happy, practice compassion.” Thus, for the sake of the holiday season, or in response to the country's collective prolonged unemployment, or for self-improvement purposes, or just for the sake of bettering humanity, let us try to cultivate in ourselves and in others greater kindness and compassion for our compadres.