Emergence is a general term that refers to a characteristic of complex systems. Typically, emergence is the result of a process, where smaller ingredients act together to form a larger pattern. The resulting emergent properties tend to be very different from the properties of the smaller components. We have all heard it expressed in everyday language: “The whole is greater than the sum of its parts.” The quote has been credited to Aristotle.
So the idea is not new, and like many ideas it has been refined and expanded on over time. The concept of emergence has been applied to a wide range of behaviors and structures (both living and nonliving). It seems to happen everywhere, giving the impression that it’s a fundamental property of nature. Therefore, is it inevitable that complex interactions eventually lead to new phenomena?
An emergent property may be difficult to spot, because emergence is intertwined with our everyday world. At the scale of our experience the underlying causes for our observations are subtle and not always obvious. When something new or unexpected arises, and when order or organization comes about, it’s a good sign that emergence is involved.
Examples of Emergence
- Solids, Liquids and Gases: All the states of matter for a given compound, such as water, emerge from the same fundamental particles. The different properties of air, water and ice result from changes in the arrangement of the particles. In this case, temperature is the key factor for the phase transitions of water.
- Ocean Waves: Individual water molecules make up water droplets. A single droplet cannot make a wave, but countless droplets (with help from environmental conditions) can move together and create ocean waves.
- Ant Colonies: An ant has limited intelligence. The key to their evolutionary successes is their ability to work together. The communication and interconnections between the ants result in an overall intelligence of the colony, which far exceeds the intelligence of a single ant. Their survival needs can only be attained as a group.
- Flock of Birds: As birds fly in flocks they move about in patterns. The patterns are mesmerizing to watch as they constantly change. These patterns are surely unplanned and no single bird is in charge. The patterns emerge as a result of birds following simple rules. The flock is moving in a general direction, and each bird stays close to other birds, but far enough to avoid a collision.
- Movement of Crowds: Humans moving in crowds is an emergent property similar to the birds. No one is controlling the movement of people on city streets or gatherings at large events. Pedestrians are following each other and obeying general rules. Each person reacts to the people around them and their environment.
- Consciousness: This is perhaps the most impressive example of emergence. Although neuroscience has identified brain functions as the cause of consciousness, the mechanisms tell use very little about what consciousness actually is. Connections of neurons in the brain are physical processes, and yet we experience consciousness as nonphysical. And how does self-awareness emerge from processes that are not self-aware (as far as we know)?
Who or What is in Control?
With our human organizations we are accustomed to having a person or group in charge. It is a follow the leader mentality. This structure is rarely questioned, as it is the foundation of governments, religions, business entities and most organizations. We do, however, question the competency of the leaders at times. Nevertheless, the point is that nature operates differently. Most of the time, there is nothing in control; order and complexity emerges from the interactions of all the individual parts.
Generally, the emergent properties occur at the level we most identify with and experience. Broken down into its finer ingredients, the world around us is composed of different arrangements of atoms; all biology is controlled by the complex system of DNA and genes. Scientists have an extensive understanding of physics, chemistry and genetics, as well as many other specialized fields. Science can make progress by studying things in isolation; however, the behavior of the whole is still somewhat mysterious. Interactions of simple individual parts, lead to large-scale complexity and organization.
One of the fascinations with emergence is that the large-scale structures look nothing like the structures of the finer scales. And if one were to examine the ingredients, the net result would reveal a surprising outcome. Whether you look at the micro scale or the macro scale, emergence is counter intuitive. But it seems that nature is able to self-organize in multiple ways, without anyone or anything in control.
References: Systems Theory: 8 Emergence, Complexity Academy, Published on Mar 5, 2015, https://www.youtube.com/watch?v=pooxD8XF5Uw
NOVA science NOW: 34 – Emergence, aranial, Published on Aug 9, 2012, https://www.youtube.com/watch?v=aEaZHWXmbRw