Exploring the Science of Complexity: Ideas and Implications for Development and Humanitarian Efforts

Ben Ramalingam, Harry Jones et al.


What is complexity science? How can it contribute to development and humanitarian efforts? This paper explores the key concepts of complexity science and shows how they might help development practitioners engaged in reform. The concepts highlight that the best course of action will be context-dependent, and they offer new ways to think about questions that should be posed. Development practitioners need to recognise that they live with complexity on a daily basis, and to use the ‘complexity lens’.

The questions faced by aid agencies are perhaps the most complex facing humankind. There are a multitude of interactions within the various dimensions of economic and social development. International aid to address these issues takes place in the context of a globalised web of connections. Interactions among the elements of these different systems are themselves multifaceted, and aid relations run alongside many other kinds of international relations.

Despite this level of complexity, a reliance on simplistic models pervades the aid system. These oversimplify the systems being dealt with in developing countries and in the international aid system itself. Complexity science, by enhancing understanding of the mechanisms through which unpredictable, unknowable and emergent change happens, enables a reinterpretation of existing systems and the problems faced within them.

Complexity science is a loose network of interconnected and interdependent ideas that have helped to further understanding of the dynamics and processes of change found in physical and biological phenomena. It can help development practitioners to understand better the complexities of the real world. Its key concepts can be divided into three areas:

Complexity and systems:

  • Complex systems have interconnected and interdependent elements and multiple dimensions.
  • Both negative and positive feedback take place, which dampen or amplify change.
  • Emergent properties result from the interaction of the elements, which may be unpredictable, and these are not the properties of the individual elements themselves.

Complexity and change:

  • Relationships between dimensions are frequently nonlinear. Change is frequently disproportionate and unpredictable.
  • Small differences in the initial state of a system can lead to massive differences later.
  • Because of the challenges of analysing complex systems, a tool called phase space allows data to be mapped rather than solved. This enables understanding of how systems move and evolve over time.
  • Complexity, although seemingly disordered, shows order at the level of its trajectory. Although it may be unpredictable in its detail, it moves around a particular pattern.

Complexity and agency:

  • Individual people, teams and organisations are all adaptive agents reacting to the system and to each other. They may make decisions or develop strategies to influence each other or the overall system.
  • Self-organisation is where macro-scale patterns of behaviour occur as a result of the interactions of individuals who act according to their own goals.
  • The overall system and the agents within it evolve together, or co-evolve, over time.
  • Complex systems are difficult and costly to model and analyse, especially social, economic and political phenomena. But this needs to be balanced against the fact that linear cause-and-effect thinking may be useless.

The concepts of complexity can be used to highlight new possibilities for understanding development and humanitarian problems. Only when individuals and institutions working in international aid start consciously to use the complexity lens, however, will it become clear whether solutions to longstanding problems can be arrived at using complexity thinking. Meanwhile, the concepts of complexity can:

  • Be used in combination or individually, to augment existing models or frameworks or as a framework in their own right.
  • Help to explain why a particular change initiative was unsuccessful and be used for conceptualising and planning change initiatives.
  • Guide practitioners towards a more realistic understanding of the limitations of aid.
  • Provide a basis for understanding different aspects of ‘messy realities’ – aspects which may not otherwise be well understood or systematically investigated.
  • Be used to ensure that the principles for programme design or the principles of a change initiative take into account the notion and implications of complexity.

See also:


Ramalingam, B. and Jones, H. et al., 2008, 'Exploring the Science of Complexity: Ideas and Implications for Development and Humanitarian Efforts', Working Paper 285, Overseas Development Institute, London