What do we mean by complexity? How does complex differ from complicated? And what do we mean by simplicity? How do these concepts relate?
The notion of complexity appears in many subject areas, such as psychology and adult development, pedagogy, sociology, anthropology, economy, physics and biology. In order to bring some order I believe that a first distinction needs to be made, that between ontological complexity and epistemological complexity, and I’m not the first to do so. We could also refer to them as real and conceptual complexity, respectively.
Ontological complexity deals with the complexity of real things, real systems, real processes and organisms, such as the complexity of a tree, a colony of ants, an eco-system, an organization or a society. Here we find the classical complexity theories that emerged in the 50s and that is growing in popularity. Although there is no universal measure of how complex something is, the hallmark of high complexity is a high degree of differentiation and integration, i.e. many different parts and functions that work together to create a functioning whole.
A human body which is built up by atoms, molecules, proteins, cells, organs, etc., can be said to be very complex. And today’s society is often described as very complex since we have a great amount of different roles and functions that are coordinated in large organizations and entities. The various goods we ship across the world are very complex and requires the involvement of many parts and parties to be constructed. Today’s financial systems is also usually described as extremely complex in a negative sense in that it is impossible to overview and easy for crises to spread across the intimately interconnected and integrated world, as demonstrated in this TED talk. A computer manufacturer tried to track all components to ensure that all parts were produced in an ethical and sustainable manner, but they had to give up because there were so very many parties involved.
Epistemological complexity, in contrast, deals with the complexity in our thinking, i.e. the complexity in our ability to reason and the complexity of the problems we can solve. This is typically what we study in adult development and here we have a measure in the Model of hierarchical complexity, MHC, where we can say that a certain amount of information or a certain behavior can be evaluated at a certain stage of hierarchical complexity. Or the understanding that underlies a design principle. It is important to recognize that a certain level of epistemological complexity builds on and includes all previous levels of complexity.
Typically, I would say that the epistemological complexity is a pale shadow of the ontological, our understanding of the world is usually an insufficient and limited representation if it. Often, the most complex thing we can do is biomimetics, i.e. trying to mimic nature’s own complexity. But an important point here is to keep them apart. For instance, when we discuss the design of a city, a house or any artifact, we should distinguish between the two perspectives, the planned design and the actual design. Although there have been findings of fractal patterns in traditional sub-Saharan cities, it does not necessarily imply that those cultures understood the notion of fractals in a mathematical sense.
It is also important to recognize the similarities between the ontological and the epistemological complexities. The notion of differentiation and integration is commonly used to describe the process of increased complexity. Another key term is emergence, which means that that properties of the complex system as a whole can’t be explained by means of the parts or the interactions that build up the system. A number of ants can together perform complex tasks and create a complex colony without the individual ants to have the cognitive capacity for understanding what they are doing. The properties of a molecule can’t be predicted or explained by means of the properties of the atoms that go into it. Similarly, in MHC a foundational axiom is that a higher level or stage has to coordinate two or more parts or elements from a previous level in a non-arbitrary way so that a new and qualitatively different element is produced.
In ontological complexity, the distinction between complex and complicated is often emphasized. Complex refers to the characteristics that are explained in the above, while complicated is often associated with characteristics such as linearity and that can be reduced to its parts. A typical description is the following:
“… the main difference between complicated and complex systems is that with the former, one can usually predict outcomes by knowing the starting conditions. in a complex system, the same starting conditions can produce different outcomes, depending on interactions of the elements in the system.”
Complex problems are typically described as ill-structured or wicked, e.g. raising a child, when complicated systems are described as well-structured and solvable, although not easily, e.g. build a functioning car.
I would argue that complex in this sense corresponds to vertical complexity according to MHC in the epistemological case, and the complicated corresponds to horizontal complexity according to MHC. Horizontal complexity or development is usually described as “more of the same” or a quantitative increase in complexity, whereas vertical complexity or development means a qualitative shift or increase in complexity.
And finally for the simplistic part, for the epistemological simplicity I would like to offer an illustrating episode from the life of young Gauss. Perhaps one could find a correspondence for the ontological simplicity.