AskDefine | Define sociobiology

Dictionary Definition

sociobiology n : the branch of biology that conducts comparative studies of the social organization of animals (including human beings) with regard to its evolutionary history

User Contributed Dictionary



  1. The science that applies the principles of evolutionary biology to the study of social behaviour in both humans and animals

Extensive Definition

Sociobiology is a neo-Darwinian synthesis of scientific disciplines that attempts to explain social behavior in all species by considering the evolutionary advantages the behaviors may have. It is often considered a branch of biology and sociology, but also draws from ethology, anthropology, evolution, zoology, archaeology, population genetics and other disciplines. Within the study of human societies, sociobiology is closely related to the fields of human behavioral ecology and evolutionary psychology.
Sociobiology investigates social behaviors, such as mating patterns, territorial fights, pack hunting, and the hive society of social insects. Just as selection pressure led to animals evolving useful ways of interacting with the natural environment, it led to the genetic evolution of advantageous social behavior. Applied to nonhumans, sociobiology is noncontroversial.
Sociobiology has become one of the greatest scientific controversies of the late 20th and early 21st centuries, especially in the context of explaining human behavior. Criticism, most notably made by Richard Lewontin and Stephen Jay Gould, centers on sociobiology's contention that genes play a central role in human behavior and that variation in traits such as aggressiveness can be explained by variation in peoples' biology and is not necessarily a product of the person's social environment. Many sociobiologists, however, cite a complex relationship between nature and nurture. In response to the controversy, anthropologist John Tooby and psychologist Leda Cosmides launched evolutionary psychology as a branch of sociobiology made less controversial avoiding questions of human biodiversity.


Sociobiology is based on the idea that some behaviors (both social and individual) are at least partly inherited and can be affected by natural selection. It starts with the idea that these behaviors have evolved over time, similar to the way that physical traits are thought to have evolved. Therefore, it predicts that animals will act in ways that have proven to be evolutionarily successful over time, which can among other things result in the formation of complex social processes that have proven to be conducive to evolutionary fitness.
The discipline seeks to explain behavior as a product of natural selection, thus behavior is 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 "passed down" from generation to generation.

Introductory example

For example, newly dominant male lions often will kill cubs in the pride that were not sired by them. This behavior is adaptive in evolutionary terms 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 "passed down" through the genes of successfully reproducing male lions, whereas non-killing behavior may have "died out" as those lions were less successful in reproducing.
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.


The word "sociobiology" was coined by John Paul Scott in 1946, at a conference on genetics and social behaviour, and became widely used after it was popularized by Edward O. Wilson in his 1975 book, Sociobiology: The New Synthesis. Antecedents of sociobiological thinking can be traced to the work of Robert Trivers and William D. Hamilton. Wilson's book pioneered and popularized the attempt to explain the evolutionary mechanics behind social behaviors such as altruism, aggression, and nurturence, primarily in ants (Wilson's own research specialty) but also in other animals. 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.

Sociobiological theory

Sociobiologists believe that human behavior, as well as nonhuman animal behavior, can be partly explained as the outcome of natural selection. They contend that in order fully to understand behavior, it must be analyzed in terms of evolutionary considerations.
Natural selection is considered fundamental to evolutionary theory, and asserts that 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 would be more likely to survive in present organisms. Many biologists accept that inherited adaptive behaviors are present in nonhuman animal species. However, there is a great deal of controversy over the application of evolutionary models to humans both within evolutionary biology itself and the social sciences.
Sociobiology is based upon two fundamental premises:
  • Certain behavioral traits are inherited,
  • Inherited behavioral traits have been honed by natural selection. Therefore, these traits were probably "adaptive" in the species` evolutionarily evolved environment.
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 function (i.e., adaptation) that a behavior serves and
  • the evolutionary process (i.e., phylogeny) that resulted in this functionality.
The individual-level categories are
  • the development of the individual (i.e., ontogeny) and
  • the proximate mechanism (e.g., brain anatomy and hormones).
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 those individuals which had the characteristic to survive and reproduce. Over time, individuals of species that did not exhibit such protective behaviors likely lost their offspring and ultimately died out. In this way, the social behavior is believed to have evolved in a fashion similar to other types of nonbehavioral adaptations, such as (for example) fur or the sense of smell.
Individual genetic advantage often fails to explain certain social behaviors as a result of gene-centred selection, and evolution may also act upon groups. The mechanisms responsible for group selection employ paradigms and population statistics borrowed from game theory. E.O. Wilson argued that altruistic individuals must reproduce their own altruistic genetic traits for altruism to survive. 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 grow. In other words, altruists must practice the ethic that "charity begins at home."
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, a well-formed strategy 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. Measurement of genes and gene-frequencies can be problematic, however, because a simple statistical correlation can be open to charges of circularity (Circularity can occur if the measurement of gene frequency indirectly uses the same measurements that describe the strategy).
Altruism between social insects and littermates has been explained in such a way. Altruistic behavior 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. Female infanticide and fetal resorption in rodents are active areas of study. In general, females with more bearing opportunities may value offspring less. Also, females may arrange bearing opportunities to maximize the food and protection from mates.
An important concept in sociobiology is that temperamental traits within a gene pool and between gene pools 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 the expansion of individuals with dependent traits.




  • Alcock, John (2001). The Triumph of Sociobiology. Oxford: Oxford University Press. Directly rebuts several of the above criticisms and misconceptions listed above.
  • Barkow, Jerome (Ed.). (2006) Missing the Revolution: Darwinism for Social Scientists. Oxford: Oxford University Press.
  • Cronin, H. (1992). The Ant and the Peacock: Altruism and Sexual Selection from Darwin to Today. Cambridge: Cambridge University Press.
  • Pinker, S. (2002). The Blank Slate: The Modern Denial of Human Nature. New York: Viking.
  • Richards, Janet Radcliffe (2000). Human Nature After Darwin: A Philosophical Introduction. London: Routledge.
  • Segerstråle, Ullica (2000). Defenders of the Truth: The Battle for Science in the Sociobiology Debate and Beyond. Oxford: Oxford University Press.
  • Biology, Ideology and Human Nature: Not In Our Genes
  • Gene Worship: Moving Beyond the Nature/Nurture Debate over Genes, Brain, and Gender
  • Final Solutions: Biology, Prejudice, and Genocide
  • Survival of the Prettiest: The Science of Beauty

External links

sociobiology in Danish: Sociobiologi
sociobiology in German: Soziobiologie
sociobiology in Estonian: Sotsiobioloogia
sociobiology in Spanish: Sociobiología
sociobiology in French: Sociobiologie
sociobiology in Italian: Sociobiologia
sociobiology in Hungarian: Szociobiológia
sociobiology in Dutch: Sociobiologie
sociobiology in Japanese: 社会生物学
sociobiology in Norwegian: Sosiobiologi
sociobiology in Polish: Socjobiologia
sociobiology in Portuguese: Sociobiologia
sociobiology in Russian: Социобиология
sociobiology in Finnish: Sosiobiologia
sociobiology in Chinese: 社會生物學
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