Emergence is a relatively new scientific concept that is becoming an indispensable tool for understanding, explaining, and predicting a variety of complex systems - from biology to economics to robotics.

Examples of emergence include:

Schools of fish. As mentioned in the lesson, individual fish follow simple rules for swimming close to their neighbors. When enough fish join the group, the behavior of individual fish becomes eclipsed by the behavior of the school. As a school, fish are able to avoid predation and produce emergent group behaviors that would be impossible for any individual fish. For instance, this awesome video shows Sharks Trapped By A School Of Fish!

Economics. The economy of any society is complex - it’s hard to predict exactly how consumer habits, the confidence of banks to loan money, and resource availability will interact with each other to set the pace of the economy. This is why you often hear politicians arguing about whether they should try to control the economy or just “let market forces work.” Even money itself may eventually become decentralized with digital currencies like Bitcoin. For more, listen to NPR’s A Bet Over Bitcoin.

Robotics. If humans find something cool in nature, we have a hard time resisting the urge to build it for ourselves. We couldn’t let birds be the only animals to fly, fish the only animals to swim, and the stars to be the only things out of this world. Emergence is no exception. Engineers are now using concepts of emergence and self-organization to create sophisticated swarms of thousands of cheap, simple robots. Take a look at this video from Harvard, A Swarm of One Thousand Robots.

Putting Humpty Dumpty back together again

Complex systems are difficult to study because you can’t always explain how they work just by looking at the parts of the system. For example, you can take a car apart and figure out everything there is to know about how each piece operates, but at the end of the day you need to know how to put them back together in just the right way to make a working car. A system is not just the parts it’s made of, but also how these parts work together to achieve a greater goal.

The notion that you can’t fully explain something simply by taking it apart poses a challenging dilemma for many scientists. Scientific progress has brought us computers, modern medicine, and allowed us to go to the moon. This progress has come mostly by understanding things by taking them apart.  This approach to studying something by taking it apart is called reductionism. To understand the human body, you must first understand the cells it’s made of. To understand a cell, you must first understand the proteins, lipids, and other macromolecules it’s made of. To understand a macromolecule like a protein, you must first understand the binding properties of the atoms it’s made of. By taking things apart, you reveal important details about what a system is made out of.

In the brain, reductionism has provided us with exquisite details about the molecular machinery neurons use to communicate with one another. Despite this we still have no explanation for how neurons use their capacity to communicate with each other to produce our thoughts, perceptions, and cognitive abilities. It’s like the broken car- we know what all the parts are, but how exactly do they fit together to allow it to drive you somewhere?

To understand how a system operates as a single, cohesive entity requires a constructionist approach. Efforts to complement reductionism with alternative, constructionist approaches have led to exciting new ideas such as complexity theory and dynamic systems theory. These theories are now being applied to real world situations to help us understand systems in our brain, schools of fish, and social networks. You can listen to a great conversation about this in the Radiolab podcast on emergence.

If you still haven’t gotten enough emergence, below is a short list of interesting articles and books on the topic:

“More is different: Broken symmetry and the nature of the hierarchical structure of science” published in Science by Philip W Anderson in 1972.

“The emergence of patterning in life's origin and evolution” published by Robert Hazen in the International Journal of Developmental Biology in 2009.

“Patterns and mechanisms of schooling behavior in fish: a review” published by Dimitri Pavlov and Alexander Kasumyan in the Journal of Ichthyology in 2000.

“Complexity: A Guided Tour” a book written by Melanie Mitchell.
“Emergence: The Connected Lives of Ants, Brains, Cities, and Software” a book written by Steven Johnson.

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