The global brain is a metaphor for the worldwide intelligent network formed by all the individuals on this planet, together with the information and communication technologies that connect them into a self-organizing whole. As the internet becomes faster, more intelligent, and more encompassing, it increasingly ties us together into a single information processing system, which functions like a nervous system for the planet Earth. The intelligence of this network is collective or distributed: it is not centralized or localized in any particular individual, organization or computer system. It rather emerges from the dynamic networks of interactions between its components, a property typical of complex adaptive systems.
The World-wide web in particular resembles the organization of a brain with its webpages (playing a role similar to neurons) connected by hyperlinks (playing a role similar to synapses), together forming an associative network along which information propagates. This analogy becomes stronger with the rise of social media, such as Facebook, where links between personal pages represent relationships in a social network along which information propagates from person to person. Such propagation is similar to the spreading activation that neural networks in the brain use to process information in a parallel, distributed manner.
Although the underlying ideas are much older, the term "global brain" was coined in 1982 by Peter Russell in his book The Global Brain. How the Internet might be developed to achieve this was set out in 1986 . The first peer-refereed article on the subject was written by Mayer-Kress and Barczys in 1995, while the first algorithms that could turn the world-wide web into a collectively intelligent network were proposed by Francis Heylighen and Johan Bollen in 1996.
Historical conceptions 
Francis Heylighen reviewed the history of the concept and its usage. In this work he distinguished four perspectives on the global brain, "organicism", "encyclopedism", "emergentism" and "evolutionary cybernetics", that developed relatively independently but that now appear to come together in a single conception.
In the 19th century, the sociologist Herbert Spencer saw society as a social organism and reflected about its need for a nervous system. Entomologist William Wheeler developed the concept of the ant colony as a spatially extended organism, and in the 1930s he coined the term superorganism to describe such an entity. This concept was later adopted by thinkers such as Gregory Stock in his book Metaman and Joel de Rosnay to describe planetary society as a superorganism.
The mental aspects of such an organic system at the planetary level were perhaps first broadly elaborated by paleontologist and Jesuit priest Pierre Teilhard de Chardin. In 1945, he described a coming "planetisation" of humanity, which he saw as the next phase of accelerating human "socialisation" (British spellings). Teilhard described both socialization and planetization as irreversible, irresistible processes of macrobiological development culminating in the emergence of a noosphere, or global mind (see Emergentism below).
In the perspective of encylopedism, the emphasis is on developing a universal knowledge network. The first attempt to create such an integrated system of the world's knowledge was the Encyclopédie of Denis Diderot and Jean le Rond d'Alembert. However, by the end of the 19th century, the amount of knowledge had become too large to be published in a single synthetic volume. To tackle this problem, Paul Otlet founded the science of documentation, now called information science, eventually envisaging a World Wide Web-like interface that would make all the world's knowledge available immediately to anybody. H. G. Wells proposed the similar idea of a collaboratively developed world encyclopedia, which he called a World Brain, as it would function as a continuously updated memory for the planet.
Tim Berners-Lee, the inventor of the World Wide Web, too, was inspired by the free associative possibilities of the brain for his invention. The brain can link different kinds of information without any apparent link otherwise; Berners-Lee thought that computers could become much more powerful if they could imitate this functioning, i.e. make links between any arbitrary piece of information. The most powerful implementation of encyclopedism to date is Wikipedia, which integrates the associative powers of the world-wide web with the collective intelligence of its millions of contributors, so as to produce a true "global memory" describing the world in all its aspects.
This approach focuses on the emergent aspects of the evolution and development of complexity, including the spiritual, psychological, and moral-ethical aspects of the global brain. This is at present a particularly abstract and speculative domain. The global brain is here seen as a natural and emergent process of planetary evolutionary development. Here again Pierre Teilhard de Chardin attempted a synthesis of science, social values, and religion in his The Phenomenon of Man, which argues that the telos (drive, purpose) of universal evolutionary process is the development of greater levels of both complexity and consciousness. Teilhard proposed that if life persists then planetization, as a biological process producing a global brain, would necessarily also produce a global mind, a new level of planetary consciousness and a technologically-supported network of thoughts which he called the noosphere. Teilhard's proposed technological layer for the noosphere can be interpreted as an early anticipation of the Internet and the Web.
Physicist and philosopher Peter Russell elaborates a similar view, and stresses the importance of personal spiritual growth, in order to build and to achieve synergy with the spiritual dimension of the emerging superorganism. This approach is most popular in New Age circles, which emphasize growth in consciousness rather than scientific modeling or the implementation of technological and social systems.
Evolutionary cybernetics 
Systems theorists and cyberneticists commonly describe the emergence of a higher order system in evolutionary development as a "metasystem transition" (a concept introduced by Valentin Turchin) or a "major evolutionary transition". Such a metasystem consists of a group of subsystems that work together in a coordinated, goal-directed manner. It is as such much more powerful and intelligent than its constituent systems. Francis Heylighen has argued that the global brain is an emerging metasystem with respect to the level of individual human intelligence, and investigated the specific evolutionary mechanisms that promote this transition
In this scenario, the Internet fulfills the role of the network of "nerves" that interconnect the subsystems and thus coordinates their activity. The cybernetic approach makes it possible to develop mathematical models and simulations of the processes of self-organization through which such coordination and collective intelligence emerges.
Recent developments 
In 1996, Francis Heylighen and Ben Goertzel founded the Global Brain group, a discussion forum grouping most of the researchers that had been working on the subject of the global brain to further investigate this phenomenon. The group organized the first international conference on the topic in 2001 at the Vrije Universiteit Brussel.
After a period of relative neglect, the Global Brain idea has recently seen a resurgence in interest, in part due to talks given on the topic by Tim O'Reilly, the Internet forecaster who popularized the term Web 2.0, and Yuri Milner, the social media investor. In January 2012, the Global Brain Institute (GBI) was founded at the Vrije Universiteit Brussel to develop a mathematical theory of the "brainlike" propagation of information across the Internet. In the same year, Thomas W. Malone and collaborators from the MIT Center for Collective Intelligence have started to explore how the global brain could be "programmed" to work more effectively, using mechanisms of collective intelligence.
A common criticism of the idea that humanity would become directed by a global brain is that this would reduce individual freedom and diversity. Moreover, the global brain might start to play the role of Big Brother, the all-seeing eye of the system that follows every person's move. This criticism is inspired by totalitarian and collectivist forms of government, like the ones found in Joseph Stalin's Soviet Union or Mao Zedong's China. It is also inspired by the analogy between collective intelligence or swarm intelligence and insect societies, such as beehives and ant colonies in which individuals are essentially interchangeable. In a more extreme view, the global brain has been compared with the Borg, the race of collectively thinking cyborgs imagined by the creators of the Star Trek science fiction series.
Global brain theorists reply that the emergence of distributed intelligence would lead to the exact opposite of this vision,. The reason is that effective collective intelligence requires diversity, decentralization and individual independence, as demonstrated by James Surowiecki in his book The Wisdom of Crowds. Moreover, a more distributed form of decision-making would decrease the power of governments, corporations or political leaders, thus increasing democratic participation and reducing the dangers of totalitarian control.
See also 
- Collective consciousness
- Collective intelligence
- Complex Adaptive System
- Knowledge ecosystem
- Management cybernetics
- Noosphere (Teilhard de Chardin)
- Technological singularity
- Social organism
- World Brain (H.G. Wells)
- "Cyberspace: The Ultimate Complex Adaptive System". The International C2 Journal. Retrieved 25 August 2012. by Paul W. Phister Jr
- Heylighen, F., & Bollen, J. (1996). The World-Wide Web as a Super-Brain: from metaphor to model. In R. Trappl (Ed.), Cybernetics and Systems' 96. Austrian Society For Cybernetics. Retrieved from http://pespmc1.vub.ac.be/papers/WWW-Super-Brain.pdf
- Weinbaum, D. (2012). A Framework for Scalable Cognition: Propagation of challenges, towards the implementation of Global Brain models. GBI working paper 2012-02. Retrieved from http://pespmc1.vub.ac.be/ECCO/ECCO-Papers/Weaver-Attention.pdf
- Russell, P. (1983). The Global Brain: speculations on the evolutionary leap to planetary consciousness. Los Angeles: JP Tarcher.
- Andrews, D. (1986) Information routeing groups – Towards the global superbrain: or how to find out what you need to know rather than what you think you need to know, Journal of Information Technology, 1, 1, Feb, 22-35.
- Mayer-Kress, G., & Barczys, C. (1995). The global brain as an emergent structure from the Worldwide Computing Network, and its implications for modeling. The information society, 11(1), 1–27. Retrieved from http://www.ccsr.uiuc.edu/web/Techreports/1990-94/CCSR-94-22.pdf
- Bollen, J., & Heylighen, F. (1996). Algorithms for the self-organization of distributed, multi-user networks. Possible application to the future world wide web. In R. Trappl (Ed.), Cybernetics and Systems '96 (pp. 911–916). Austrian Society For Cybernetics. Retrieved from http://pespmc1.vub.ac.be/papers/AlgorithmsWeb.pdf
- Heylighen, F., 2011. Conceptions of a Global Brain: an historical review. In Evolution: Cosmic, Biological, and Social, eds. Grinin, L. E., Carneiro, R. L., Korotayev A. V., Spier F. Uchitel Publishing, pp. 274 – 289.
- Wheeler, William (1911) The Ant Colony as an Organism. Journal of Morphology 22:307-325, In: Stock, Gregory (1993) Metaman, p. 260
- Teilhard de Chardin, Pierre (1964) The Future of Man, Chap VII - The Planetisation of Man
- (Berners-Lee 1999, p4 and p41).
- Teilhard de Chardin, Pierre (1964) The Future of Man, Chap X - The Formation of the Noosphere
- (see Eörs Szathmáry and John Maynard Smith, Nature, 16 March 1995).
- Heylighen, F., 2008. Accelerating socio-technological evolution: from ephemeralization and stigmergy to the global brain. In: Globalization as evolutionary process: modeling global change. Routledge, p. 284.
- Tim O'Reilly: Towards a Global Brain (talk in 'One Great Idea' video series, March 2012).
- Chrystia Freeland: The advent of the global brain
- Bernstein, A., Klein, M., & Malone, T. W. (2012). Programming the Global Brain. Communications of the ACM, 55(5), 1.
- Rayward, W. B. (1999). H. G. Wells' s idea of a World Brain: A critical reassessment. Journal of the American Society for Information Science, 50(7), 557–573. Retrieved from http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.85.1010&rep=rep1&type=pdf
- Brooks, M. (2000, June 24). Global brain</a>. New Scientist, issue 2244, p. 22.
- Goertzel, B. (2002). Creating Internet Intelligence: Wild computing, distributed digital consciousness, and the emerging global brain. Kluwer Academic/Plenum Publishers. Retrieved from http://books.google.com/books/about/Creating_Internet_Intelligence.html?id=Vnzb-xLdvv8C&redir_esc=y
- Heylighen, F. (2007). The Global Superorganism: an evolutionary-cybernetic model of the emerging network society. Social Evolution & History, 6(1), 58–119. Retrieved from http://pespmc1.vub.ac.be/papers/Superorganism.pdf
- Heylighen, F. (2002). The global brain as a new utopia. Zukunftsfiguren. Suhrkamp, Frankurt. Retrieved from http://pespmc1.vub.ac.be/papers/GB-Utopia.pdf
Further reading 
- Wide audience
- Berners-Lee, Tim (1999) – Weaving the Web: The Original Design and Ultimate Destiny of the World Wide Web by its inventor. Texere, London.
- Bloom, Howard (2000) Global Brain: The Evolution of Mass Mind from the Big Bang to the 21st Century.
- Heylighen F. (2004): "Das Globale Gehirn als neue Utopia" (The Global Brain as a new Utopia), in: R. Maresch & F. Rötzer (eds.) Renaissance der Utopie (Suhrkamp, Frankfurt)
- Russell, Peter (1982) The Awakening Earth: The Global Brain London: Routledge & Kegan Paul. (emphasis on philosophy and consciousness)
- Stock, Gregory (1993) Metaman: The Merging of Humans and Machines into a Global Superorganism.
- de Rosnay, Joel (1999) "The Symbiotic Man: A new understanding of the organization of life and a vision of the future." McGraw-Hill Companies. (new sciences and technologies).
- S. Nambisan & M. Sawhney (2007): "The Global Brain" (emphasis on global innovation management)
- Advanced literature
- Bernstein, A., Klein, M., & Malone, T. W. (2012). Programming the Global Brain. Communications of the ACM, 55(5), 1.
- Goertzel, B. (2001) - Creating Internet Intelligence: Wild Computing, Distributed Digital Consciousness, and the Emerging Global Brain. Ed. Plenum.
- Teilhard de Chardin, Pierre (1964) The Future of Man (The classic on physical and psychological/mental development of global brain and global mind).
- Heylighen F. (2007): Accelerating Socio-Technological Evolution: from ephemeralization and stigmergy to the global brain, in: "Globalization as an Evolutionary Process: Modeling Global Change", edited by George Modelski, Tessaleno Devezas, and William Thompson, London: Routledge (ISBN 9780415773614), p. 286-335.
- Heylighen F. (2007): "The Global Superorganism: an evolutionary-cybernetic model of the emerging network society", Social Evolution & History. 6 No. 1,p. 58-119—a detailed exposition of the superorganism/global brain view of society, and an examination of the underlying evolutionary mechanisms, with applications to the on-going and future developments in a globalizing world 
- Heylighen, F. (2011). Conceptions of a Global Brain: an historical review. Evolution: Cosmic, Biological, and Social, eds. Grinin, L. E., Carneiro, R. L., Korotayev A. V., Spier F. (pp. 274 – 289). Uchitel Publishing.
- Mayer-Kress, G. and Barczys, C. 1995 - The global brain as an emergent structure from the worldwide computing network. The information society 11(1): 1-28. 
Fore more references, check the GBI bibliography: