If we don’t first know “what is system is”, how do we approach an intervention? #MichaelCJackson OBE and Dr. #LuisGSambo appreciate the difference between “systems thinking” (plural) and “system dynamics” (singular), and suggest expanding theory with Critical #SystemThinking in Health Systems Research.
An ignorance of history is, if anything, even more pronounced among those authors in [Health Systems Research] influenced by complexity theory and the concept of ‘complex adaptive systems’. [….]
Most authors employing complexity theory in HSR seem to believe that it sprung forth fully formed from nothing or has somehow supplanted other bodies of work in systems thinking.
Such a poor appreciation of the history makes it almost inevitable that HSR will draw upon a restricted part of the systems and complexity tradition in developing its theories. In fact, it is the system dynamics and ‘complex adaptive systems’ strands that have come to dominate HSR at the expense of others. [….]
The problems start because of a lack of clarity in HSR about what type of ‘dynamic entity’, or ‘system’, a health system is. [….]
[Critical Systems Thinking] takes a radically different approach to HSR in the way it responds to the complexity encountered in the health systems domain. Primarily, HSR designates health systems as ‘complex adaptive systems’, and then looks to system dynamics to provide knowledge of their inner workings and supply insights into how they can best be managed. [….]
CST by contrast regards ‘messes’, like those found in public health, as ‘unknowable’. They give rise to what Rittel and Webber call ‘wicked problems’, which are intractable for decision-makers … [….]
CST, therefore, bypasses the issue of what kind of ‘system’ a health system is by stating that we will never know. Far from being a negative strategy, however, this opens up a whole new realm of possibilities, …
CST can assist … by referring to the three commitments of CST – ‘critical awareness’, ‘pluralism’, and ‘improvement’.
Source: Jackson, Michael C. & Sambo, Luis G. (2019). Health systems research and critical systems thinking: the case for partnership. 10.13140/RG.2.2.36160.48648.
In deciphering Yin-Yang and Five Elements (Five Phases) thinking, #Kaptchuk (1983) has a footnote and then an appendix that clarifies the way forward for appreciating foundations of Chinese medicine favouring the former. For philosophical correctness, Keekok Lee (2017) would frame the Chinese implicit logic as dyadic, rather than as a Western explicit logic of dialectic.
Yin (陰) and Yang (陽) Theory
The logic underlying Chinese medical theory — a logic which assumes that apart can be understood only in relation to the whole — can also be called synthetic or dialectical. In Chinese early naturalist and Taoist thought, this dialectical logic that explains relationships, pattern and change is called Yin-Yang theory. [†† ]
Kaptchuk (1983), p. 7
[††] Although the Chinese identify the relationships between phenomena primarily by the patterns of Yin and Yang, another system of categorization, known as the Five Phases, was also in use in early China. In this system, Wood, Fire, Earth, Metal and Water were seen as a set of emblems by which all things and events in the universe could be organized. Although the Five Phases categories permeate virtually every aspect of the traditional thought, leaving a significant impression on Chinese medical theory, this influence is for the most part formal and linguistic in nature. The Five Phases proved too mechanical, while Yin-Yang theory, because of its greater flexibility, was much for practical for the Chinese physician. It accommodated clinical changes and theoretical development that the tradition required in order to grow. (For a detailed discussion of the Five Phases in Chinese medicine, see Appendix H).
This important footnote seems to NOT show up the eBook versions for later editions that I’ve seen on the web (or maybe the previews are just incomplete).
Let’s jump down to Appendix H: The Five Phases (Wu Xing), with the note: This appendix was written in collaboration with Dan Bensky and the assistance of Kiiko Matsumoto. (We’ll skip over the preliminary Five Phases description, to get to discrepancies with Yin-Yang Theory).
The number five was important in the numerology of the period, particularly in for classifications of Earthly things. Various other numbers, such as six, four, and three, turn up in early classification schemes for things pertaining to Heaven. It is difficult to determine whether the importance of the number five led to Five Phases theory or the popularity of the Five Phases theory led to things being classified in fives.
Kaptchuk (1983), p. 346
 Jia De-dao, Concise History, pp. 29-30. For example, Lu’s Spring and Autumn Annals (246-237 B.C.E.) mentions Four Phases, omitting Earth.
During the third and fourth centuries B.C.E., the Five Phases theory and the Yin-Yang theory existed simultaneously and independently of each other. For example, Lao Tzu and Chuang Tzu refer extensively to Yin and Yang but do not mention the Five Phases. Unlike other traditional cultures with systems of elemental correspondences (e.g. the Greek Four Elements or the Hindu Three Doshas), the Chinese thus had two systems of referents. It was not until the Han dynasty, a period of great eclecticism and synthesis, that the two systems began in merge in Chinese medicine. “The five elements [Phases][which] had not been part of the most ancient Chinese medical speculations” were incorporated into the clinical tradition that culminated in the Nei Jing. Certain parts of the Nei Jing refer to the Five Phases, whlle others do not. Yet other texts, such as the Discussion of Cold-Induced Disorders and the biography of Bian Que in the Shi Ji or Historical Records, make no mention whatsoever of Five Phases theory. The Five Phases theory continued to undergo changes even after its incorporation into Chinese medicine. It is not until the Song dynasty (96-1279 C.E.) that the relationships between the Phases were commonly used to explain the etiology and processes of illness.
Kaptchuk (1983), p. 346
 Fung Yu-lan, History of Chinese Philosophy, vol 1, p. 8; Chan, Chinese Philosophy, p. 224; Hans Agren, “Patterns of Traditional and Modernization in Contemporary Chinese Medicine,” in Medicine in Chinese Cultures: Comparative Studies of Health Care in Chinese and other Societies, ed. by Arthur Kleinman, et al. (Washington, D.C.: John E. Fogarty International Center, U.s. Dept. of HEW, NIH, 1975), p. 38
 Lu Gwei-djen and Joseph Needham, “Records of Diseases in Ancient China,” American Journal of Chinese Medicine 4, no. 1 (1976): 12.
 Dan Bensky, “The Biography of Bian Que in the Shi Ji,” unpublished manuscript, University of Michigan, 1978, p. 2.
 Recent archeological discoveries of pre-Nei Jing texts confirm the impression that Yin-Yang was originally a much more important port of Chinese medicine than the Five Phases theory. See “A Simple Introduction to Four Ancient Lost Medical Texts Found at the Tomb of Ma-wang,” Medical History Text Research Group of the Academy of Traditional Medicine, Wen Wu, no. 6 (1975), pp. 16-19. The Five Phases are not mentioned in these ancient medical writings. See Chapter 4, Note 3.
 Jia De-dao, Concise History, pp. 165-166.
Many attempts were made to fit the Five Phases neatly into the Yin-Yang structure. For example, Wood and Fire were considered the Yang Phases, being active in character, while Metal and Water, associated with quiescent functions, were the Yin Phases. Earth was the balance point between Yin and Yang, despite this apparently successful marriage between Five Phases and Ying-Yang theory, the two systems of correspondence frequently yielded different interpretations of health and disease 
For example, Five Phases theory might emphasize the following correspondences stated in the Nei Jing: The Liver opens into the eyes; the Kidney opens into the ears; the Heart opens into the tongue. Disorder in a particular orifice would necessarily be linked into is corresponding Organ.
Yin-Yang theory, on the other hand, might emphasize the the following quite different assertions of the Nei Jing: The pure Qi of all Organs is reflected in the eyes; all the Meridians meet in the ears; the tongue is connected to most of the Meridians. Yin-Yang theory would not necessarily see a link between a part and a part. Rather, all disharmonies of the eyes, ears or tongue would be interpreted in terms of patterns. Thus, an eye disorder could be part of a Liver disharmony or perhaps a Lung or Spleen disharmony, depending on the configuration of other signs.
The differences between these medical interpretations stem from the fact that Five Phases theory emphasizes one-to-one correspondences, while Yin-Yang theory emphasizes the need to understand the overall configuration upon which the part depends. And so, although Five Phases theory is ideologically more dynamic than, for instance, the Greek or Hindu systems, and is actually being applied creatively to medical practice, it became a rigid system. Yin-Yang theory, on the other hand, with its emphasis on change and view of the importance of the whole, allowed for a great deal of flexibility. It was therefore easier to adapt to the needs of clinical practice.
Kaptchuk (1983), p. 346-347, editoral paragraphing added.
 Porket, Theoretical Foundations, p. 118. “Traditional Chinese thought has a general tendency to reconcile and harmonize different or even mutually exclusive ideas in an arbitrary syncretism. Contrary doctrines — for instance, Nakamura’s discussion of this Chinese characteristic states: “What stand out in this sort of reasoning is a certain sort of utilitarianism and early compromise with cold logical considerations completely abandoned.” Hajime Nakamura, Ways of Thinking of Eastern Peoples (Honolulu, East-West Center Press, 1968), p. 291.
In that last paragraph, “Yin-Yang theory emphasizes the need to understand the overall configuration upon which the part depends” could be interpreted either as a systems approach, or as a context for the dyadic. Five Phases theory appreciates part-part interactions, but may miss the whole (that is foundational to systems thinking).
Chinese medicine has had to take many liberties with the Five Phases theory to fit it to actual medical experience. The physiology that grew out of Five Phases theory, for example, is not identical with traditional Chinese physiology. The tradition is based on empirical observation and is ultimately connected to Yin-Yang theory, concentrating on the functions of the Organs and extrapolating their interrelationships from their functions. The Organs are thus the key to the system. Five Phases theory does not always agree with this understanding, and in that case, it is simply ignored. For example, in Five Phases physiology, the Heart corresponds to Fire. Traditional texts, however, consider the Kidneys (Life Gate Fire) to be the physiological basis for the Fire (Yang) of the other Organs. And so, the Five theory’s formal correspondence would be conveniently forgotten.
Kaptchuk (1983), p. 347
 Qin Bo-wei, Medical Lecture Notes , pp. 15-22.
We’ll skip over the “Use of the Five Phases in Medicine” (pp. 347-351), towards favouring Yin-Yang theory.
Criticism of Five Phases Theory
The Five Phases theory has been the subject of criticism ever since its invention. The challenges to its veracity and practicality date as far back as Mohist contemporaries of Zou Yen (fourth century B.C.E.). For example, one comment on the Mutual Control order reads: “Quite apart (from any cycle) Fire melts Metal, if there is enough Fire. Or Metal may pulverize a burning fire, if there is enough Metal. Metal will store Water (but does not produce it). Fire attaches itself to Wood (but is not produced from it).”
Kaptchuk (1983), p. 351
 Quoted in Needham, Science and Civilization, vol. 2, pp. 259-260.
A few hundred years later, the great Han dynasty scientist and skeptic Wang Cong satirized the results of literal application of the Five Phases theory. Here are two short excerpts from his work:
Kaptchuk (1983), p. 351
The body of a man harbors the Qi of the Five Phases, and therefore (so it is said) he practices the Five Virtues, which are the Tao (Way) of the Phases. So long as he has the five inner Organs within his body, the Qi of the Five Phases are in order. Yet according to the theory, animals prey upon and destroy one another because they embody the several Qi of the Five Phases; therefore the body of a man with the five inner Organs within it ought to be the scene of internecine strife, and the heart of a man living a righteous life be lacerated with discord. But where is there any proof that the Phases do fight and harm each other, or that animals overcome one another in accordance with this?
The horse is connected with the sign wu (Fire); the rat with sign zi (Water). If Water really controls Fire, (it would be more convincing if) rats normally attacked horses and drove them away.
Wang Cong, cited in Kaptchuk (1983), p. 352
 Ibid., pp. 265-266. Translation altered by author.
Despite such early criticism, the Five Phases theory became entrenced in Chinese medicine. One reason for this is that Chinese investigative study tends to be inductive only to a point and then proceeds with deductions based on classics. The Five Phases theory thus served as an orthodox reference for numerous speculative deductions.. Most modern Chinese critics describe Five Phases theory as a rigid metaphysical overlay on the practical and and flexible observations of Chinese medicine.
Kaptchuk (1983), p. 352
 Nakamura, Ways of Thinking of Eastern Peoples, p. 190.
Another major criticism, and a primary difﬁcu!ty in the application of the Five Phases theory to medicine, is its lack of consistency. To fit the theory to reality, the referents of the Phases and the relationships between them haye continually been changed and corrupted. The results of such corruption cap be seen in Tables 74 and 75 on the clinical use of the Five Phases.
Such a problem exists in all traditional systems of elemental correspondence. The original classical Greek formulation by Empedocles of Agrigentum (c. 504-433 B.C.E.) is a system in which the basic elements of fire, earth, water, and air were considered the ultimate constituents of matter and were associated with various other categories of four such as the four fundamental qualities and the four humors. All varieties and changes in the world were associated with different mixtures of the four elements. [….]
Kaptchuk (1983), p. 352
 To get a sense of the cultural, physiological, scientific, ideological, religious, and intellectual factors that are involved in a correspondence system, it is worth examining the transition from the Aristotelian system of Four Elements to the Paracelsian Three Elements (tria prima: salt, sulphur and mercury) in sixteenth-century Europe. an interesting discussion appears in Allen G. Dobus, “The Medico-Chemical World of the Paracelsians,”, in Changing Perspectives in the History of Science, ed. by Mikaluas Teich and Robert Young (Dordrecht, Holland, and Boston: D. Reidel Pub. Co., 1973), pp. 88-92
Western practitioners of acupuncture and Chinese medicine have special problems dealing with the Five Phases theory. The major difficulty is that much of the literature available in English describes diagnosis and treatment exclusively in terms of Five Phases theory. Writings that refer to the theory as the “Law of the Five Elements” betray a misunderstanding of Chinese science—natural laws such as those promulgated by Aristotle and Newton simply were not developed in traditional China. These writings also put undue emphasis on the importance of the Five Phases to the Chinese medical tradition; even respected defenders of the Five Phases theory readily admit sometimnes it is useful and sometimes it is not. Even so, it is unfortunate many practitioners simply consider Five Phases theory unscientific gibberish, and do not try to understand it. It is actually an important secondary emblem system used to assess and discuss clinical reality.
 An example is Denis and Joyce Lawson-wood, The Five Elements of Chinese Acupuncture and Massage (Rustington, England: Health Science Press, 1965). The English overemphasis on the Five Phases is not derived from the Chinese tradition. Instead, the fascination of European acupuncturists with this method is due to the influence of the “Nan Jing traditional acupuncture movement” and to to somem of the Kei Raku Khi-Riyo (Meridian Treatment) schools, both of which developed around the turn of the twentieth century, in Japan. The European adoption of this method stems partly from a desire for an exotic schema and partly from lack of adequate information.
 See Needham’s discussion of Chinese thought and “law” in Grand Titration, pp. 299-330.
 Qin Bo-wei, Medical Lecture Notes, p. 22.
 An example is Frank Z. Warren, Handbook of Medical Acupuncture (New York: Van Nostrand Reinhold Co., 1976).
Kaptchuk, Ted J. 1983. The Web That Has No Weaver: Understanding Chinese Medicine. Chicago: Congdon & Weed.
The field theory in psychology by #KurtLewin 1943 derives from classical field theory (viz. electromagnetism and gravitation), predating quantum field theory (viz. subatomic particles). For psychology, Lewin wrote in 1943 how history (and a subjective view of the future) matters.
It is correct that field theory emphasizes the importance of the fact that any event is a resultant of a multitude of factors. The recognition of the necessity of a fair representation of this multitude of interdependent factors is a step in the direction toward field theory. However, this does not suffice. Field theory is something more specific. To use an illustration: Success in a certain sport may de- pend upon a combination of muscular strength, velocity of movement, ability to make quick decisions, and precise perception of direction and distance. A change in any one of these five variables might alter the result to a certain degree. One can represent these variables as five dimensions of a diagram. The resultant of any possible constellation of these factors for the amount of success can be marked as a point in the diagram. The totality of these points then is a diagrammatic representation of this dependence, in other words, of an empirical law. Physics frequently makes use of such representation of a multitude of factors influencing an event. To each of certain properties, such as temperature, pressure, time, spacial position, one dimension is coordinated. Such a representation in physics is called ‘phase space.’ Such a phase space may have twenty dimensions if twenty factors have to be considered. A phase space is something definitely different from that three-dimensional ‘physical space’ within which physical ob- jects are moving. In the same way the psychological space, the life space or psychological field, in which psychological locomotion or structural changes take place, is something different from those diagrams where dimensions mean merely gradations of properties.
Lewin (1943), p. 293
Lewin probes the question of what is a field theory, and what might not be a field theory.
Field theory, therefore, can hardly be called correct or incorrect in the same way as a theory in the usual sense of the term. Field theory is probably best characterized as a method: namely, a method of analyzing causal relations and of building scientific constructs. This method of analyzing causal relations can be expressed in the form of certain general statements about the’ nature’ of the conditions of change. To what degree such a statement has an ‘analytical’ (logical, a priori) and to what degree it has an ’empirical’ character do not need to be discussed here.
Lewin (1943), p. 294
By section 2, “The Principle of Contemporaneity and the Effect of Past and Future”, Lewin aims for rigour by using mathematical notation (which isn’t beyond high school Grade 12 level).
The equivalent to (dx/dy) in physics is the concept ‘behavior’ in psychology, if we understand the term behavior to cover any change in the psychological field. The field theoretical principle of contemporaneity in psychology then means that the behavior b at the time t is a function of the situation S at the time t only (S is meant to include both the person and his psychological environment) … and not, in addition, a function of past or future situations … (Fig. 2).
Lewin (1943), p. 297
In section 3, “How to Determine the Properties of a Field at a Given Time”, Lewin compares the science of psychology with medicine (and engineering, physics and biology).
If one has to derive behavior from the situation at that time, a way has to be found to determine the character of the ‘situation at a given time.’ This determination implies a number of questions which are, I think, interesting both psychologically and philosophically. To determine the properties of a present situation or — to use a medical terminology — to make a diagnosis, one can follow two different procedures: One may base one’s statement on conclusions from history (anamneses}, or one may use diagnostic tests of the present,
Lewin (1943), p. 297
Medicine, engineering, physics, biology are accustomed to use both methods, an inquiry into the past and a test of the present. But they prefer the latter whenever possible. 
Lewin (1943), p. 298
 There are cases where a historical procedure is preferable. For instance, the hunger of a rat can probably be better determined by the duration of starvation than by a physiological or psychological test of the hunger at the time t. This conclusion from the past to the present can be made, however, only during periods and in settings where a ‘closed system’ (no interference from outside) can be enforced; e.g., for animals which during this period do the same amount of work, which have been on a known diet, etc. The difficulties of this type of control have lead Skinner (19) to link the problem of drive strength to properties of present consumption.
Psychology has used diagnosis by anamneses rather excessively, particularly in classical psychoanalysis and other clinical approaches to problems of personality. Psychology of perception and psychology of memory have been relatively free from the historical type of diagnosis. Experimental psychology, on the whole, has shown a progressive trend toward testing the present situation.
Lewin (1943), p. 298
In section 4, “The Psychological Past, Present, and Future as Parts of Psychological Field at a Given Time” departs from physics.
The clarification of the problem of past and future has been much delayed by the fact that the psychological field which exists at a given time contains also the views of that individual about his future and past. The individual sees not only his present situation; he has certain expectations, wishes, fears, daydreams for his future. His views about his own past and that of the rest of the physical and social world are often incorrect, but nevertheless constitute, in his life space, the ‘reality-level’ of the past. In addition, a wish- level in regard to the past can frequently be observed. The discrepancy between the structure of this wish- or irreality- level of the psychological past and the reality-level plays an important role for the phenomenon of guilt. The structure of the psychological future is closely related, for instance, to hope and planning (2).
Lewin (1943), p. 302-303
Following a terminology of L. K. Frank (6), we speak of ‘time perspective’ which includes the psychological past and psychological future on the reality-level and on the various irreality-levels. The time perspective existing at a given time has been shown to be very important for many problems such as the level of aspiration, the mood, the constructiveness, and the initiative of the individual. Farber (4) has shown, for instance, that the amount of suffering of a prisoner depends more on his expectation in regard to his release, which may be five years ahead, than on the pleasantness or unpleasantness of his present occupation. It is important to realize that the psychological past and the psychological future are simultaneous parts of the psychological field existing at a given time t. The time perspective is continually changing. According to field theory, any type of behavior depends upon the total field, including the time perspective at that time, but not, in addition, upon any past or future field and its time perspectives.
Lewin (1943), p. 303
The the last section, 5, on “Psychological Ecology”, Lewin responds to some issues brought up by Brunswik.
Within the realm of facts existing at a given time one can distinguish three areas in which changes are or might be of interest to psychology: 1. The ‘life space’; i.e., the person and the psychological environment as it exists for him. We usually have this field in mind if we refer to needs, motivation, mood, goals, anxiety, ideals. 2. A multitude of processes in the physical or social world, which do not affect the life space of the individual at that time. 3. A ‘boundary zone’ of the life space: certain parts of the physical or social world do affect the state of the life space at that time. The process of perception, for instance, is intimately linked with this boundary zone because what is perceived is partly determined by the physical ‘stimuli’; i.e., that part of the physical world which affects the sensory organs at that time. Another process located in the boundary zone is the ‘execution’ of an action. [….]
Lewin (1943), p. 306
The essence of explaining or predicting any change in a certain area is the linkage of that change with the conditions of the field at that time. This basic principle makes the sub- jective probability of an event a part of the life space of that individual. But it excludes the objective probability of alien factors that cannot be derived from the life space.
Many who cite #KurtLewin haven’t read the original 1947/1951 writings, say @strategybuild@ToddBridgman@kgbphd with the “refreezing” part of “unfreezing → changing → refreezing” emerging in a subsequent career of an idea that can be traced genealogically and archaeologically.
Kurt Lewin is widely considered the founding father of change management, with his unfreeze–change–refreeze or ‘changing as three steps’ (CATS) (see Figure 1 …) regarded as the ‘fundamental’ or ‘classic’ approach to, or classic ‘paradigm’ for, managing change ….
Cummings, Bridgman, Brown (2016), p. 34
CATS has come to be regarded both as an objective self-evident truth and an idea with a noble provenance.
Cummings, Bridgman, Brown (2016), p. 34
The authors suggest going back to reread the original Lewin 1947 paper, to remove some of the distortions introduced with multiple reinterpretations.
By going back and looking at what Lewin wrote (particularly the most commonly cited reference for CATS, ‘Lewin, 1947’: the first article ever published in Human Relations published just weeks after Lewin’s death), we see that what we know of CATS today is largely a post hoc reconstruction. Our forensic examination of the past is not, however, an end in itself. Rather, it encourages us to think differently about the future of change management that we can collectively create. In that spirit, we conclude by offering two alternative future directions for teaching and researching change in organization inspired by returning to ‘Lewin, 1947’ and reading it anew.
Cummings, Bridgman, Brown (2016), p. 35
Lewin (1947) does have a subheading as “Changing as Three Steps: Unfreezing, Moving, and Freezing of Group Standards”, but doesn’t use the term “refreezing”.
Lewin never wrote ‘refreezing’ anywhere. As far as we can ascertain, the re-phrasing of Lewin’s freezing to ‘refreezing’ happened first in a 1950 conference paper by Lewin’s former student Leon Festinger (Festinger and Coyle, 1950; reprinted in Festinger, 1980: 14). Festinger said that: ‘To Lewin, life was not static; it was changing, dynamic, fluid. Lewin’s unfreezing-stabilizing-refreezing concept of change continues to be highly relevant today’. It is worth noting that Festinger’s first sentence seems to contradict the second, or at least to contradict later interpretations of Lewin as the developer of a model that deals in static, or at least clearly delineated, steps. Furthermore, Festinger misrepresents other elements; Lewin’s ‘moving’ is transposed into ‘stabilizing’, which shows how open to interpretation Lewin’s nascent thinking was in this ‘preparadigmatic’ period (Becher and Trowler, 2001: 33).
Cummings, Bridgman, Brown (2016), p. 37
The “Change as Three Steps” idea can be traced backwards (genealogically) before 1980, and then moving forward (archaeologically) after 1980.
Prior to the early 1980s, Lewin’s CATS was largely unseen; by the end of the 1980s, despite the fact that its form was anomalous to what Lewin actually wrote or likely intended for the idea, it was the basis of our understanding of a fast growing field: change management.
Cummings, Bridgman, Brown (2016), p. 41
Kurt Lewin passed away at age 56 in 1947, with a heart attack. The 1947 paper is titled “Frontiers in Group Dynamics”. Where might he have continued research, if the untimely interruption had not occurred?
Lewin outlines many frontiers in the 1947 paper from which CATS is developed, but the two to which he devotes the most space, and which interconnect to most of the other frontiers he wrote about, are the first and the last in the article. The first is that when studying change the unit of analysis must be the group, not the individual (as psychology might direct us), the organization (as modern management studies is want to think) or wider society (as may be the want of the sociologist). The last is a call for advances in mathematics and statistics, advances that would enable multiple variables relating to individuals and groups to be analysed as a system, so as to enable the other frontiers he has outlined to be reached. Seeing these two aims as foundations for the future could, we believe, have profound effects on research and teaching now.
Human organizations may learn from wolves, with groups of 2 to 6 taking down elk, and cooperative expert groups of 9 to 13+ taking down larger bison. #DanielMacNulty, #AimeeTallian #DanielRStahler #DouglasWSmith (2014).
Abstract: [….] Whereas improvement in elk capture success levelled off at 2–6 wolves, bison capture success levelled off at 9–13 wolves with evidence that it continued to increase beyond 13 wolves. These results are consistent with the hypothesis that hunters in large groups are more cooperative when hunting more formidable prey. Improved ability to capture formidable prey could therefore promote the formation and maintenance of large predator groups, particularly among predators that specialize on such prey.
Group-size specific success of wolves hunting bison
The influence of group size on the success of wolves attacking and capturing bison was not linear (Fig. 2). The top models of attacking and capturing included a linear spline for group size (Table S1), indicating a threshold at which the effect of group size on hunting success suddenly changed. [….]
The threshold group size was smaller for attacking than for capturing. The confidence set of spline models for each predatory task (Table S1) indicates the threshold group size was 3–6 wolves for attacking and 9–13 wolves for capturing. The most parsimonious models in the set included thresholds at 4 and 11 wolves for attacking and capturing, respectively (Fig. 2a–b). […]
Comparative effects of group size on the success of wolves hunting bison and elk
… attack and capture success were effectively constant beyond each threshold. Below these thresholds, each additional wolf had a slightly larger effect on the odds of attacking bison (OR = 1.67) versus elk (OR = 1.45; Fig. 3a) but a similar effect on the odds of capturing each species (bison: OR = 1.40; elk: OR = 1.44; Fig. 3b).
Whereas the threshold group size of wolves attacking bison and elk was the same (4 wolves; Fig. 3a), the threshold group size of wolves capturing bison (11 wolves) was nearly 3 times larger than that of wolves capturing elk (4 wolves; Fig. 3b).
Completing tasks in teams of two produces the most satisfaction, but members are most comfortable with 4 or 5 people, found Hackman & Vidmar (1970).
Experimental laboratory. The experiment was run simultaneously at two institutions (Yale University and the University of Illinois, Urbana) using male undergraduates at each institution as subjects.
Hackman and Vidmar (1970), p. 40
What is the optimal team size? Research by Slater (1958) suggests one straightforward means of estimating the “optimal” group size — simply determine what size group members prefer. Although both Hare (1952) and Slater find a general increase in dissatisfaction as size increases (a finding replicated by this study), Slater further proposes that five-person groups may be optimal. The reason, Slater suggests, is that smaller groups are too intimate and members may be inhibited from expressing disagreements in them.
Hackman and Vidmar (1970), pp. 47-48
 It should be noted, however, that studies by Ziller (1957) and Miller (reported by Thomas & Fink, 1963) found no consistent relationship between size and member satisfaction.
The present data allow reexamination of Slater’s conclusion. Items one and two of the Member Reaction Questionnaire (“the group is too small”; “the group is too large”) reflect two opposing types of general dissatisfaction with the group size. If item scores are standardized (assuming interval data) and the data is plotted on a graph with size on the abcissa and satisfaction on the ordinate, the intersection of the two items will indicate the point of optimal reported satisfaction with the size of the group. Since neither task type nor laboratory interacted with size, the data were averaged across these variables before converting to standard scores. The results are shown in Figure 1. Consistent with Slater’s finding, optimal satisfaction with size is found between four and five members. Slater’s groups were from a single population and worked only on “human relations” tasks; the conclusion may now be generalized over three types of intellective tasks and two laboratory populations.
Hackman and Vidmar (1970), pp. 48-49
Yet the finding that members are most comfortable with groups of size four or five is, in some ways, inconsistent with other data from the same people. According to items on the Member Reaction Questionnaire, members of dyads were clearly the most satisfied, and dissatisfaction increased, in approximately linear fashion, from size three to size seven. Further, the middle-sized groups (i.e., sizes three through five) were less creative than the dyads or the relatively large groups. Why, then, should members of these groups report that they are the most satisfied with the size of their groups? It may be that members of smaller groups feel unusually “exposed” and, while in fact they experience few objective difficulties in working together, they are still vaguely uncomfortable. The present data do not, unfortunately, address this possibility. The data are clear for larger groups. In these groups, members are unhappy, and the reasons center around the coordination difficulties they encounter (see Table 2). Yet even if the above line of reasoning is valid, we must explain why performance tended to be less adequate in middle-sized groups than in dyads and in very large groups.
Hackman and Vidmar (1970), pp. 49
[Editorial note: In Table 2, Group Product Characteristics are: (i) Action orientation; (ii) Length; (iii) Originality; (iv) Optimism; (v) Quality of presentation; (vi) Issue involvement; and (vii) Creativity.]
One possibility is that middle-sized groups are, in a sense, too comfortable for their own good. It appears that members of dyads may have responded to their “exposure” by pouring their energies into task performance. And, since there are very few coordination problems in these groups, the result was relatively good performance.
Hackman and Vidmar (1970), pp. 49
Source: Hackman, J. Richard, and Neil Vidmar. “Effects of size and task type on group performance and member reactions.” Sociometry (1970): 37-54. https://www.jstor.org/stable/2786271
Slater, Philip E. “Contrasting correlates of group size.” Sociometry 21, no. 2 (1958): 129-139.
Follow the Rule of Seven for meetings. Who should come to a meeting is always a sensitive issue, and the basic precept is often “The more the merrier.” But more is rarely better when it comes to making decisions. Our research highlights what we might call the Rule of Seven: every person added to a decision-making group over seven reduces decision effectiveness by 10 percent. If you take this rule to its logical conclusion, a group of seventeen or more rarely makes any decisions. Of course, a larger group may sometimes be necessary to ensure buy-in. But organizations trying to make important decisions should limit the size of group as much as possible.