This blog post explores whether shared genes can explain an individual’s altruistic behavior through kin selection theory, examining its limitations and issues.
Introduction
Richard Dawkins’ book ‘The Selfish Gene’ argues that all living beings, including humans, act according to how they are pre-programmed by their genes. Dawkins explains that individuals fulfill the task of passing their genes to the next generation through reproduction, and in this process, they engage in selfish or altruistic behaviors aimed at spreading as many copies of their own genes as possible. Genes help their copies residing in others’ bodies, and this manifests as altruism in the individual. Wilson describes this natural selection as kin selection, positioned between ‘diagnosis selection’ and ‘individual selection,’ arguing that kin selection explains altruistic behavior within families. He states that the closer the kinship, the stronger the altruism. This means that individuals with closer genetic relationships share more genes and thus have a stronger incentive to help copies of themselves.
However, numerous phenomena remain unexplained by kin selection theory. Dawkins asserts that kin selection theory is not problematic, yet many phenomena remain unexplained. The content explained in his works is based on imagination and requires supplementary explanation. Dawkins argues that genes act to maximize the number of copies they leave behind, predicting individual behavior by calculating ‘net payoff’ based on the probability of gene sharing. However, a problem with kin selection theory is that since exact relatedness cannot be calculated, individuals cannot perform altruistic actions based on relatedness. Adoption, imprinting, and moral behavior cannot be explained by kin selection alone, thus limiting the application of Dawkins’ theory to the principles of animal behavior. This essay explains selection among humans and animals that share a blood relationship.
Dawkins’ Kin Selection Theory
Hamilton studied kin selection and explained why individuals prefer altruism through gene sharing, using a simple formula also mentioned in Dawkins’ book ‘The Selfish Gene’. This is a method for calculating whether humans can suppress selfish behavior and engage in altruistic actions at their own expense. He proposed that helping specific kin is understandable if they are sufficiently closely related to share genes, thereby resolving the problem of altruism. Based on Hamilton’s argument, Dawkins biologically explains real-world examples of genetically explained altruistic behavior. The ‘Selfish Gene’ emerged from combining the ideas of George Williams, William Hamilton, and Dawkins. They argue that natural selection, including altruistic behavior, acts solely on genes.
However, Edward Wilson, in his book ‘The Enchantment of Evolution,’ evaluates group selection and claims to have discovered new evidence for the effects of group selection and evolution. He argues that members of a social group must work for each other to become adaptive individuals. However, controversy exists regarding kin selection and group selection. Hamilton argues there is no boundary between them, stating kin selection is a special case of gene selection. Dawkins explains that even when an individual acts altruistically, it does so for the selfishness of its genes. He suggests that when an individual performs altruistic actions toward another, it judges whether that other is a good ‘beneficiary’. Individuals invest part of their resources to measure ‘reproductive expectations’ and calculate whether altruistic behavior is necessary for genes to be passed to the next generation. Dawkins believes genes program individuals, whether human or animal, to behave as if performing complex calculations unconsciously. He suggests predicting individual behavior by calculating the ‘net payoff score’ for specific actions using relatedness, the probability of gene sharing.
Problems with Dawkins’ Kinship Selection Theory
Dawkins’ kinship selection theory claims that individuals exhibit altruistic behavior toward others solely based on genes and kinship. However, this theory has several problems. A key issue is that it fails to logically explain how various factors beyond genetic kinship—such as intimacy, instinct, imprinting, and moral sense—can also trigger behavior to help others. Dawkins did not consider other factors when explaining kin selection, and there are many cases where kin selection does not hold.
It is impossible to know precisely the degree of one’s own genes present in another individual or the exact degree of kinship. Genes cannot act solely based on kinship; Dawkins argues in his book that since the kinship between parents and siblings is the same, the probability of altruistic behavior is also the same. However, this does not align with actual eusocial organisms. For example, a female bee inherits 50% of her mother’s genes but 100% of her father’s genes. Therefore, sisters share an average genetic relatedness of 75%. Comparing the characteristics of hemidiploidy shows this differs from what Dawkins claimed. Since the exact degree of relatedness cannot be known, an individual cannot act altruistically based on relatedness.
Furthermore, when individuals exhibit altruistic behavior toward others, they do so even toward individuals with no blood relation whatsoever. Phenomena such as friendships, volunteer work, romantic relationships, imprinting, adoption, education, and moral behavior cannot be explained by kin selection theory. Most altruistic behavior occurs in the absence of kinship. Dawkins fails to logically explain the case of ducklings born in chicken nests or the phenomenon of ducklings following false parents due to imprinting. Imprinting refers to the phenomenon where newly hatched ducklings follow the first moving object they see, mistaking it for their mother duck. This phenomenon, discovered by Austrian scholar Lorenz, is an instinctive behavior appearing in early infancy; once imprinted on a specific individual during a critical period, it is never forgotten. Dawkins mentions imprinting but fails to explain it logically. While kin selection theory posits that individuals sharing genes exhibit altruistic behavior, imprinting cannot be explained by it.
Another issue with Dawkins’ theory is that it fails to explain altruistic behavior in cases like adoption, where kinship is minimal and genes are not mixed. Adoption involves leaving one’s birth family to grow up in another family group, occurring without any shared genes. Recent studies indicate that adoptive parents tend to care for adopted children better than biological parents. They invest more time and money, feeling pity for the adopted child. However, Dawkins fails to explain why adoptive parents exhibit altruistic behavior toward the child.
We must consider whether altruistic behavior stems from shared genes or from increasing the probability of passing one’s genes to the next generation. Dawkins did not account for multiple variables when explaining kin selection. He calculates only relatedness, life expectancy, and efficiency, yet even these variables are explanations based on imagination without precise evidence. Dawkins’ model is simplistic; it fails to explain exceptional phenomena and merely mentions their existence.
Principles explaining selection among related individuals
Kin selection alone cannot explain selection in humans and animals. Depending on the situation, genetic influences may exist, or environmental influences may exist. Animal selection behavior is influenced by various environmental factors beyond genetic relatedness. Besides kin selection, there are environmental factor theories and group selection. Since ancient times, humans have been born under the direct influence of their environment, which affects not only their activities but also their mental states.
Environmental determinism, proposed by German geographer Friedrich Ratzel, posits that the activities of humans and animals are strongly influenced by their environment, leading to regionalism as an adaptation to these conditions. The environment is broadly divided into abiotic and biotic components. The abiotic environment includes physical factors such as light, temperature, climate, moisture, air, and soil, along with chemical factors. The biotic environment refers to elements that exert direct or indirect influence. An individual’s life is governed by the interplay between environment and organisms, forming a social structure where life is divided temporally and spatially. Individuals engage in activities with others not based on kinship but due to shared abiotic and biotic environments. Dawkins’ theory of kin selection failed to explain why individuals who do not share genes exhibit altruistic behavior. Environmental determinism can fill this gap in his theory and logically explain animal selection.
Edward Wilson refutes Dawkins’ kin selection, arguing that altruistic behavior or cooperation arises from group selection. Wilson refutes kin selection using ants as an example, stating that while ants sacrifice themselves for the queen and risk their own lives, this is achieved through cooperation and defection. He argues that cooperation cannot be explained by the evolutionary theory of kin selection, signaling theory, or altruism theory. According to Wilson, cooperative behavior is heritable, and humans are a social process created through group selection. He asserts that cooperative instincts are inherently embedded in humans.
Dawkins defines kin selection as altruistic behavior toward close relatives to propagate genes. He explains that the closer the genetic relationship, the higher the probability of altruistic behavior. However, one must consider whether altruism arises solely because of shared genes. Dawkins overlooked several factors in explaining kin selection and failed to fully account for altruistic behavior between individuals who do not share genes, such as in imprinting or adoption. Environmental determinism and group selection can be used to supplement this explanation.
Conclusion
Kin selection is a theory explaining that individuals exhibit altruistic behavior toward kin when relatedness is high. Dawkins uses kin selection theory to explain why humans or animals exhibit altruistic behavior toward other individuals. He defined genetic relatedness as the proportion of genes shared between oneself and another individual. Parents and children share 1/2, siblings share an average of 1/2. Dawkins argues that kin selection provides a natural explanation, but the theory fails to account for all behaviors between related individuals in animals. Beyond genetic relatedness, Dawkins fails to account for how various factors like familiarity, instinct, imprinting, morality, and adoption also trigger helping behaviors.
The problem with Dawkins’ kin selection theory is that it assumes the selfishness of genes and calculates ‘net payoff’ based on relatedness. Since there is no way to know exact relatedness, one cannot act based on genetic relatedness. Furthermore, helping behavior occurs even when individuals share no genes. Imprinting, adoption, and moral behavior cannot be explained by kin selection, and Dawkins has not proposed alternative theories.
To explain selection between individuals, a logical approach is necessary. This requires applying various theories to understand which factors strongly influence behavior in different situations. Animals are subject to diverse environmental influences, which must be considered, and it must be determined whether each influence can be quantified. Among other theories are group selection and environmental determinism. Group selection, as proposed by Wilson, posits that altruism is an instinct created by organisms desiring the common good, not kinship. Groups possessing cooperation and empathy are said to significantly influence the survival of competing groups. Environmental determinism posits that humans, when active in natural environments, are subject to diverse influences, leading to regionalism as an adaptive response. Environmental determinism is divided into abiotic and biotic environments. Interactions arising from the biotic environment, in particular, occur due to factors other than kinship.
Dawkins’ kin selection is not the only theory explaining animal selection. It must be applied in combination with various environmental factors. Dawkins’ kin selection is the result of observing animal selection solely from one perspective. However, he did not sufficiently consider other factors and cannot logically explain altruistic behavior occurring between unrelated individuals. This essay identifies the problems with the theory of kin selection and argues that selection between related individuals must be applied in a complex manner.
