How Gut Feeling Sometimes Gets It Right

BACKGROUNDMany of the reproductive decisions that humans make happen without much planning or forethought, arising instead through the use of simple choice rules or heuristics that involve relatively little information and processing. Nonetheless, these heuristic-guided decisions are typically beneficial, owing to humans' ecological rationality - the evolved fit between our constrained decision mechanisms and the adaptive problems we face.OBJECTIVEThis paper reviews research on the ecological rationality of human decision making in the domain of reproduction, showing how fertility-related decisions are commonly made using various simple heuristics matched to the structure of the environment in which they are applied, rather than being made with information-hungry mechanisms based on optimization or rational economic choice.METHODSFirst, heuristics for sequential mate search are covered; these heuristics determine when to stop the process of mate search by deciding that a good-enough mate who is also mutually interested has been found, using a process of aspiration-level setting and assessing. These models are tested via computer simulation and comparison to demographic age-at-first-marriage data. Next, a heuristic process of feature-based mate comparison and choice is discussed, in which mate choices are determined by a simple process of feature-matching with relaxing standards over time. Parental investment heuristics used to divide resources among offspring are summarized. Finally, methods for testing the use of such mate choice heuristics in a specific population over time are then described.1. IntroductionHumans make a variety of reproductive decisions throughout their lives, with the most important including who to choose as a mate, when to have offspring with that mate, and how to raise the children that result. Some of these decisions are consciously planned with great deliberation; others (probably the majority) may come about without deep thought, guided instead by simple strategies or rules of thumb and shaped by external environmental factors. And yet these common, less planned, more intuitive decisions often work out well in terms of reproductive success, leading to healthy members of the next generation. This happens despite the great uncertainty that may surround determining who will be a good mate or what is an appropriate way to provision one's children, and without needing to gather a lot of information about the possible courses of action before choosing a mate. In this paper, we outline some of the ways that simple heuristics can be used in making reproductive decisions, and how they can be studied. We begin with an overview of the perspective of ecological rationality within which this research is situated, before proceeding to cover investigations of heuristic rules for mate search and choice, parental provisioning of individual offspring, and decisions related to fertility.This research program on simple heuristics and their effectiveness in appropriate settings represents a new approach to questions in demographics. First, it builds a theoretically motivated, psychologically grounded framework for predicting and understanding population-level patterns of fertility-related behavior, based on the individual-level decision mechanisms that people actually use. Rather than the economists' vision of human decision making employing all of the available information, fully known preferences, and fully processed implications of both, simple heuristics are built on realistic assumptions of the limited information, time, and thinking that people are actually able to bring to bear on most of their choices. Second, this research program uses simulation models of these simple decision heuristics, in conjunction with empirical data from experiments and field observations, to test the effectiveness of the heuristics in different situations and their implications at the population level. …

Herbert Simon’s bounded rationality offers three principles for building a theory of behavior: (i) to study the process of actual decision making (as opposed to as-if models of expected utility maximization), (ii) to study how decisions are made in situations of uncertainty and intractability (as opposed to risk and ambiguity alone), and (iii) to study how minds adapt to environments (as opposed to modeling solely the mind or the environment). Economists hijacked bounded rationality by reinterpreting it to mean optimization under constraints, and psychologists by reinterpreting it as the study of cognitive biases, that is, deviations from optimization. This contradictory double-takeover silenced the revolutionary essence of Simon’s program. My colleagues and I have revived and extended Simon’s lost program, choosing the term ecological rationality to avoid any confusion. As opposed to the cognitive biases program, the study of ecological rationality is both descriptive and prescriptive. It investigates the repertoire of heuristics individuals or institutions have at their disposal (their adaptive toolbox) as well as the conditions under which each heuristic is successful and thus should be used, as measured by real-world criteria (the ecological rationality of heuristics). The study of the adaptive toolbox relies on observation and experimentation; the study of the conditions under which various heuristics should be used relies on mathematical analyses and computer simulations. This combination of descriptive and prescriptive analysis offers a novel perspective for behavioral economics and the study of decision-making in general.

This article reviews how simple heuristics – ‘rules of thumb’ – have guided human adaptation and the evolution of complex cultures. First, we argue that rules of thumb have been important catalysts for the evolution of human knowledge systems in the Holocene past. Through a variety of examples and case studies, we discuss how human cultures have used simple heuristics in domains as diverse as foraging, agriculture, social learning, moral and legal judgement and technological development. We emphasise how rules of thumb are convenient units for cultural transmission, and how they can facilitate efficient decision making by making use of recurrent environmental features. Second, we caution that as Anthropocene environments rapidly change, many traditional heuristic problem-solving strategies will face challenges due to cultural evolutionary mismatch. Old rules may not function in new environments, creating potential challenges for traditional (ecological) knowledge.

Behavioral economists use psychological findings to evaluate and revise economic decision theory, to build models that correspond directly to observations of behavior, and to develop descriptive accounts for deviations from principles of neoclassical rationality. One of the main sources of psychological insight is the heuristics and biases research program. This chapter introduces another source of psychological insights, the ecological rationality of fast-and-frugal heuristics, and is organized as follows. First, the chapter juxtaposes psychological (a la Gigerenzer) with economic (a la Smith) views of ecological rationality, thereby connecting fast-and-frugal heuristics to a major source of inspiration and motivation for behavioral economists, namely experimental economics. Then, it briefly reviews a collection of articles illustrating how the successful use of heuristics in business decision making can be understood by using ecological rationality as an investigative framework. Finally, it locates the field of inquiry for behavioral economics on a continuum of scientific problem solving in the interval that Weaver (1948) called organized complexity. Simple heuristics deserve special attention from behavioral economists because they work best in this very interval where exact methods of optimization are structurally unfitting. Put together, these connections, examples, and arguments suggest that mainstream behavioral economics can gain from integrating this less-explored psychological framework. This integration starts by attempting to formulate effective decision rules as fast-and-frugal heuristics and exploring their ecological rationality.

The Adaptive Toolbox framework specifies heuristics for choice and categorisation that search through cues in previously learned orders (Gigerenzer & Todd, 1999). We examined the learning of three cue parameters defining different orders: discrimination rate (DR) (the probability that a cue points to a unique choice), validity (the probability of correct choice given that a cue discriminates), and success (the probability of correct choice). Success orderings are identical to those by expected information gain (Klayman & Ha, 1987). In two experiments, participants made choices in real-world environments with objective outcome criteria. Participant ratings indicated some appropriate parameter learning when the relevant cue parameter values were highly dispersed. Rated orders of cue validity and DR were less distinct than the objective orders—learning one parameter may be biased towards success by variation in the other. Success ratings capture the variation in validity and DR as well as participants' perception of these parameters.

A notion of rationality represents a structure that can be used to explain, evaluate, and recommend a certain course of action. Full rationality, independent of context, builds such a structure based on the rules of logic and statistical inference. Ecological rationality, on the other hand, focuses on the interaction between the human mind and the task environment. This chapter argues that ecological rationality can provide an operational framework for evolutionary medicine based on compatible foundational concepts. Risk literacy and numeracy methods developed on the basis of an adaptive toolbox approach constitute effective education tools. An evolutionary approach to medical education facilitates the integration of these accessible and well-retained educational tools for physicians and their patients, and can enrich public health policymaking.

Animal foraging routes are analogous to the computationally demanding "traveling salesman problem" (TSP), where individuals must find the shortest path among several locations before returning to the start. Humans approximate solutions to TSPs using simple heuristics or "rules of thumb," but our knowledge of how other animals solve multidestination routing problems is incomplete. Most nonhuman primate species have shown limited ability to route plan. However, captive vervets were shown to solve a TSP for six sites. These results were consistent with either planning three steps ahead or a risk-avoidance strategy. I investigated how wild vervet monkeys (Chlorocebus pygerythrus) solved a path problem with six, equally rewarding food sites; where site arrangement allowed assessment of whether vervets found the shortest route and/or used paths consistent with one of three simple heuristics to navigate. Single vervets took the shortest possible path in fewer than half of the trials, usually in ways consistent with the most efficient heuristic (the convex hull). When in competition, vervets' paths were consistent with different, more efficient heuristics dependent on their dominance rank (a cluster strategy for dominants and the nearest neighbor rule for subordinates). These results suggest that, like humans, vervets may solve multidestination routing problems by applying simple, adaptive, context-specific "rules of thumb." The heuristics that were consistent with vervet paths in this study are the same as some of those asserted to be used by humans. These spatial movement strategies may have common evolutionary roots and be part of a universal mental navigational toolkit. Alternatively, they may have emerged through convergent evolution as the optimal way to solve multidestination routing problems.

O artigo, resultado de uma pesquisa, tem como objetivo contribuir para compreender os desafios atuais para a educação em cidadania e desenvolver instrumentos capazes de ajudar a fazer frente a eles. Relata-se e discute- se o trabalho de duas áreas de estudo atualmente desenvolvidas no Max Planck Institut for Human Development, em Berlim, e a sua contribuição para a formaçãoda cidadania. Uma delas trata da racionalidade ecológica e do uso de heurísticas para a tomada de decisões em um mundo de incertezas. A outra trata da história das emoções, abordando temas como honra, solidariedade e empatia dentro de uma perspectiva histórica e cultural.

Two Types of Ecological Rationality: Or How to Best Combine Psychology and Economics

The evolution of animal communication is a complex issue and one that attracts much research and debate. 'Receiver psychology' has been highlighted as a potential selective force, and we review how avian psychological processes and biases can influence the evolution and design of signals as well as the progress that has been made in testing these ideas in behavioural studies. Interestingly, although birds are a focal group for experimental psychologists and behavioural ecologists alike, the integration of theoretical ideas from psychology into studies of communication has been relatively slow. However, recent operant experiments are starting to address how birds perceive and respond to complex natural signals in an attempt to answer evolutionary problems in communication. This review outlines how a psychological approach to understanding communication is useful, and we hope that it stimulates further research addressing the role of psychological mechanisms in signal evolution.

ObjectiveDecision-making, when providing care and treatment for a person with dementia at the end of life, can be complex and challenging. There is a lack of guidance available to support...

The three previous articles have been devoted to giving a brief description of the theoretical points involved in the development of porcelain. The following articles will briefly describe the actual manufacturing methods and the application of the theoretical points. Recent developments in plant management and control have been applied to porcelain manufacture in the same manner as they have to other industries, and the old rule of thumb and trade secret methods are fast disappearing. Ample storage room for raw materials is necessary for a uniformly high grade product can only be made when there is ample time to test the raw materials prior to using them, and to permit of the rejection of inferior materials when necessary without causing any delays in production. Accurate methods of weighing the various raw materials to form the final raw body are necessary. Care must be used in determining the per cent of moisture in each raw material so as to compound the body on a dry weight basis. The old method of preparing the body by mixing or blunging, with the idea of merely suspending the raw materials in water without regard for grain size is to be avoided. Many potters are now grinding the materials in pebble mills and working to definite grain sizes. The ground body is passed over a magnetic separator to remove magnetic iron, then passed through a fine mesh (120 meshes to the lineal inch) lawn and filter pressed to eliminate excess water, and thus put the ingredients in a workable condition (approximately 22 per cent water). The materials for porcelain can also be stored easily while in this condition. By storage the plasticity is not only increased, but time is available in which to run actual tests on the materials before releasing them for production. The moisture content in filter press cakes is not uniform throughout the cross-section of the cakes. A greater degree of homogeneity is produced by pugging the body after filter pressing. A pug mill develops uniformity to a high degree when properly handled. Several methods of shaping the body into final form require different methods of preparation. Each of these will be described in later issues.

The notion of ecological rationality sees human rationality as the result of the adaptive fit between the human mind and the environment. Ecological rationality focuses the study of decision making on two key questions: First, what are the environmental regularities to which people’s decision strategies are matched, and how frequently do these regularities occur in natural environments? Second, how well can people adapt their use of specific strategies to particular environmental regularities? Research on aging suggests a number of changes in cognitive function, for instance, deficits in learning and memory that may impact decision-making skills. However, it has been shown that simple strategies can work well in many natural environments, which suggests that age-related deficits in strategy use may not necessarily translate into reduced decision quality. Consequently, we argue that predictions about the impact of aging on decision performance depend not only on how aging affects decision-relevant capacities but also on the decision environment in which decisions are made. In sum, we propose that the concept of the ecological rationality is crucial to understanding and aiding the aging decision maker.

Calcium carbonate (CaCO3) scale can form through an "auto-scaling" process in production systems with a CO2-rich environment due to fluid (water/oil/gas) depressurisation. Thermodynamic modelling is used to estimate the amount and severity of CaCO3 scale precipitation in this context in order to design scale inhibitor or other types of treatments. However, field experience has indicated that thermodynamic calculations often lead to an overestimation of the calcite scale problem. One possible source of this discrepancy may be due to kinetic effects; i.e. that the calcite is somewhat oversaturated (Saturation Ratio, SR >1) but the driving force is not sufficiently large and so the deposition is kinetically "slow". The industry response to this situation has been to come up with some simple heuristics based on field observations, and "rules of thumb" have been developed to account for this apparent overestimation of calcite deposition. The central objective of this paper is to try to address the problem of using such an arbitrary field procedure for calcite scale prediction by introducing the kinetics of calcite deposition in a thermodynamically consistent manner. We view the calcite auto-scaling system as one which moves from SR < 1 (non scaling) incrementally to one that is slightly supersaturated (SR slightly > 1). By making the deposition rate a function of SR, this would give slow rate of deposition initially, but as the system moved into the more scaling regime in the production system (SR > 1) then the deposition rate would increase. However, throughout the system, this kinetic formulation must limit correctly (i.e. it must be consistent with) the underlying equilibrium thermodynamics of the full brine/oil/gas system. Thus, we replace the idea of using heuristic estimates of when calcite scaling occurs by one where an estimate (or measurement) of the kinetics is made; indeed, a range of kinetics rates can easily be run to give an envelope of calcite scaling profiles in the wellbore and throughout the production system. In this paper, we present a model that incorporates a fully consistent kinetic formulation into a general thermodynamic scale prediction model. This model can then calculates scaling profiles in production systems considering both kinetic and thermodynamic effects. In particular, a rate law for the precipitation of CaCO3 based on the respective degree of super-saturation is coupled with the Heriot-Watt FAST Scale Prediction model (HW FAST). HW FAST uses the Pitzer equations and the Peng-Robinson Equation of State to model, respectively, the aqueous and hydrocarbon phases (gas and oil), and it has been developed to calculate CaCO3 scaling profiles caused by a de-pressurisation effect in CO2-rich production systems. First, we present an equilibrium thermodynamic example calculation showing that CaCO3 scale precipitates in CO2-rich production systems due to a de-pressurisation effect, and that precipitation is more severe topsides where the pressure is low than it is downhole where the pressure is high. It is explained that the amount of scale precipitated in this auto-scaling process must be plotted as a cumulative amount, in order to avoid the calculation of a potentially misleading scaling profile. This calculation is then repeated, but also considering kinetic effects for systems with varying temperatures and water flowrates. In the example presented here, we show that this system with sufficiently "low" water flowrates can be approximated by a thermodynamic calculation, and that systems with "high water" flowrates must take kinetic effects into consideration. This scaling profile can then be used to more accurately design scale inhibitor treatments, thus avoiding under or over-treatments (e.g. opting for continuous scale inhibitor injection instead of the more expensive squeeze treatment). Our approach focuses on calculating the correct scaling profile in auto-scaling processes, both qualitatively and quantitatively, by coupling a kinetic formulation to a thermodynamic model, and it can be readily extended to other auto-scaling processes. Further, our kinetic model can be easily integrated with commonly available scale prediction software.

The “adaptive toolbox” model of the mind is much too uncritical, even as a model of bounded rationality. There is no place for a “meta-rationality” that questions the shape of the decision-making environments themselves. Thus, using the ABC Group's “fast and frugal heuristics,” one could justify all sorts of conformist behavior as rational. Telling in this regard is their appeal to the philosophical distinction between coherence and correspondence theories of truth.