2 Section readings – Complexity and chaos

Reading 5.1: Complexity and equifinality

We usually describe something that we have difficulty in understanding as ‘complex’. We label a lot of things around us as complex principally because we use inappropriate mental models to interpret the phenomena we are experiencing. Systems thinking is a good way of engaging with the world to understand apparently complex things.

There are two forms of complexity: ‘hard’ complexity, and ‘soft’ complexity. Hard complexity is when there are many interacting parts, creating a multitude of feedback relationships whose behaviour is difficult to predict. Soft complexity is simply when we don’t know enough about the situation, either because we have not had the resources to find out more about it, and/or because the very nature of the issue under investigation is intrinsically difficult to measure. In recent years, two distinct systems approaches to working with complex issues have arisen reflecting the hard/soft complexity divide. The hard systems approach is usually used by engineers, natural scientists and economists, and involves extensive collection of quantifiable data and subsequent analysis. The soft systems approach places great emphasis on exploring issues through participation with a mixed range of stakeholders. The information collected is mostly qualitative. This approach is usually used by social scientists, managers and information system developers. Increasingly, people are realising that most problems are a combination of hard and soft complexity, and therefore needed a blend of both approaches.

I have demonstrated how taking an analytical approach alone is inadequate in dealing with complexity. Breaking down the situation into distinct objects and studying them in increasing detail will not help you to understand how they will operate together as a ‘system’. A systems approach entails placing as much effort on identifying and understanding the connections between objects, as on identifying and understanding the objects themselves.

Living systems have a natural drive to evolve greater hard complexity. It may sound counter-intuitive, but the more interacting parts there are in a system, the more resistant it becomes to change, and the more resilient it is to disturbance. Remember that all living systems are striving to maintain homeostasis, a dynamic equilibrium through which the life of the system is maintained. Redundancy becomes important here – if systems have parts that can play the same role, then when one redundant part is knocked out, another complementary part can take its place. The most resilient and resistant systems are those that have a lot of diversity, both in terms of parts and interconnections.

Some of this resilience arises from an extremely odd phenomenon in the behaviour of many systems, which is called equifinality.

Equifinality relates to the observation that some systems always end up in the same state of dynamic equilibrium no matter what the starting conditions are. In practice, this means that many systems come to rest in a particular state, and if disturbed, return to that state.

The emergence of life on Earth and the development of a living Earth system may be an example of equifinality. No matter how often external conditions have changed to the extent that life on Earth is threatened, (e.g. a 30 per cent increase in the strength of solar radiation since life began, devastating asteroid impacts, ice ages that covered at least a third of the planet in ice, and now the human induced species extinction) life has continued to evolve and diversify.

The great diversity of species on Earth certainly gives the Earth system considerable resilience. This may explain why continuing human-induced species extinction has not yet resulted in any significant changes in major feedback processes, such as the carbon cycle. In systems terms, it may therefore not be as useful to focus on species extinctions, but rather, a focus on functional types (groups of species that perform the same role within feedback cycles) may tell us more on whether the Earth system’s resilience is imminently threatened. This applies to systems thinking more generally – one way of tackling a complex situation is to avoid wasting too much time on the detail of individual components, but to focus on identifying functional groups. For example, significant advances in modelling the impact of climate change on various ecosystems around the world has been achieved by forgetting about how each individual species would react, but instead grouping the species into similar life strategies. In other words, species are grouped together if they have similar food and habitat requirements. The extinction of one of these species may therefore not have an impact on the functioning of an ecosystem if similar species are also present. On the other hand, if a species fulfils a unique role within an ecosystem, and this species becomes extinct, then the ecosystem may very well collapse.