Welcome to the fourth post about the ‘General Theory of Behaviour’. The theory holds that psychological homeostasis is a fundamental process in behaviour and motivation. Psychology is here considered a natural science. The General Theory is an attempt to unify Psychology as a discipline that has been chronically disintegrated over its history. The General Theory is a work in progress and will not be finished in this author’s lifetime.
I begin with Claude Bernard, the French Physiologist, who said:
The fixity of the milieu supposes a perfection of the organism such that the external variations are at each instant compensated for and equilibrated…. All of the vital mechanisms, however varied they may be, have always one goal, to maintain the uniformity of the conditions of life in the internal environment…. The stability of the internal environment is the condition for the free and independent life.
Claude Bernard (1813-1878)
I visited Claude Bernard’s original cottage at Saint Julien in the Beaujolais wine region, north of Lyon. I viewed Bernard’s writing desk, chair, fireplace and sampled the wine from the vineyard. Bernard was one of the world’s rare geniuses.
What is psychological homeostasis?
Sixty-one years after Claude Bernard (1865) wrote about the ‘internal milieu’, Walter B. Cannon (1926) coined the term ‘homeostasis’.[1] Then, 16 years later, psychobiologist Curt Richter (1942) expanded the homeostasis idea to include behavioural or ‘ total organism regulators’ in the context of feeding.[2] From this viewpoint, ‘external’ behaviours that are responses to environmental stimuli lie on a continuum with ‘internal’ physiological events. For Richter, behaviour includes all aspects of feeding necessary to maintain the internal environment.
Bernard and Cannon focused on the physiological form of homeostasis, ‘H[Φ]’. I wish to convince the reader that the ‘external milieu’, our interactions with the proximal world of socio-physical action, involves another equally important type of homeostasis. Psychological Homeostasis (aka Behavioural Homeostasis) is as important to survival and a healthy life as the air we breathe and the water we drink. Psychological Homeostasis is the ‘Governor’, willing every being to its bidding, while all the while one is absorbed by the illusion of illusions, that one has absolute freedom of choice independent of all natural causes.
The General Theory of Behaviour (GTB) extends homeostasis to all forms of behaviour. Psychological homeostasis can be explained in two stages, starting with the classic version of homeostasis in Physiology, H[Φ], followed by the operating features of its psychological sister, H[Ψ].
How does the system work?
The essential features are illustrated in Figure 2.1.
Figure 2.1 Upper panel: A representation of Physiological (Type I) Homeostasis (H[Φ]). Adapted from Modell et al. (2015). Lower panel: A representation of Psychological (Type II) Homeostasis (H[Ψ]).
To be counted as homeostasis, H[Φ], a system is required to have five features:
- It must contain a sensor that measures the value of the regulated variable.
- It must contain a mechanism for establishing the “normal range” of values for the regulated variable. In the model shown in Figure 2.1, this mechanism is represented by the “Set point Y”.[3]
- It must contain an “error detector” that compares the signal being transmitted by the sensor (representing the actual value of the regulated variable) with the set range. The result of this comparison is an error signal that is interpreted by the controller.
- The controller (or Governor) interprets the error signal and determines the value of the outputs of the effectors.
- The effectors are those elements that determine the value of the regulated variable. The effectors may not be the same for upward and downward changes in the regulated variable.
Identical principles apply to Physiological (Type I) and Psychological (Type II) Homeostasis (H[Ψ] yet two notable differences exist in the structure of the mechanism (Figure 2.1, lower panel).
Type I, Physiological Homeostasis, is ‘inward facing’ and Type II, Psychological Homeostasis, is both ‘outward’ and ‘inward facing’. The latter possesses two sets of effectors, inward and outward. The conceptual boundary between the internal and external environments lies between the controller and the outward effectors of the somatic nervous system, i.e. the muscles that control speech and action.
Psychological Homeostasis operates with intention, purpose, and desire. It is the mechanism of Agency.
Striving and thriving
The individual organism extends its ability to thrive in nature with Type II homeostasis. A prime example is ‘niche construction’. Self-extension by niche construction creates zones of safety, one of the primary goals of Type II homeostasis. Niche construction amplifies the organism’s ability to occupy and control the environment proximally and distally.
The use of tools for hunting, weapons for aggression, fire for cooking, domestication of animals, the use of language, money, goods for trade and commodification, agriculture, science, technology, engineering, medicine, culture, music literature and social media are all methods of expanding and projecting niches of safety, well-being and control. It is often said that this is the ‘Age of Materialism’. It is also said that ‘Money does not bring happiness’. These two sayings provide the essence of AP007:
Individual ownership of assets such as land, buildings, companies, stocks and shares reflect a universal need to extend occupation, power and control but these possessions do not necessarily increase the subjective well-being of the owner [AP 007].
Super-rich people such as Bill and Melinda Gates give charitable donations to help the less well off and organisations such as the World Health Organisation. Philanthropy is not simply about tax breaks, it satisfies the fundamental human motive to do well by others. It is an act of giving governed by the drive for harmony and balance that is Psychological Homeostasis.
Acts of kindness or altruism can be observed on a daily basis with people anywhere. There is basic link between the sociality in acts towards others and positive feelings about oneself. It feels good to give and to help. To be kind. It’s kindness – not money – that makes the world go round.
A recent paper by Paul J Eslinger et al. (2021) concerns ‘The neuroscience of social feelings”The paper begins: “A “feeling” is a fundamental construct in the behavioral, neurobiological and social psychological sciences encompassing a range of subjective experiences. Many of these experiences relate to homeostatic aspects of survival and life regulation (Buck, 1985; Damasio and Carvalho, 2013; LeDoux, 2012; Panksepp, 2010; Strigo and Craig, 2016).” I could hardly agree more!
Initiated by the brain and other organs, homeostasis of either type often acts in anticipatory or predictive mode. The prediction of rewards and dangers is the principal function of any living organism.
A simple example is the anticipation of a meal with a few tummy rumbles. The pre-prandial secretion of insulin, ghrelin and other hormones enables the consumption of a larger nutrient load with minimal postprandial homeostatic consequences. Eat more, but suffer less.
When a meal containing carbohydrates is to be consumed, a variety of hormones is secreted by the gut that elicit the secretion of insulin from the pancreas before the blood sugar level has actually started to rise.[4]
Similar principles operate in Type II homeostasis acting with the brain as a “prediction machine”. When we anticipate a pleasant event such as a birthday party, there is a preparatory ‘glow’ which can change one’s mood in a positive direction, or thinking about an impending visit to the dentist may produce anxiety, or the receipt of a prescription from one’s physician may give improvements in symptoms, even before any medicines are taken, a pure placebo effect.
Similar predictive phenomena occur at societal level in providing security which has a protective function:
At societal level, anticipation enables rational mitigation, e.g. anticipation of demographic changes influences policy, threat from hostile countries influences expenditure on defence, and the threat of a new epidemic influences programmes of prevention. [AP 008].
All of the above have been witnessed in recent history.
Homeostasis involves several interacting processes in a causal network. A homeostatic adjustment in one process necessitates a compensatory adjustment in one or more of the other interacting processes.
To illustrate this situation, consider an example from immunology: what happens in phosphate homeostasis (Figure 2.2). Many REF-behaviours are isomorphic with the 4-process structure in Figure 2.2.[5] However, in nature there is no restriction on the number of interconnected processes and also any process can belong to multiple homeostatic networks. Thus there is an enormous number interconnected networks in constant flux with the setting and resetting of a multitude of targets and goals.
Figure 2.2 Phosphate homeostasis. A decrease in the serum phosphorus level causes a decrease in FGF23 and parathyroid hormone (PTH) levels. Increase in serum phosphorus leads to opposite changes. Calcitriol increases serum phosphorus and FGF23, while it decreases PTH. Increase in FGF23 leads to decrease in PTH and calcitriol levels. PTH increases calcitriol and FGF23 levels. Reproduced from Jagtap et al. (2012)[6] with permission.
Homeostasis never rests
It is continuous, comprehensive and thorough. With each round of the REF, all of the major processes in a network are reset to maintain stability of the whole system. The REF process goes through a continuous series of ‘reset’ cycles each of which stabilizes the system until the next occasion one of the processes falls outside its set range and another reset is required.[7]
Processes in Type II homeostasis may vary along quantitative axes or they can have discrete categorical values. For example, values, beliefs, preferences and goals can have discrete values, as does the state of sleep or waking. Any change in the organism’s response towards an external stimulus e.g. answering ‘yes’ or ‘no’ or ‘don’t know’ to a question, has knock-on effects:
Any change in a categorical process involves change throughout the network to which it belongs. [AP 009].
Such changes may be rapid, in the millisecond range, e.g. a changed preference from chocolate chip cookie flavoured ice cream to Madagascar vanilla that may occurs an instant after arriving at the ice-cream kiosk.
At the other end of the spectrum of importance, in buying a new apartment, the final choice might also occur in the instant the preferred option is first sighted. Or a decision could take months or years even though it is of precious little consequence, e.g. deciding that one is a republican rather than a monarchist, or it may never occur because we simply do not care one way or the other. These considerations lead to a surprising proposition that:
The speed of a decision is independent of its subjective utility [AP 010].
One objective of A General Theory of Behaviour is to explain the relevance of the REF system to Psychology. We know already that the regulation of action is guided by three fundamental systems: (i) the brain and central nervous system (CNS), (ii) the endocrine system (ES) and (iii) the immune system (IS).
These three systems collectively govern both physiology and behaviour using the two types of homeostasis, H[Φ] and H[Ψ], respectively. We can understand how this collective executive control might be possible using a recently discovered ‘central homeostatic network’.
The ‘Central Homeostatic Network’
How are the two homeostasis systems integrated and coordinated to work towards common goals? Imagine the chaos that would ensue if system 1 said ‘stop’ and system 2 said ‘go’. Both systems must work in concert with a single conductor, one system of central control. Recent studies reveal the existence of the necessary kind of central control – what could be given the name of the ‘Governor’.
Recent analyses of the CNS have explored new methods for discovering cortical and subcortical networks in the brain’s anatomical connectivity termed the ‘connectome’. These studies of the connectome are revolutionary in showing that the CNS is at once both more complex and more simple that previously assumed. Let me explain why.
Regions of interest (ROI) are observed as coherent fluctuations in neural activity at rest as well as distributed patterns of activation or ‘networks’. A network is any set of pairwise relationships between the elements of a system—formally represented in graph theory as ‘edges’ linking ‘nodes’.
Neurobiological networks occur at different organizational levels from cell-specific regulatory pathways inside neurones to interactions between systems of cortical areas and subcortical nuclei. Architectures which support cognition, affect and action are normally found at the highest level of analysis.[8]
Deep within the human forebrain lies a group of structures that play major roles in autonomic, respiratory, neuroendocrine, emotional, immune, and cognitive adaptations to stress. Collectively, these forebrain structures have been known, in part, as the limbic system, a term that retains usefulness today due to their anatomic proximity to the hypothalamus, robust mono- and/or oligo-synaptic connectivity to one another, and shared participation in homeostasis.
Edlow et al., 2016.
In thlandmark study, Brian Edlow and his colleagues investigated the limbic and forebrain structures that form the ‘Central Homeostatic Network’.[9] The Central Homeostatic Network (CHN) appears to control autonomic, respiratory, neuroendocrine, emotional, immune, and cognitive adaptations to stress. Collectively, these forebrain structures include the limbic system close to the hypothalamus with strong mono- and/or oligo-synaptic connectivity to one another, and shared participation in homeostasis. Homeostatic forebrain nodes receive sensory information concerning extrinsic threats and interoceptive information from the brainstem, resulting in arousal, attention and vigilance during waking, and visceral and somatic motor defences.
There is complexity here but a well-organized complexity. CHN connectogram shows all six brainstem seed nuclei are interconnected with all seven limbic forebrain target sites, but with markedly different streamline probabilities (SPs) (Figure 2.3). The SP measures the probability of a streamline connecting a seed ROI and target ROI, but does not reflect the strength of the neuroanatomic connection. To ensure that the target ROI size was not the only factor contributing to the SP, Edlow and colleagues verified that the SP measurements were derived from anatomically plausible pathways from animal or other studies of subcortical pathways in the human brain.
Figure 2.3. The connectogram of the human Central Homeostatic Network (CHN). Brainstem seed nodes are displayed on the outside of the connectogram and limbic forebrain target nodes at its center. Connectivity is represented quantitatively, with line thickness being proportional to the streamline probabilities for each dyad. Brainstem seed nodes consist of 7 structures as follows: the hippocampus (Hypo); amygdala (Amg); subiculum (Sub); entorhinal cortex (Ent); superior temporal gyrus (anterior) (STGa); superior temporal gyrus (posterior) (STGp); and insula (Ins). Connectogram lines go to the brainstem nucleus of origin: dorsal raphe DR; median raphe MR; locus coeruleus, LC; paragigantocellularis lateralis, PGCL; caudal raphe, CR; vagal complex, VC. Reproduced in slightly adapted form by permission from Edlow, McNab, Witzel & Kinney (2016).
Brian Edlow’s group study findings suggest that H[Φ] is mediated by ascending and descending interconnections between brainstem nuclei and forebrain regions, which together regulate autonomic, respiratory, and arousal responses to stress.
The limbic system has been regarded as the neuroanatomic substrate of ‘emotion’, but its role in the regulation of homeostasis is also now being recognized, and the limbic system has been added to the central autonomic network of “flight, fight or freeze”.
Edlow et al. concluded as follows: “connectivity between forebrain and caudal brainstem regions that participate in the regulation of homeostasis in the human brain. These nodes and connections form, we propose, a CHN because its nodes not only regulate autonomic functions such as ‘‘fight or flight’’ and arousal (e.g., median and dorsal raphe, and locus coeruleus) but also non-autonomic homeostatic functions such as respiration (i.e., PGCL) and regulation of emotion/affect (e.g. amygdala)” (Edlow et al., op cit., p. 196).
This study supports the idea that interconnected brainstem and forebrain nodes form an integrated Central Homeostatic Network in the human brain.
To put this in the simplest terms, the forebrain is involved in homeostatic regulation of both autonomic (Type I) and non-autonomic (Type II) human responses to disturbances of equilibrium. The forebrain provides a common central mechanism for both types of homeostasis, H[Φ] and H[Ψ].
Principle III (Communality): Homeostasis of Types I and II are controlled by a single executive controller in the forebrain.
That the forebrain evolved to control both types of homeostasis, inside the body and in outwardly directed behaviour, supports our contention that homeostasis is a unifying concept across Biology and Psychology. Everything we know about the executive role of the forebrain in action planning and decision-making suggests that this must indeed be the case. Why have two control systems when only one is necessary? The simplicity is beautiful.
A unifying principle
In the Epilogue to ‘The Wisdom of the Body’, Walter Cannon inquired whether there are any general principles of homeostasis acting across industrial, domestic and social forms of organization? He suggested that the homeostasis of individual humans is dependent on ‘social homoeostasis’ via cooperation within communities. He talks analogously of the system of distribution of goods in society as a stream: “Thus the products of farm and factory, of mine and forest, are borne to and fro. But it is permissible to take goods out of the stream only if goods of equivalent value are put back in…Money and credit, therefore, become integral parts of the fluid matrix of society” (p. 314). He believed that “steady states in society as a whole and steady states in its members are closely linked.” (p. 324).[10]
Compared to more economically stable societies, societies in steep economic growth or decline are expected to have a relatively high prevalence of mental illness [AP 011].
Compared to more egalitarian societies, societies with high levels of inequality are expected to have a relatively high prevalence of mental illness [AP 012].
Ludwig von Bertalanffy (1968)[11] was critical of these externally directed, social forms of homeostasis (Type II). He did not support the idea that homeostasis could be applied to spontaneous activities, processes whose goal is not reduction but building up of tensions, growth, development, creation, and in human activities which are non-utilitarian. There are good reasons to think that von Bertalanffy was wrong. The reach of homeostasis extends well beyond Physiology into many realms of Psychology and even into Society as a whole. H[Φ] and H[Ψ] serve identical stabilizing functions internally in the body and externally in socio-physical interactions of behaviour respectively. With Cannon, we accept that “steady states in society as a whole and steady states in its members are closely linked.” H[Φ] and H[Ψ] exist in a complementary relationship of mutual support. It could not be otherwise.
Principle IV (Steady Stable State): Homeostasis Type II serves the same function for Behaviour as Homeostasis Type I serves for Physiology: the production of a stable and steady state.
According to this principle, behaviour produced by most people most of the time is intended to generally calm ‘waves of unrest’ rather than to make the waves larger, to reduce conflict and to produce cooperation, safety and stability. People with high levels of self-control tend to create social stability and have more, and longer-lasting, friendships than people with relatively low levels of self-control. [AP 013].
Individual set ranges for any particular process vary across people and are not the same for all individuals. Individual set ranges are based on unique interactions of genetics, epigenetics and early infant experience. Set ranges may be changed in a few specific disorders and individual differences exist in the rate and extent of the reset following perturbations to equilibrium. The General Theory carries the expectation of wide individual differences across time and space in set ranges, rates of reset, and adaptations over time.
Conclusions
1) All behaviour involves Type II homeostasis, which strives for a stable and steady state in the socio-physical world.
2) A single executive controller or ‘Governor’ in the forebrain regulates both type of homeostasis.
3) Individual set ranges are based on genetics, epigenetics and early infant experience. They are normally fixed, changing only with major disorders of function.
REFERENCES:
[1] Cannon, W.B. (1926). Physiological regulation of normal states: some tentative postulates concerning biological homeostatics. In A. Pettit. A Charles Richet : ses amis, ses collègues, ses élèves. Paris: Les Éditions Médicales. p. 91.
[2] Richter, C. P. (1942). Increased dextrose appetite of normal rats treated with insulin. American Journal of Physiology-Legacy Content, 135(3), 781-787.
[3] It is accepted that so-called ‘set points’ are really ‘set ranges’, e.g. the “normal” human body temperature is a range from 97°F (36.1°C) to 99°F (37.2°C). We use the terms ‘set point’ and ‘set range’ interchangeably.
[4] Moore-Ede, M. C., & Herd, J. A. (1977). Renal electrolyte circadian rhythms: independence from feeding and activity patterns. American Journal of Physiology-Renal Physiology, 232(2), F128-F135.
[5] Unless stated otherwise, an arrow in any diagram in this book represents a causal effect.
[6] Jagtap, V. S., Sarathi, V., Lila, A. R., Bandgar, T., Menon, P., & Shah, N. S. (2012). Hypophosphatemic rickets. Indian journal of endocrinology and metabolism, 16(2), 177.
[7] The term ‘homeorhesis’, meaning a stabilized flow, has also been proposed because reference sets are liable to change. The terms “allostasis” and “heterostasis,” are overlapping with “homeostasis” but are not generally adopted. See: Day, TA (2005). Defining Stress as a Prelude to Mapping Its Neurocircuitry: No Help from Allostasis, Progress in Neuro-psychopharmacology and Biological Psychiatry, 29, 1195–1200.
[8] Petersen, S.E. & Sporns, O. (2015) Brain networks and cognitive architectures. Neuron 88, 207 – 219.
[9] Edlow, B. L., McNab, J. A., Witzel, T., & Kinney, H. C. (2016). The structural connectome of the human central homeostatic network. Brain connectivity, 6(3), 187-200.
[10] Evidently this is the opinion of one of Bill Gates who holds that foreign aid helps to stabilize the developing world and thereby the security and stability of the USA. See: http://time.com/4704550/bill-gates-cutting-foreign-aid-makes-america-less-safe/
[11] Von Bertalanffy, L. (1968). General system theory. New York. See p. 210.