Human Morality — A Product of Evolution, Culture, or Religion?

I originally wrote this essay as an assignment for an evolutionary psychology course I had taken at Portland State over 8 years ago (March 11th, 2011 to be precise). I had dug it out of the digital rubbish bin of an old blog I was using to publicly post essays I thought this one deserved a second go. Although there were some parts that were fairly cringy to read, there were several things I wanted to update as my thinking as evolved over the years so to speak. I’ve updated some of the arguments and made it some what more coherent and confident.

“I am not advocating a morality based on evolution. I am saying how things have evolved. I am not saying how we humans morally ought to behave.”
– Richard Dawkins

   The question of the origins of moral behavior has been a philosophical topic of debate for thousands of years. It isn’t until the last couple centuries that humanity has been able to make an attempt at explaining morality through the scientific lens of biology and psychology. The question I am going to attempt to answer in this essay is where do we as humans get our ideas of what is morally acceptable and unacceptable, and how has our sense of morality has evolved? I will argue that moral behavior is fundamentally a result of an evolutionary process, of biological origins with cultural and religious memes supporting (or distorting) human morality. The characteristic of morality is fundamentally innate in almost all humans, with the exception of those with serious mental disorders. There is evidence supporting the possibility that it is genetically encoded into our DNA through social and environmental adaptations as the result of thousands of years of repeated behavior. I will present evidence that moral behavior is observable in animal species as well, signifying that it may not be just a human trait. I will also address the purpose as well as the somewhat obvious advantages to moral behavior, especially that of altruism.

   Religious fundamentalists have argued that moral values are divine commandments given to us from god, while others have said that they are the products of our ability to rationally reflect on objective truths about the universe. Yet, others have claimed that moral values are a product of human nature, and further, argue that moral values are merely social conventions or local cultural norms. I argue that all of these explanations play some role in the development of human morality, but also that moral values are primarily not just embedded into human nature, but a product of nature and biology in general. Darwin proposed the moral sense as an inevitable outcome of four elements: social instinct, memory, language and habit.

A Moral Gene

   A critical question that must be asked is whether or not we have a genetic disposition to behave in a morally acceptable fashion. Steven Pinker, an evolutionary psychologist at Harvard University, published an article in the New York Times regarding the possibility of a moral gene. Pinker claims that there is circumstantial evidence that genes for morality exist, although no one has identified them (2008). Investigating further to see if any of the literature had been updated, I found a study conducted in 2011 that shows that serotonin transporter (5-HTTLPR) genotype predicted responses to moral dilemmas (Marsh et al., 2011).

   This claim can be backed up by observing other character traits such as conscientiousness and agreeableness. These character traits are far more correlated in identical twins separated at birth (who share their genes but not their environment) than in adoptive siblings raised together (who share their environment but not their genes) (Jang et al., 2001). If we make the connection between traits such as conscientiousness and agreeability with moral values, then we may have evidence supporting the existence of a moral gene.

   Also, people diagnosed with antisocial personality disorder (or psychopathy), are thought to have these disorders arise from a genetic predisposition (Lykken, 1995). People with these disorders show signs of morality blindness from the time they are children. These signs of moral blindness include torturing animals, bullying younger children, habitually lying, and seem incapable of empathy or remorse for their immoral actions, even though they have normal family backgrounds. If genetics can influence ones moral sensibility, then it is supportive to the claim that moral behavior has a genetic component.


   When we view morality from both an evolutionary-psychological and biological perspective, we can draw inferences as to the origins of morality and the biological advantages of such behavior. Lets observe altruism, a fundamental component of morality. There is a vast variety of evolutionary explanations and advantages, such as reciprocation and kin selection. When explaining altruism from these perspectives, it is functionally defined as a behavior by an individual that increases the fitness of another individual while decreasing the fitness of the actor (Bell, 2008). Meaning the altruist increases the fitness and well-being of another individual while decreasing its own fitness and well-being. This behavior may seem to conflict with the theory of natural selection and survival of the fittest, however social-biologists and psychologists have examined this behavior and have concluded that it benefits the overall well-being of one’s social group.

   When examining the hypothetical situation in which a man jumps into a river to save a drowning child, we must ask what forces are at work. Does this man save the child out of an overwhelming impulse that it is “the right thing to do”? Perhaps “the right thing to do” is really backed by some sort of unconscious reasoning that he couldn’t possibly live with the guilt of allowing a child to drown when he had the power to save its life. It could be another possibility that the man is compelled to save the child out of the threat of possible punishment from his group (or society) for not attempting to do so. Perhaps the man’s action can be attributed to something instinctive or a combination of all of these influences.

   If one has an idea of how the evolutionary process works, they can speculate as to why certain moral behaviors are beneficial. Altruistic behavior, for example, has a variety of possible explanations. One may feel the need to save a drowning child out of possible future reciprocation, fear of punishment for not doing so when they were entirely capable, or because one was raised in a culture to act in situations like this.

Culturally transmitted practices

   Samuel Bowles, a social psychologist and economist at the University of Massachusetts, argues that moral practices presuppose advanced cognitive and linguistic capacities. This may possibly account for the distinctive form of altruism found in other species (2006). His estimates have shown that genetic differences between early human groups are likely to have been great enough so that lethal intergroup competition could account for the evolution of altruism. He says that, crucial to this process, there were distinctive human practices such as sharing of food beyond the immediate family, monogamy, and other forms of reproductive leveling.

   Bowles presents detailed information about how altruistic behavior within groups increases the overall fitness of the group, even though fitness decreases at the individuals expense. In his analysis he also provides an intricate mathematical framework that explains how altruism becomes a dominant trait, and mentions how altruists are more likely to interact with other altruists. Bowles further goes into explaining that intergroup competition could influence the evolution of these culturally transmitted behaviors, and how large metapopulations of individuals living in subgroups benefit.

   To elaborate on this further, I also argue that altruistic behavior, specifically that of altruism towards a stranger, encourages cooperation not just within groups, but also cooperation between external groups. One of the traits that make us humans unique and stronger compared to that of other species of homo sapien (ie homo neanderthalensis) is the fact that we can cooperate in large groups in the hundreds. For example, if I save a drowning child that’s a member of a rival group, it’s possible me and my group might fall into favor with that rival group.

Altruism in Animals

   Morality, also, is not an entirely inherent human characteristic, and it seems that not much thought is given to the social conduct of other species in the context of moral behavior in contrast to that of humans. Conceptualizing morality as a form of behavior opens the possibility of observing it in other species. I will posit that both humans and other animal species share a very similar sense of moral guidelines, however, it is important to note and recognize that morality from a human perspective is significantly more complex as our morals are expanded on by culture, religion, politics, personal values, etc. It is also a more complicated thing because we are more more social creatures. Social interactions with one another are far more complex as well (i.e. we use sophisticated verbal language).

   It has been observed that animals help those individuals to whom they are closely related to and explained by what’s called ‘kin selection’. Kin selection refers to strategies in evolution that favor the reproductive success of an organism’s relatives, even at times at a cost to their own survival. Even though it is not considered true altruism, they do put the well-being of those they are related to above themselves — sacrificing their fitness (or in some cases their own life) in order to increase the fitness of kin. One would think that this is an exception and counterproductive to the successful continuation of an organism’s genes, but seeing as how kin share genetic makeup with the altruist, continuation of the altruist’s genes will continue as long as the kin continues to survive and reproduce.

   Though this is a well documented behavior, I found an example of this phenomenon in a article by the BBC. A bonobo would opt to share his food with his fellow bonobo. Food would be placed in a room which could be easily viewed by another bonobo who was locked out (who I will call ‘bonobo A’ for the sake of avoiding confusion). When the other bonobo (‘B’) entered this room and began helping himself to the fruit, he would within a few seconds unlock the door by removing a wooden peg so that the other bonobo could enter and share the highly desired food. It is speculated that this behavior could be purely altruistic, or more selfish motives could drive this behavior. Specifically, because sharing could be exchanged for future favors. This possible exchange in the future is called reciprocal altruism, which I will get into later.

   Steven Pinker also mentioned in his article referenced above that the impulse to avoid inflicting harm on others can also be found in rhesus monkeys. The monkeys would rather go hungry then to pull a chain that delivered food to them but would simultaneously shock another monkey. The evidence of moral behavior in animal groups supports the indication that morality is not just a human characteristic. If it is not an innate human characteristic and observed in other species, it further hints to a biological process driving morality.

   A final example I want to outline is one that I recently read in Yuval Noah Harrari’s book Homo Deus: A Brief History of Tomorrow. He refers to a study conducted in 2010 where a rat was locked in a tiny cage, then placed that cage within a much larger cell and allowed another rat to roam. The caged rat gave out distress signals, which caused the free rat to also exhibit signs of of anxiety and stress. In most cases, the free rat proceed to help the caged rat, and after several attempts, succeeded in open the the cage and freeing the other imprisoned rat. This study was conducted again but with a piece of chocolate also in the larger cell. Many rats preferred to first free their trapped companion and then share the chocolate. Perhaps the free rat acted out of altruism, or perhaps it acted simply to stop the annoying distress signals.

Mechanisms for Morality

   There are several proposed mechanisms for altruism. Reciprocal altruism, for example, is a behavior whereby an organism acts in a manner that temporarily reduces its fitness while increasing that of another, but with the expectation that the other organism will reciprocate and act in a similar manner at a later time during interaction. The bonobo example above explains how a possible motive for the bonobo unlocking the door for the other is that it might expect a comparable favor in the future. This could also be identified as a motive in the caged rat example.

   Direct reciprocity is especially likely to occur when there is a chance of repeated encounters between two individuals. An example of this out of daily life can be made when observing the relationships one has with coworkers verses a complete stranger. You are much more likely to do a favor for a coworker than for someone you have never met. The chances of doing a favor for the stranger is not nearly as likely for obvious reasons — there is a much higher probability that you will never see the stranger again versus seeing your coworker again, thus there is little probability that the stranger will reciprocate the favor. However, say that you see this stranger regularly on your morning commute, the chances are higher that if asked for a small favor, you may abide. This is supported by the psychological concept that familiarity breeds fondness.

   Socialization plays an important role in shaping moral guidelines as well, but there have been studies showing that infants as young as 18 months show altruistic behavior. Evidence was presented in a CBC article by a psychologist at the Max Planck Institute for Evolutionary Anthropology that infants would attempt to retrieve a peg. The researchers claimed that the infant had observed the adult performing a task with the peg and when the infant believed that the peg was dropped unintentionally, they were much more likely to retrieve the peg than if it appeared that the adult dropped it intentionally.


   I’ve given many examples about the evolutionary origins of altruism, but I’d like to shift to to moral cultural norms, such as taboos. The act of incest has been identified as taboo by literally all cultures and considered a highly immoral act. What would be the evolutionary advantage of perceiving this as unethical? Considering that inbreeding leads to a higher probability of congenital birth defects, there is no question as to why it is considered a taboo. Natural selection has There is no advantage to inbreeding. In fact, there is a major disadvantage.

   This isn’t to say that all taboos have an evolutionary origin. In fact, the majority of them are the result of cultural norms that have emerged over time. Masturbation, homosexuality, and polygamy are all examples of cultural taboos — however, that is not to say that don’t serve an evolutionary purpose. I’ve heard that homosexuality could be a potential advantage as have a brother that will not produce any offspring can provide support in raising the offspring of his sister.

Religious Morality

   As I mentioned earlier, religion may have the potential to both support and distort human morality. It also has the ability to make additions to moral values such as forbidding the consumption of pork, no sex before marriage, not doing any sort of work on the Sabbath, etc. One purpose for morality may be to help the individual cope with the human condition — to give a meaning their life and avoid an existential crisis — possibly an evolutionary coping mechanism. Possibly a method to reduce death anxiety. Terror Management Theory delves more into this fascinating topic and some have referred to religion itself as a method of terror management.

   If religion is examined from an evolutionary-psychological perspective, one can argue that religion emerged after morality as a ‘support’. Religion has built upon morality by expanding the social scrutiny of individual behavior to include supernatural agents. Including a god that is forever watching ever move you make is an effective strategy for restraining immoral actions as well as creating more cooperative groups (Rossana, 2007). The adaptive value of religion would have enhanced group survival. (Rutherford, 2007).

   Those who lack an understanding of the principles of evolution and philosophy may claim that without religious values prohibiting us from breaking moral laws, we would be living highly unethical lives (i.e. stealing, raping, killing), and we would not feel any remorse or fear of punishment for these actions (one of the signs of someone with antisocial personality disorder).

   It’s also easy to believe that we are qualitatively superior to other species — after all, only humans can have the ability to make moral judgements right? One of the premises that the majority of traditional religious thought is built on is that humans did not evolve from other earlier species of ape, but rather created by an all-powerful god that also commands us to act in a moral fashion. As a result of this dogma, we seem to naturally have this notion that we are superior in almost every aspect, that we are the center of the universe, and that we are the only species with any sort of moral sense. This is a dangerous line of thinking and it is important to question such established doctrines. The ethically questionable subjugation animals aside, it also closes the door to scientific inquiry, skepticism, and establishes the church to being the only human moral authority.

   I do admit that religion may in fact play an important role in human morality — but only when “morality” is loosely defined. It is concerning that some make the propositions that morality and altruism are uniquely human and that it’s rooted in religion. This is not only highly debatable, but false on many levels and circles back to the old fallacy that “god did it” when the unknown cannot be easily explained. The same people also make the inductive leap that morality must have been conferred by God and rejects all socio-biological argument and evidence that morality could be an evolved trait.


   Based on the arguments I’ve presented, there is strong support that moral behavior has a genetic element. Hereditary traits leading to psychological disorders that block moral recognition are indeed a sign that moral values are genetic. The evidence presented also supports that morality is not just a human trait, but is observable in other species as well, most notably altruism. Other animal species behave in an ethical fashion because if they didn’t they would probably die out due to killing their offspring, inbreeding, etc.

   Morality presupposes language and cognition if it exists in animal species, further supporting the idea that there must be an evolutionary trait supporting it. In humans, religious beliefs can potentially support our already structured moral foundations, as well as creating its own set of moral values. I have also presented information that demonstrates the evolutionary benefits to various behaviors that are considered moral (such as altruism), and the biological dangers with behaviors considered immoral (such as incest).

   Although some might argue that explaining morality through a scientific lens dehumanizes our sense of morality, if anything it reinforces what truly is moral and weeds morals that are a product of culture or religion. It may also be attacked on the basis that it reduces personal responsibility in making difficult ethical decisions and gives us excuses when we make a bad decision — of course, this opens up a new discussion about free will. “Tthe devil made me do it” is never the correct response however. Whether or not human morality has an evolutionary cause, it doesn’t change the fact that certain behaviors are ethically wrong and unacceptable and humans should still be held responsible for their actions.

   Morality is an ever-shifting zeitgeist. What was seen as immoral 1000 years ago isn’t considered immoral today. In this essay, I want to emphasize two things: 1) that much of what we consider a moral a product of evolution and 2) culture plays a role in that it expands on what is morality — for better or for worse. Evolutionary theory, science, religion, philosophy, and our natural human instinct to reflect on the world will drive morality into new directions, redefining and altering what is considered acceptable and unacceptable.

Bell, Graham (2008). Selection: the mechanism of evolution. Oxford: Oxford
University Press. pp. 367–368.

Lykken, D. (1995) The Antisocial Personalities

Yang, L., Livesley, W., Rainer, R., Vernon, P., Hu, S., Angleitner, A. . . Hamer,
D. (2001). Covariance structure of neuroticism and agreeableness: a
twin and molecular genetic analysis of the role of the serotonin
transporter gene. Journal of Personality and Social Psychology, 81,

Bowles, S. (2006). Group competition, reproductive leveling, and the evolution of human altruism. Science, 314 (8)

Pinker, S. (2008, January 13). The moral instinct. The New York Times

Rossano, M. (2007). Supernaturalizing social life: religion and the evolution of human cooperation.

Matthew, R. (2007). The evolution of morality. University of Glasgow.