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Sociobiology is a field of biology that aims to explain social behavior in terms of evolution. It draws from disciplines including psychology, ethology, anthropology, evolution, zoology, archaeology, and population genetics. Within the study of human societies, sociobiology is closely allied to evolutionary anthropology, human behavioral ecology, evolutionary psychology, [1] and sociology. [2] [3]
Sociobiology investigates social behaviors such as mating patterns, territorial fights, pack hunting, and the hive society of social insects. It argues that just as selection pressure led to animals evolving useful ways of interacting with the natural environment, so also it led to the genetic evolution of advantageous social behavior. [4]
While the term "sociobiology" originated at least as early as the 1940s; the concept did not gain major recognition until the publication of E. O. Wilson's book Sociobiology: The New Synthesis in 1975. The new field quickly became the subject of controversy. Critics, led by Richard Lewontin and Stephen Jay Gould, argued that genes played a role in human behavior, but that traits such as aggressiveness could be explained by social environment rather than by biology. Sociobiologists responded by pointing to the complex relationship between nature and nurture. Among sociobiologists, the controversy between laying weight to different levels of selection was settled between D.S. Wilson and E.O. Wilson in 2007. [5]
E. O. Wilson defined sociobiology as "the extension of population biology and evolutionary theory to social organization". [6]
Sociobiology is based on the premise that some behaviors (social and individual) are at least partly inherited and can be affected by natural selection. [7] It begins with the idea that behaviors have evolved over time, similar to the way that physical traits are thought to have evolved. It predicts that animals will act in ways that have proven to be evolutionarily successful over time. This can, among other things, result in the formation of complex social processes conducive to evolutionary fitness.
The discipline seeks to explain behavior as a product of natural selection. Behavior is therefore seen as an effort to preserve one's genes in the population. Inherent in sociobiological reasoning is the idea that certain genes or gene combinations that influence particular behavioral traits can be inherited from generation to generation. [5]
For example, newly dominant male lions often kill cubs in the pride that they did not sire. This behavior is adaptive because killing the cubs eliminates competition for their own offspring and causes the nursing females to come into heat faster, thus allowing more of his genes to enter into the population. Sociobiologists would view this instinctual cub-killing behavior as being inherited through the genes of successfully reproducing male lions, whereas non-killing behavior may have died out as those lions were less successful in reproducing. [8]
The philosopher of biology Daniel Dennett suggested that the political philosopher Thomas Hobbes was the first proto-sociobiologist, arguing that in his 1651 book Leviathan Hobbes had explained the origins of morals in human society from an amoral sociobiological perspective. [9]
The geneticist of animal behavior John Paul Scott coined the word sociobiology at a 1948 conference on genetics and social behavior, which called for a conjoint development of field and laboratory studies in animal behavior research. [10] With John Paul Scott's organizational efforts, a "Section of Animal Behavior and Sociobiology" of the Ecological Society of America was created in 1956, which became a Division of Animal Behavior of the American Society of Zoology in 1958. In 1956, E. O. Wilson came in contact with this emerging sociobiology through his PhD student Stuart A. Altmann, who had been in close relation with the participants to the 1948 conference. Altmann developed his own brand of sociobiology to study the social behavior of rhesus macaques, using statistics, and was hired as a "sociobiologist" at the Yerkes Regional Primate Research Center in 1965. Wilson's sociobiology is different from John Paul Scott's or Altmann's, insofar as he drew on mathematical models of social behavior centered on the maximization of the genetic fitness by W. D. Hamilton, Robert Trivers, John Maynard Smith, and George R. Price. The three sociobiologies by Scott, Altmann and Wilson have in common to place naturalist studies at the core of the research on animal social behavior and by drawing alliances with emerging research methodologies, at a time when "biology in the field" was threatened to be made old-fashioned by "modern" practices of science (laboratory studies, mathematical biology, molecular biology). [11]
Once a specialist term, "sociobiology" became widely known in 1975 when Wilson published his book Sociobiology: The New Synthesis, which sparked an intense controversy. Since then "sociobiology" has largely been equated with Wilson's vision. The book pioneered and popularized the attempt to explain the evolutionary mechanics behind social behaviors such as altruism, aggression, and nurturance, primarily in ants (Wilson's own research specialty) and other Hymenoptera, but also in other animals. However, the influence of evolution on behavior has been of interest to biologists and philosophers since soon after the discovery of evolution itself. Peter Kropotkin's Mutual Aid: A Factor of Evolution , written in the early 1890s, is a popular example. The final chapter of the book is devoted to sociobiological explanations of human behavior, and Wilson later wrote a Pulitzer Prize winning book, On Human Nature , that addressed human behavior specifically. [12]
Edward H. Hagen writes in The Handbook of Evolutionary Psychology that sociobiology is, despite the public controversy regarding the applications to humans, "one of the scientific triumphs of the twentieth century." "Sociobiology is now part of the core research and curriculum of virtually all biology departments, and it is a foundation of the work of almost all field biologists. " Sociobiological research on nonhuman organisms has increased dramatically and continuously in the world's top scientific journals such as Nature and Science . The more general term behavioral ecology is commonly substituted for the term sociobiology in order to avoid the public controversy. [13]
Sociobiologists maintain that human behavior, as well as nonhuman animal behavior, can be partly explained as the outcome of natural selection. They contend that in order to fully understand behavior, it must be analyzed in terms of evolutionary considerations.
Natural selection is fundamental to evolutionary theory. Variants of hereditary traits which increase an organism's ability to survive and reproduce will be more greatly represented in subsequent generations, i.e., they will be "selected for". Thus, inherited behavioral mechanisms that allowed an organism a greater chance of surviving and/or reproducing in the past are more likely to survive in present organisms. That inherited adaptive behaviors are present in nonhuman animal species has been multiply demonstrated by biologists, and it has become a foundation of evolutionary biology. However, there is continued resistance by some researchers over the application of evolutionary models to humans, particularly from within the social sciences, where culture has long been assumed to be the predominant driver of behavior.
Sociobiology is based upon two fundamental premises:
Sociobiology uses Nikolaas Tinbergen's four categories of questions and explanations of animal behavior. Two categories are at the species level; two, at the individual level. The species-level categories (often called "ultimate explanations") are
The individual-level categories (often called "proximate explanations") are
Sociobiologists are interested in how behavior can be explained logically as a result of selective pressures in the history of a species. Thus, they are often interested in instinctive, or intuitive behavior, and in explaining the similarities, rather than the differences, between cultures. For example, mothers within many species of mammals – including humans – are very protective of their offspring. Sociobiologists reason that this protective behavior likely evolved over time because it helped the offspring of the individuals which had the characteristic to survive. This parental protection would increase in frequency in the population. The social behavior is believed to have evolved in a fashion similar to other types of nonbehavioral adaptations, such as a coat of fur, or the sense of smell.
Individual genetic advantage fails to explain certain social behaviors as a result of gene-centred selection. E.O. Wilson argued that evolution may also act upon groups. [14] The mechanisms responsible for group selection employ paradigms and population statistics borrowed from evolutionary game theory. Altruism is defined as "a concern for the welfare of others". If altruism is genetically determined, then altruistic individuals must reproduce their own altruistic genetic traits for altruism to survive, but when altruists lavish their resources on non-altruists at the expense of their own kind, the altruists tend to die out and the others tend to increase. An extreme example is a soldier losing his life trying to help a fellow soldier. This example raises the question of how altruistic genes can be passed on if this soldier dies without having any children. [15]
Within sociobiology, a social behavior is first explained as a sociobiological hypothesis by finding an evolutionarily stable strategy that matches the observed behavior. Stability of a strategy can be difficult to prove, but usually, it will predict gene frequencies. The hypothesis can be supported by establishing a correlation between the gene frequencies predicted by the strategy, and those expressed in a population.
Altruism between social insects and littermates has been explained in such a way. Altruistic behavior, behavior that increases the reproductive fitness of others at the apparent expense of the altruist, in some animals has been correlated to the degree of genome shared between altruistic individuals. A quantitative description of infanticide by male harem-mating animals when the alpha male is displaced as well as rodent female infanticide and fetal resorption are active areas of study. In general, females with more bearing opportunities may value offspring less, and may also arrange bearing opportunities to maximize the food and protection from mates.
An important concept in sociobiology is that temperament traits exist in an ecological balance. Just as an expansion of a sheep population might encourage the expansion of a wolf population, an expansion of altruistic traits within a gene pool may also encourage increasing numbers of individuals with dependent traits.
Studies of human behavior genetics have generally found behavioral traits such as creativity, extroversion, aggressiveness, and IQ have high heritability. The researchers who carry out those studies are careful to point out that heritability does not constrain the influence that environmental or cultural factors may have on those traits. [16] [17]
Various theorists have argued that in some environments criminal behavior might be adaptive. [18] The evolutionary neuroandrogenic (ENA) theory, by sociologist/criminologist Lee Ellis, posits that female sexual selection has led to increased competitive behavior among men, sometimes resulting in criminality. In another theory, Mark van Vugt argues that a history of intergroup conflict for resources between men have led to differences in violence and aggression between men and women. [19] The novelist Elias Canetti also has noted applications of sociobiological theory to cultural practices such as slavery and autocracy. [20]
Genetic mouse mutants illustrate the power that genes exert on behavior. For example, the transcription factor FEV (aka Pet1), through its role in maintaining the serotonergic system in the brain, is required for normal aggressive and anxiety-like behavior. [21] Thus, when FEV is genetically deleted from the mouse genome, male mice will instantly attack other males, whereas their wild-type counterparts take significantly longer to initiate violent behavior. In addition, FEV has been shown to be required for correct maternal behavior in mice, such that offspring of mothers without the FEV factor do not survive unless cross-fostered to other wild-type female mice. [22]
A genetic basis for instinctive behavioral traits among non-human species, such as in the above example, is commonly accepted among many biologists; however, attempting to use a genetic basis to explain complex behaviors in human societies has remained extremely controversial. [23] [24]
Steven Pinker argues that critics have been overly swayed by politics and a fear of biological determinism, [lower-alpha 1] accusing among others Stephen Jay Gould and Richard Lewontin of being "radical scientists", whose stance on human nature is influenced by politics rather than science, [26] while Lewontin, Steven Rose and Leon Kamin, who drew a distinction between the politics and history of an idea and its scientific validity, [27] argue that sociobiology fails on scientific grounds. Gould grouped sociobiology with eugenics, criticizing both in his book The Mismeasure of Man . [28] When Napoleon Chagnon scheduled sessions on sociobiology at the 1976 American Anthropological Association convention, other scholars attempted to cancel them with what Chagnon later described as "Impassioned accusations of racism, fascism and Nazism"; Margaret Mead's support caused the sessions to occur as scheduled. [29]
Noam Chomsky has expressed views on sociobiology on several occasions. During a 1976 meeting of the Sociobiology Study Group, as reported by Ullica Segerstråle, Chomsky argued for the importance of a sociobiologically informed notion of human nature. [30] Chomsky argued that human beings are biological organisms and ought to be studied as such, with his criticism of the "blank slate" doctrine in the social sciences (which would inspire a great deal of Steven Pinker's and others' work in evolutionary psychology), in his 1975 Reflections on Language . [31] Chomsky further hinted at the possible reconciliation of his anarchist political views and sociobiology in a discussion of Peter Kropotkin's Mutual Aid: A Factor of Evolution , which focused more on altruism than aggression, suggesting that anarchist societies were feasible because of an innate human tendency to cooperate. [32]
Wilson has claimed that he had never meant to imply what ought to be, only what is the case. However, some critics have argued that the language of sociobiology readily slips from "is" to "ought", [27] an instance of the naturalistic fallacy. Pinker has argued that opposition to stances considered anti-social, such as ethnic nepotism, is based on moral assumptions, meaning that such opposition is not falsifiable by scientific advances. [33] The history of this debate, and others related to it, are covered in detail by Cronin (1993), Segerstråle (2000), and Alcock (2001).
Evolutionary psychology is a theoretical approach in psychology that examines cognition and behavior from a modern evolutionary perspective. It seeks to identify human psychological adaptations with regards to the ancestral problems they evolved to solve. In this framework, psychological traits and mechanisms are either functional products of natural and sexual selection or non-adaptive by-products of other adaptive traits.
The Selfish Gene is a 1976 book on evolution by ethologist Richard Dawkins, in which the author builds upon the principal theory of George C. Williams's Adaptation and Natural Selection (1966). Dawkins uses the term "selfish gene" as a way of expressing the gene-centred view of evolution, popularising ideas developed during the 1960s by W. D. Hamilton and others. From the gene-centred view, it follows that the more two individuals are genetically related, the more sense it makes for them to behave cooperatively with each other.
Biological determinism, also known as genetic determinism, is the belief that human behaviour is directly controlled by an individual's genes or some component of their physiology, generally at the expense of the role of the environment, whether in embryonic development or in learning. Genetic reductionism is a similar concept, but it is distinct from genetic determinism in that the former refers to the level of understanding, while the latter refers to the supposed causal role of genes. Biological determinism has been associated with movements in science and society including eugenics, scientific racism, and the debates around the heritability of IQ, the basis of sexual orientation, and evolutionary foundations of cooperation in sociobiology.
Kin selection is a process whereby natural selection favours a trait due to its positive effects on the reproductive success of an organism's relatives, even when at a cost to the organism's own survival and reproduction. Kin selection can lead to the evolution of altruistic behaviour. It is related to inclusive fitness, which combines the number of offspring produced with the number an individual can ensure the production of by supporting others. A broader definition of kin selection includes selection acting on interactions between individuals who share a gene of interest even if the gene is not shared due to common ancestry.
Group selection is a proposed mechanism of evolution in which natural selection acts at the level of the group, instead of at the level of the individual or gene.
In evolutionary biology, inclusive fitness is one of two metrics of evolutionary success as defined by W. D. Hamilton in 1964:
Sociobiology: The New Synthesis is a book by the biologist E. O. Wilson. It helped start the sociobiology debate, one of the great scientific controversies in biology of the 20th century and part of the wider debate about evolutionary psychology and the modern synthesis of evolutionary biology. Wilson popularized the term "sociobiology" as an attempt to explain the evolutionary mechanics behind social behaviour such as altruism, aggression, and the nurturing of the young. It formed a position within the long-running nature versus nurture debate. The fundamental principle guiding sociobiology is that an organism's evolutionary success is measured by the extent to which its genes are represented in the next generation.
Not in Our Genes: Biology, Ideology and Human Nature is a 1984 book by the evolutionary geneticist Richard Lewontin, the neurobiologist Steven Rose, and the psychologist Leon Kamin, in which the authors criticize sociobiology and genetic determinism and advocate a socialist society. Its themes include the relationship between biology and society, the nature versus nurture debate, and the intersection of science and ideology.
The gene-centered view of evolution, gene's eye view, gene selection theory, or selfish gene theory holds that adaptive evolution occurs through the differential survival of competing genes, increasing the allele frequency of those alleles whose phenotypic trait effects successfully promote their own propagation. The proponents of this viewpoint argue that, since heritable information is passed from generation to generation almost exclusively by DNA, natural selection and evolution are best considered from the perspective of genes.
In biology, altruism refers to behaviour by an individual that increases the fitness of another individual while decreasing their own. Altruism in this sense is different from the philosophical concept of altruism, in which an action would only be called "altruistic" if it was done with the conscious intention of helping another. In the behavioural sense, there is no such requirement. As such, it is not evaluated in moral terms—it is the consequences of an action for reproductive fitness that determine whether the action is considered altruistic, not the intentions, if any, with which the action is performed.
Evolutionary ethics is a field of inquiry that explores how evolutionary theory might bear on our understanding of ethics or morality. The range of issues investigated by evolutionary ethics is quite broad. Supporters of evolutionary ethics have argued that it has important implications in the fields of descriptive ethics, normative ethics, and metaethics.
On Human Nature is a book by the biologist E. O. Wilson, in which the author attempts to explain human nature and society through sociobiology. Wilson argues that evolution has left its traces on characteristics such as generosity, self-sacrifice, worship and the use of sex for pleasure, and proposes a sociobiological explanation of homosexuality.
Evolutionary psychology seeks to identify and understand human psychological traits that have evolved in much the same way as biological traits, through adaptation to environmental cues. Furthermore, it tends toward viewing the vast majority of psychological traits, certainly the most important ones, as the result of past adaptions, which has generated significant controversy and criticism from competing fields. These criticisms include disputes about the testability of evolutionary hypotheses, cognitive assumptions such as massive modularity, vagueness stemming from assumptions about the environment that leads to evolutionary adaptation, the importance of non-genetic and non-adaptive explanations, as well as political and ethical issues in the field itself.
The concept of the evolution of morality refers to the emergence of human moral behavior over the course of human evolution. Morality can be defined as a system of ideas about right and wrong conduct. In everyday life, morality is typically associated with human behavior rather than animal behavior. The emerging fields of evolutionary biology, and in particular evolutionary psychology, have argued that, despite the complexity of human social behaviors, the precursors of human morality can be traced to the behaviors of many other social animals. Sociobiological explanations of human behavior remain controversial. Social scientists have traditionally viewed morality as a construct, and thus as culturally relative, although others such as Sam Harris argue that there is an objective science of morality.
The history of evolutionary psychology began with Charles Darwin, who said that humans have social instincts that evolved by natural selection. Darwin's work inspired later psychologists such as William James and Sigmund Freud but for most of the 20th century psychologists focused more on behaviorism and proximate explanations for human behavior. E. O. Wilson's landmark 1975 book, Sociobiology, synthesized recent theoretical advances in evolutionary theory to explain social behavior in animals, including humans. Jerome Barkow, Leda Cosmides and John Tooby popularized the term "evolutionary psychology" in their 1992 book The Adapted Mind: Evolutionary Psychology and The Generation of Culture. Like sociobiology before it, evolutionary psychology has been embroiled in controversy, but evolutionary psychologists see their field as gaining increased acceptance overall.
The theoretical foundations of evolutionary psychology are the general and specific scientific theories that explain the ultimate origins of psychological traits in terms of evolution. These theories originated with Charles Darwin's work, including his speculations about the evolutionary origins of social instincts in humans. Modern evolutionary psychology, however, is possible only because of advances in evolutionary theory in the 20th century.
Darwinian anthropology describes an approach to anthropological analysis which employs various theories from Darwinian evolutionary biology. Whilst there are a number of areas of research that can come under this broad description some specific research projects have been closely associated with the label. A prominent example is the project that developed in the mid 1970s with the goal of applying sociobiological perspectives to explain patterns of human social relationships, particularly kinship patterns across human cultures.
Inclusive fitness in humans is the application of inclusive fitness theory to human social behaviour, relationships and cooperation.
Social selection is a term used with varying meanings in biology.
Reciprocal altruism in humans refers to an individual behavior that gives benefit conditionally upon receiving a returned benefit, which draws on the economic concept – ″gains in trade″. Human reciprocal altruism would include the following behaviors : helping patients, the wounded, and the others when they are in crisis; sharing food, implement, knowledge.
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Moreover, even highly heritable traits can be strongly manipulated by the environment, so heritability has little if anything to do with controllability. For example, height is on the order of 90% heritable, yet North and South Koreans, who come from the same genetic background, presently differ in average height by a full 6 inches (Pak, 2004; Schwekendiek, 2008).
But back to the question: What does heritability mean? Almost everyone who has ever thought about heritability has reached a commonsense intuition about it: One way or another, heritability has to be some kind of index of how genetic a trait is. That intuition explains why so many thousands of heritability coefficients have been calculated over the years. . . . Unfortunately, that fundamental intuition is wrong. Heritability isn't an index of how genetic a trait is. A great deal of time has been wasted in the effort of measuring the heritability of traits in the false expectation that somehow the genetic nature of psychological phenomena would be revealed.
A surprising number of intellectuals, particularly on the left, do deny that there is such a thing as inborn talent, especially intelligence. Stephen Jay Gould's 191 bestseller The Mismeasure of Man was written to debunk 'the abstraction of intelligence as a single entity ... and the use of these numbers to rank people in a single series of worthiness'
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