Complexity International
    ISSN 1320-0682     
Volume 4 1997
 

 

Use of Fuzzy Logic when Dealing with Social Complexity

Vladimir Dimitrov
School of Social Ecology
University of Western Sydney - Hawkesbury,
Richmond 2753, Australia
Fax: +61(45) 701531
Phone: +61(45) 701903
Email: V.Dimitrov@uws.edu.au

Abstract

This study is about working with social complexity. Fuzzy logic helps in describing, analysing, understanding and eventually working with paradoxical and chaotic nature of social systems. Research results related to a study of a fuzzy logic-based consensus-seeking enterprise are discussed in detail. What is crucial for such an enterprise is the mutual acceptance of one another such as we are. Any act of acceptance of the other is preceded by a kind of OEfuzzificationà of some separating boundaries; this allows people to act together.

1 Introduction

Fuzzy set theory, or fuzzy logic, first proposed by Zadeh in 1965 (Zadeh), represents an attempt to construct a conceptual framework for the systemic treatment of vagueness and uncertainty both qualitatively and quantitatively (see Appendix). In the social sciences, fuzzy logic was first applied to the problem of social choice and self organisation in the early 1970's (Dimitrov 1970, Barnev et al., Dimitrov et al., Dimitrov 1976, Dimitrov 1983).

The application of fuzzy logic to social systems creates opportunities to examine:

Fuzzy logic is suited to studying such 'subtleties' in social systems because of its ability to:

Fuzzy logic provides an alternative way of understanding uncertainty. From this new way of understanding can be derived innovative approaches and strategies for working with the uncertainty that so often characterises social systems.

2 Paradoxical and chaotic nature of social complexity

Human concepts, opinions, judgements and expectations change and evolve in the dynamics of social complexity. This complexity appears paradoxical and chaotic.

Why is social complexity paradoxical? Because it is the source of many contradictory and opposing forces acting together and, at the same time, the product of the forces. Any attempt to unravel these forces create a circular process that can paralyse further individual or social actions.

The more the members of a group seek to pull the contradictions apart, to separate them so that they will not be experienced as contradictory, the more enmeshed they become in the self-referential binds of paradox' (Smith et al.).

To manage social complexity means to manage its inherent paradoxes and their effects avoiding the danger of double bind paralysis.

Why is social complexity chaotic? The dynamics of social complexity are chaotic in the sense that the aggregate fluctuations of any complex social process (or behaviour) represent an endogenous phenomenon that persists even in the absence of 'stochastic shocks'. The emergence of complex irregular behaviour depends on both the initial conditions under which the process dynamics evolve and the critical values of the parameters characterising this evolvement.

Every time we deal with mathematical representations of social reality as a whole, we deal with chaos. Closed social systems are dissipative; their dynamics are described by strange attractors (Goerner). Open social systems are symplectic (Dimitrov 1994); their dynamics are chaotic without the occurrence of strange attractors.

Emergent phenomena are typical of the dynamics of complexity. In social systems, emergent phenomena manifest themselves any time when collective behaviour transcends the behaviour of its 'components' behaviour; because it transcends individual behaviour, it cannot be 'in' it before the emergence takes place.

To manage social complexity means to manage its chaotic dynamics as well as its effects, thus avoiding the danger of destruction and collapse.

3 The role of Fuzzy Logic in managing social complexity

With Fuzzy Logic we can describe, analyse, understand and eventually manage the paradoxical and chaotic nature of complexity.

3.1 How does Fuzzy Logic help deal with social paradoxes?

Simply by tolerating opposites, by balancing them to such degrees that they cease to cancel each other out and become complementary. With Fuzzy Logic we can create an imprecise and easy-to-reshape-and-modify framework in which the 'either/or' approach to the contradictory concepts expressed in the paradox is replaced by a 'both/and' relationship of their parallel acceptance. For example, a fuzzy framework created in the management practice can meaningfully transform expressions like 'collaboration OR competitiveness' into 'collaboration AND competitiveness', 're-organisation OR stability' into 're-organisation AND stability'.

For example, let us consider the 'independency paradox': it is only when social dependencies are established that the interdependence emerges, and it is this collective interdependence (between people, and between people and their environment) that provides the notion of individual independence with meaning. This paradox becomes easily manageable any time we apply the following fuzzy rule:

IF there is interdependence between A and B, AND their relationship is one of a high enough degree of trust, mutual understanding and tolerance THEN both A and B are able to act quite independently.

Another example is the 'difference-similarities' paradox: while differences in interests and values are important for the survival of any human system, they have meaning only because of the similarities that also exist and provide a basis for any collective endeavour. This paradox can be handled if both similarities and differences are balanced by fuzzy logic in a way that excludes too much emphasis on them. When a suitable fuzzy framework is created, differences between people and the viewpoints they represent become complementary and necessary to one another, instead of being contradictory and opposite. In this way, the difference-similarity paradox simply is dissolved. One can find many examples of this transformation in the practice of negotiation.

3.2 How does Fuzzy Logic help deal with chaotic patterns of behaviour in social systems?

Fuzzy Logic helps deal with chaotic patterns of behaviour in social systems by generating fuzzy rules (heuristics) which focus on the local, the decentred and the marginal in social behaviour. Often what is excluded, what is not seen in the patterns, 'what is not there' becomes important in constructing a list of fuzzy rules to describe and grasp 'what is there', what is in the core of the system, what makes the system chaotic.

A chaotic social reality paradoxically seems to unite people in a common desire to be different, unique and creative. Plural descriptions, open for change, based on people's personal experience and shared through dialogue, or derived by collaborative inquiry, are meaningful in such reality - they help to disclose the tensions in it, not to resolve them but to examine the contradictions and inconsistencies and, by the same token, to reveal the conditions which could trigger the emergence of some kind of order (transitory though it usually is) in social systems.

The principle of non-exclusion and non-isolation is fundamental for the use of fuzzy logic in any turbulent social (or socio-ecological) environment. Non-exclusion means that no options or alternative (however improbable it seems to be for inclusion in the future scenarios), should be excluded from consideration; it might turn out to be of crucial significance for the survival of society and its environment. Non-isolation means that chaotic behaviour does not privilege any economic optimality: to isolate only one option, alternative or strategy by describing it as the best, the optimal or the most efficient, from whatever point of view, is senseless; turbulent dynamics do not tolerate any pre-imposed isolation however 'optimal' it may appear to the decision-maker.

The paradoxical and chaotic nature of social reality causes a great deal of uncertainty and vagueness in human decision-making. Under conditions of uncertainty and vagueness, when no ultimate answers or best solutions exist, the search for understanding and consensus between people becomes crucial for the management of social complexity.

4 Fuzzy Logic in action: a consensus-seeking enterprise

In the turbidity of human interactions, consensus ceases to be a peaceful long-term commonality of stakeholders' interests. Such commonality grows on 'determinacy' and stability. Unfortunately, neither 'determinacy' nor stability are features of social reality. The more we reach for commonality in human interactions, the farther away it seems to be. 'Consensus is a horizon that is never reached' (Lyotard).

An irreducible indeterminacy constantly emerges when we explore more deeply both variety and uncertainty of group decision-making. Paradoxically, instead of consensus being the power house of common social action, it is 'dissensus' which operates in consensus seeking enterprise, permanently implanting chaotic vibrations in the process of communication.

However, the chaos does not cause the communication network to dissipate. Rather, it eventually gives birth to an emerging order in the form of a new type of dynamic consensus between stakeholders: consensus for seeking a consensus.

4.1 Second Order Consensus

This can be defined as 'second order consensus' - people 'agree to disagree' or 'disagree to agree'. They seek consensus by exploring different ways that might lead to mutual understanding and preparedness to move together, to make the next step into the fuzziness of common expectations.

It does not matter that consensus in our society is 'condemned' to be momentary and transient - what can endure in time is human anticipation and aspiration, the impulse to act together, the natural desire to interact and communicate, to share with and care for others. In other words, not only a search for common actualisation of meaning but strong emotional factors (sharing and caring) catalyse the emergence of second-order consensus out of the chaos of dissent and disagreement, contradictions and conflict.

Consensus-seeking differs from consensus-building. When seeking consensus, stakeholders do not necessarily look for a 'common ground' in the form of full agreement. On the contrary, they underline and study the differences between them, trying to understand social mechanisms which make stakeholders differ in their interests, values, goals, etc. No constraints on stakeholders' views and opinions, no changes of their values and beliefs are required as preliminary conditions for seeking a consensus.

The process is entirely open for emergence of new features and unpredictable situations - spontaneity is an important characteristic of this process. No preliminarily assigned goals exist - pre-imposed goals, constraints or requirements can narrow the scope of the stakeholders' search.

The search for consensus is motivated by the stakeholders' drive to be mutually complementary in their efforts to more fully understand the complexity of the issues and of their concern to find out how to act together in order to benefit from the differences in their knowledge. While conducting their inquiry, the stakeholders are aware of the irreducible fuzziness and uncertainty of this knowledge, yet they agree to explore it together and construct it anew. Thus, a second order, dynamic-type consensus emerges. This kind of consensus is not simply an overlap of stakeholders' interests, values, goals, positions, views.

Second order consensus means that there is a shared acknowledgement that there are diverse, changing and only partially shared views about complexity among the stakeholders, that it is full of zones of uncertainty ('value-dark zones') in which neither the causes nor the effects of what occurs is clear or even can be known. Also, there is an agreement to explore the complexity together in order to arrive at a better understanding of it by using not only your own but each other's experience, expertise and ideas, and, through this better understanding, arrived at an improved preparedness to act together; that is, to engage in joint, collaborative action to manage the complexity.

What occurs in the zones of uncertainty is at least in part influenced by the joint action of the participants (stakeholders), and so the complexity is being partly made by them. On the other hand, as the complexity evolves in time, it also exerts an influence on the stakeholders, and triggers them to reconstruct their views. What the new complex situation will be contains both intentional and unintentional elements as the participants in the joint action coordinate their activities and respond to each other's constructions of the reality of the situation and to each other's actions in it (Maturana, Turner).

4.2 Preparedness to act together

Stakeholder's preparedness to act together (that is, 'consensus for seeking a consensus') can be expressed as a fuzzy composition of three major components:

  1. The willingness to engage in dialogue (both to listen and to converse) implies willingness to acknowledge the validity of different statements or positions (on an issue of stakeholders' concern) - not closure in a pre-defined rigid conceptual framework but search for a fuzzy logic-based context where stakeholders' intentions and anticipations have fuzzy, easily changeable formulations - able to be re-shaped, to move into opposites, to be set aside or to grow within a tree-like prolific structure.

    What matters in the streamline of the dialogue is stakeholders' willingness to keep moving together - to explore options for consensus, to share knowledge and experience, to learn together how to create and implement group decisions when tolerating, appreciating and even 'celebrating' the differences in people's thoughts and actions.

  2. The second, the trustworthiness is renewed in acting together; it ceases to be a derivative of the past only and appears as a property of stakeholders' involvement in collaborative activity, based on their shared responsibility and accountability.

  3. The third, the creative urge (creativity), is a psychological process that involves innovative use of fresh ideas and new formulations (including use of metaphors, metaphorical imagery, metonymy, synecdoche, paradoxes, humour, jokes, story telling, etc.) helping stakeholders not only to enrich and extend variety of their potential options for consent, but also to discern the sense of being in a group, the sense of 'moving' and acting together in a world where relativity, complexity and uncertainty are inevitable companions.

In the free flow of unanchored, constantly changing and shifting individual values, beliefs and expectations, the higher the degree of willingness for dialogue, trustworthiness and creativity as expressed by a group of stakeholders, the higher their preparedness to act together.

Fuzzy Logic helps to transform the group profiles of the above consensus-seeking parameters into characteristics of stakeholders' preparedness to take actions together. Practically, this help is realised by means of properly chosen fuzzy logic rules.

4.3 Fuzzy Rules

The general form of the fuzzy rules used in a consensus-seeking enterprice is:

IF W AND T AND C, THEN PAT

where W, T, C and PAT denote the following fuzzy classes:

W: Willingness to engage in dialogue

T: Trustworthiness

C: Creativity

PAT: Preparedness to Act Together.

Each fuzzy class is described using the following three lingustic variables:

L: low

M: moderate

H: high

It is assumed that in consensus-seeking practice, the values of the membership functions (see Appendix) to the above fuzzy classes, characterised by the linguistic variables 'low', 'moderate' and 'high', can be assigned by a facilitator who participates (observes, facilitates, helps) in negotiation between stakeholders.

The following fuzzy rules have been used in a software product called FLOCK (Fuzzy Logic-based Consensus Knowledge) (Dimitrov & Kopra), specially designed to help facilitators in practical realisation of the idea of second order consensus:

  1. IF two of the three fuzzy classes W, T, C are simultaneously characterised by one and the same linguistic variable which is not equal to 'moderate', THEN PAT is described also by the same variable, no matter what is the linguistic variable characterising the third class.

    Example:

    IF both W AND T = 'low' OR 'high', THEN PAT = 'low' OR 'high', respectively.

    IF both W AND C = 'low' OR 'high', THEN PAT = 'low' OR 'high', respectively.

    IF both T AND C = 'low' OR 'high', THEN PAT = 'low' OR 'high', respectively.

  2. IF two of the three fuzzy classes W, T, C are simultaneously characterised by one and the same linguistic variable which is equal to 'moderate', THEN PAT is described by the linguistic variable characterising the third class.

    Example:

    IF both W AND T = 'moderate' AND C = 'high' OR 'low' OR 'moderate',

    THEN PAT = 'high' OR 'low' OR 'moderate', respectively.

    IF both W AND C = 'moderate' AND T = 'low' OR 'high' OR 'moderate',

    THEN PAT = 'low' OR 'high' OR 'moderate', respectively.

    IF both T AND C = 'moderate' AND W = 'high' OR 'low' OR 'moderate',

    THEN PAT = 'high' OR 'low' OR 'moderate', respectively.

  3. IF the three fuzzy classes W, T, C are characterised by different (not coinciding) linguistic variables, THEN PAT is equal to 'moderate'.

    Example:

    IF W = 'low' AND T = 'moderate' AND C = 'high', THEN PAT = 'moderate'

    IF W = 'high' AND T = 'low' AND C = 'moderate', THEN PAT = 'moderate'

    IF W = 'low' AND T = 'high' AND C = 'moderate', THEN PAT = 'moderate'

    IF W = 'moderate' AND T = 'low' AND C = 'high', THEN PAT = 'moderate'

    IF W = 'high' AND T = 'moderate' AND C = 'low', THEN PAT = 'moderate'

    IF W = 'moderate' AND T = 'high' AND C = 'low', THEN PAT = 'moderate'

    4.4 What does it mean to be 'in common'?

    Fuzzy logic offers a framework for understanding the oscillating between phenomena of disaggregation and communion in society. For to be 'in common', it does not matter much what our social status is (politician, businessperson, factory worker, farmer, academic) - what matters is the mutual acceptance of one another such as we are. According to Agamben (Agamben), the 'others' matter to us not because we are attracted by their specific characteristics (succesful, rich, clever, influencial) nor because we identify them with some favoured social formation, but because we are appreciative of them with all of their traits such as they are, warts and all. We cannot seek consensus without accepting each other as we are.

    In the context of fuzzy logic, such an actualisation of the meaning of 'being in community' makes sense and helps when dealing with the forces of social disintegration. Any act of acceptance of the other is preceded by some kind of fuzzification of any separating boundaries; this allows people to act together. Neither government nor business can function without accepting the rest of society as it is. Economic, social and political systems should be seen as evolving interrelated networks within society, and not as separated systems. National and global survival of humanity crucially depends on social integrity.

    5 Understanding dynamics of social complexity

    Social complexity is in permanent change - the intensity and direction of this change is beyond the ability of researchers and society itself to predict and control.

    Chaos theory applied to social systems builds a general picture of society as being constituted by interactive 'fuzzy dynamics' giving rise to a range of emerging types of social behaviour (Goerner).

    We observe that a multitude of transient equilibria emerge in social dynamics, that there is a constant evocation of increasingly complex forms of order in evolving systems in the life of the society, and that spontaneity is inherent in the temporality of this life. All of these effects are a manifestation of what we term 'the divergence syndrome' (Dimitrov et al.1996) where dramatic social changes can emerge as a result of seemingly insignificant socio-political actions. The divergence syndrome describes the 'self-feeding' acceleration of energy flow that takes place in social systems.

    The world remember that 'small' change in the ruling politburo of the former Soviet Union in the mid-eighties, when Gorbachev was appointed as a Secretary-General of the Soviet communist party; the effects were shocking.

    Another socio-political illustration of the divergence syndrome: slight changes in the ideological platform of a political party or a politician, expressed by means of seemingly insignificant fuzzy hedges (that is, words used in statements or narratives to intensify or dilute the fuzzy set's membership functions or to change the degree of fuzziness in a fuzzy set, such as: 'more or less', 'very', 'quite', 'somewhat', 'slightly', 'extremely', 'positively', 'generally', 'around', 'about', 'near', etc.) can bring forth enormous changes in their interpretation as a basis for action. For example, during an election campaign, politicians can promise 'to keep the defence potential of the state at a more or less stable level', but once in power, they can use this statement as justification of a large program for testing new nuclear weapons with enormous negative consequences for people and environment.

    6 Conclusion

    To understand and manage social complexity means to develop an ability for managing: (a) the paradoxes inherent in social systems and their effects, thus avoiding the danger of double bind paralysis, and (b) the chaotic dynamics of social life as well as the effects of these dynamics, thus avoiding the danger of destruction and collapse.

    Fuzzy logic helps in describing, analysing, understanding and eventually dealing with the paradoxical and chaotic dynamics of social systems.

    Fuzzy logic also offers a useful framework for understanding the oscillations between disaggregation and communion in society: what matters in a 'healthy community' is the mutual acceptance of people such as they are. This is the starting point for any consensus seeking process.

    Acknowledgements

    The author would like to thank his colleagues Dr Robert Woog, Ms Lesley Kuhn-White and Mr Kalevi Kopra for helpful and inspiring dicussions on different aspects of social complexity.

    Appendix

    What is Fuzzy Logic?

    Fuzzy Logic is a method for understanding, quantifying and dealing with vague, ambiguous and uncertain characteristics, ideas and judgements. Basic notion in Fuzzy Logic is the notion of fuzzy set (fuzzy class).

    A fuzzy set (class) A is characterised by the membership function m (A), which takes values in the interval [0,1], that is, m(A): U-> [0,1], where U is a universe of discourse in which A is defined (Zadeh, 1965).

    For example, if the universe of discourse U includes all proposals (ideas, statements) generated by a group of stakeholders participating in a consensus-seeking enterprise in response to the question: 'How to move out of the present state of standstill in negotiation?', then the fuzzy class of stakeholders' creativity can be described using a membership function equal to 0 for stakeholder(s) unable to produce any single proposal, and then increasing to 1 towards stakeholder(s) with maximum number of proposals (say 10).

    The fuzzy class can be characterised by a linguistic variable corresponding to a set of values of the membership function. In the above example, if the ideas generated by each stakeholder varies from 0 to 10, then the 'creativity' of stakeholder A with only one proposed idea can be characterised by the linguistic variable 'low', while the creativity of stakeholder B with 8 generated ideas can be characterised by the linguistic variable 'high'.

    The linguistic variables have fuzzy boundaries; that is, two 'neighbour' variables always have a 'non-zero overlap'. In the above example, if stakehoders C and D offer 4 proposals each, their creativity can be considered both as 'medium' (or 'moderate') with a degree of membership, say 0.8 and 'low' with degree of membership, say 0.3. This occurs because the neighbour linguistic variables 'low' and 'medium' has a non-zero overlap. In the software facilitation tool FLOCK mentioned in the paper, the facilitator assigns the values of the linguistic variables at each stage of the negotiation process.

    Fuzzy logic helps us to quantify also the degree of truth of a fuzzy statement (a 'fuzzy statement' is a statement which contains linguistic variables). The standard definitions in Fuzzy Logic are:

    where x and y represent some fuzzy statements.

    For example, if the degree of truth of the statement x = 'Creativity of stakeholder A is low' is 0.9, then the degree of truth of the statement NOT x = 'Creativity of stakeholder A is NOT low' will be 0.1; that is, 1.0 - 0.9 = 0.1. If the degree of truth of the statement y = 'Creativity of stakeholder B is high' is 0.9, and the degree of truth of the statement z = 'Stakeholder B's willingness to participate in dialogue is high' is 0.6, then the degree of truth of the statement (y AND z) = 'Stakeholder B is with high creativity AND his(her) willingness to participate in dialogue is also high' = min(0.9, 0.6) = 0.6.

    Fuzzy Rules are of the form IF... THEN..., where both IF and THEN terms are natural language expressions of some fuzzy classes or their combinations. Fuzzy Logic provides powerful computational techniques for manipulations with these classes aimed at specific problem-solving. More about Fuzzy Rules, their application and frequently asked questions about Fuzzy Logic can be found at http://www.cac .usl.edu/~manaris/ai-education-repository/fuzzy-resources.html.

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    Complexity International (1997) 4