Agent-based modeling: a new approach for theory building in social psychology.

Most social and psychological phenomena occur not as the result of isolated decisions by individuals but rather as the result of repeated interactions between multiple individuals over time. Yet the theory-building and modeling techniques most commonly used in social psychology are less than ideal for understanding such dynamic and interactive processes. This article describes an alternative approach to theory building, agent-based modeling (ABM), which involves simulation of large numbers of autonomous agents that interact with each other and with a simulated environment and the observation of emergent patterns from their interactions. The authors believe that the ABM approach is better able than prevailing approaches in the field, variable-based modeling (VBM) techniques such as causal modeling, to capture types of complex, dynamic, interactive processes so important in the social world. The article elaborates several important contrasts between ABM and VBM and offers specific recommendations for learning more and applying the ABM approach.     

The growth of developmental thought: Implications for a new evolutionary psychology

Evolution has come to be increasingly discussed in terms of changes in developmental processes rather than simply in terms of changes in gene frequencies. This shift is based in large part on the recognition that since all phenotypic traits arise during ontogeny as products of individual development, a primary basis for evolutionary change must be variations in the patterns and processes of development. Further, the products of development are epigenetic, not just genetic, and this is the case even when considering the evolutionary process. These insights have led investigators to reconsider the established notion of genes as the primary cause of development, opening the door to research programs focused on identifying how genetic and non-genetic factors coact to guide and constrain the process of development and its outcomes. I explore this growth of developmental thought and its implications for the achievement of a unified theory of heredity, development, and evolution and consider its implications for the realization of a new, developmentally based evolutionary psychology.     

Building an integrated positive psychology

The recent emphasis on positive psychology is welcome, and has spurred much relevant research. But, there are still many unresolved conceptual and research issues, which seem to be increasing rather than decreasing. This highlights the importance of conceptually more detailed and comprehensive approaches, so that development of the field can be hastened by addressing emerging issues definitively. The present paper outlines a potentially useful conceptual approach. The paper concludes with a call for issue-resolving research through which orientations and actions proposed as part of positive psychology can be compared in their contributions to performance and health.     

Young children combine sensory cues with learned information in a statistically efficient manner: But task complexity matters

Human adults are adept at mitigating the influence of sensory uncertainty on task performance by integrating sensory cues with learned prior information, in a Bayes‐optimal fashion. Previous research has shown that young children and infants are sensitive to environmental regularities, and that the ability to learn and use such regularities is involved in the development of several cognitive abilities. However, it has also been reported that children younger than 8 do not combine simultaneously available sensory cues in a Bayes‐optimal fashion. Thus, it remains unclear whether, and by what age, children can combine sensory cues with learned regularities in an adult manner. Here, we examine the performance of 6‐ to 7‐year‐old children when tasked with localizing a ‘hidden’ target by combining uncertain sensory information with prior information learned over repeated exposure to the task. We demonstrate that 6‐ to 7‐year‐olds learn task‐relevant statistics at a rate on par with adults, and like adults, are capable of integrating learned regularities with sensory information in a statistically efficient manner. We also show that variables such as task complexity can influence young children's behavior to a greater extent than that of adults, leading their behavior to look sub‐optimal. Our findings have important implications for how we should interpret failures in young children's ability to carry out sophisticated computations. These ‘failures’ need not be attributed to deficits in the fundamental computational capacity available to children early in development, but rather to ancillary immaturities in general cognitive abilities that mask the operation of these computations in specific situations.     

Personality psychology as the integrative study of traits and worldviews

Personality psychology inevitably studies human beings not just as mechanical systems, but also as rational agents, whose experiences and actions are imbued with meaning. The purpose of this paper is to clarify the implications of taking this core element of personality psychology seriously, and to thereby contribute to the development of an integrative and normative framework for the field. I argue that personality can be studied both through trait constructs, referring to objective behavioral regularities, and through worldview constructs, referring to subjective sources of meaning, and try to show that worldviews are, contrary to popular belief, not inherently less universal, or in other ways less basic, than traits. I conclude by emphasizing the importance of more systematic study of worldviews, integration across the trait-worldview divide, and complementing the individual differences approach with personalistic methodology, for the development of richer and more unified portraits of personalities.     

Ceteris Paribus — An Inadequate Representation For Biological Contingency

It has been claimed that ceteris paribus laws, rather than strict laws are the proper aim of the special sciences. This is so because the causal regularities found in these domains are exception-ridden, being contingent on the presence of the appropriate conditions and the absence of interfering factors. I argue that the ceteris paribus strategy obscures rather than illuminates the important similarities and differences between representations of causal regularities in the exact and inexact sciences. In particular, a detailed account of the types and degrees of contingency found in the domain of biology permits a more adequate understanding of the relations among the sciences. This revised version was published online in July 2006 with corrections to the Cover Date.     

Post‐truth politics and discursive psychology

This article argues for the potential of discursive psychology (DP) in the study of post‐truth politics. Work produced outside of psychology is considered, particularly from political science and international relations, which have made a promising start. Providing an overview of this body of research, I argue for their respective strengths and weaknesses. The literature so far tends to work with the notion that truth and emotion are matters that are, or at least should be, distinguishable. Instead, I argue that, rather than lament the blurring between truth and untruth, one should look to how these unfold as matters of practical concern in political discourse. DP is a tool particularly suited to the task; it highlights the importance of viewing ‘truth’ as a rhetorical resource. In this light, we can view post‐truth politics as a rhetorical matter rather than a degeneration of truth.     

Genetics and educational psychology

Background: Molecular genetics, one of the most energetic and exciting areas of science, is slowly but surely coming to educational psychology. Aims: We review recent molecular genetic research on learning disabilities as a sign of things to come in educational psychology. We also consider some misconceptions about genetics that have slowed the acceptance of genetics in educational psychology. Samples: Diverse samples of children with learning disabilities have been studied, primarily in the UK and the USA. Methods: Linkage analysis can detect genes that have large effects on learning disabilities. Association analysis can detect genes of much smaller effect size, which is important because common disorders such as learning disabilities are likely to be influenced by many genes as well as by many environmental factors. Results: For reading disability, replicated linkages have been identified on chromosomes 6, 15 and 18. A gene responsible for a rare type of language impairment has recently been identified. For common language impairment, linkages on chromosomes 16 and 19 have recently been reported. More than 200 genetic disorders, most extremely rare, include mental retardation among their symptoms, and chromosomal abnormalities are a major cause of mental retardation. Conclusions: Although finding specific genes associated with learning disabilities is unlikely to have much of a direct application for teachers in the classroom, such findings will have far‐reaching implications for diagnosis, treatment and prevention of learning disabilities and for research in educational psychology. Educational psychology has been slower to accept evidence for the importance of genetics than other areas of psychology in part because of misconceptions about what it means to say that genetics is important for common complex disorders such as learning disabilities.     

Implicit memory influences the allocation of attention in visual cortex

The visual environment is highly regular, with particular objects frequently appearing in specific locations. Previous studies of visual search have shown that people take advantage of such regularities, detecting targets more quickly when they appear at a predictable location within a given spatial configuration. Moreover, this effect depends on implicit rather than explicit memory for the configurations. These studies have suggested that implicit long-term memory for contextual information influences the allocation of attention, modulating the flow of information through visual cortex. The present study used event-related potentials to provide the first direct support for this proposal. We suggest that this guidance of attention by implicit memory is important in the natural environment because it allows environmental regularities to influence perception without the intervention of limited-capacity conscious processes.     

Differences in the Manifest Dream Content of Anglo-American,Mexican-American,and African-American College Women

This study compares the manifest dream content of African-American college women with that of their Anglo-American and Mexican-American peers. The dream elements examined are characters, emotions, environmental press, achievement outcomes, and social interactions that are aggressive, friendly, or sexual. The results show a statistically significant difference on only one measure: environmental press. That is, the dreams of African Americans reveal a significantly stronger perception of themselves as victims of their fate rather than directors of it.     

A general account of selection: biology, immunology, and behavior.

Authors frequently refer to gene-based selection in biological evolution, the reaction of the immune system to antigens, and operant learning as exemplifying selection processes in the same sense of this term. However, as obvious as this claim may seem on the surface, setting out an account of "selection" that is general enough to incorporate all three of these processes without becoming so general as to be vacuous is far from easy. In this target article, we set out such a general account of selection to see how well it accommodates these very different sorts of selection. The three fundamental elements of this account are replication, variation, and environmental interaction. For selection to occur, these three processes must be related in a very specific way. In particular, replication must alternate with environmental interaction so that any changes that occur in replication are passed on differentially because of environmental interaction. One of the main differences among the three sorts of selection that we investigate concerns the role of organisms. In traditional biological evolution, organisms play a central role with respect to environmental interaction. Although environmental interaction can occur at other levels of the organizational hierarchy, organisms are the primary focus of environmental interaction. In the functioning of the immune system, organisms function as containers. The interactions that result in selection of antibodies during a lifetime are between entities (antibodies and antigens) contained within the organism. Resulting changes in the immune system of one organism are not passed on to later organisms. Nor are changes in operant behavior resulting from behavioral selection passed on to later organisms. But operant behavior is not contained in the organism because most of the interactions that lead to differential replication include parts of the world outside the organism. Changes in the organism's nervous system are the effects of those interactions. The role of genes also varies in these three systems. Biological evolution is gene-based (i.e., genes are the primary replicators). Genes play very different roles in operant behavior and the immune system. However, in all three systems, iteration is central. All three selection processes are also incredibly wasteful and inefficient. They can generate complexity and novelty primarily because they are so wasteful and inefficient.     

Group life shapes the psychology and biology of health: The case for a sociopsychobio model

Engel presented a compelling case for a biopsychosocial model of health. This challenged a biomedical model that he saw as reductionistic, physicalistic, and exclusionist. Yet despite its laudable goals and popularity, the biopsychosocial model can be faulted for being incremental, imprecise, and individualistic. Ultimately, this means it is no less reductionist than the biomedical model which it sought to supplant. In this paper, we present a reformulation of this model that foregrounds the capacity for social groups—and the social contexts in which those groups are embedded—to structure psychology and, through this, biology and health. This sociopsychobio model argues that the three elements of Engel's framework are not fixed and immutable but rather dynamic and interdependent. The model is consistent with a range of recent approaches to health that have focused on the important role that social class, social inequality, social structure, and social networks play in shaping health outcomes. In this paper, though, the concrete value of this reformulation is illustrated through a discussion of recent research that focuses on the role of group memberships and associated social identities in shaping the psychology and biology of stress. This review underlines two key points that are central to the general case for a sociopsychobio model of health. First, that groups are a force in the world that shape the psychology and biology of their members (as well as members of other groups) in ways that cannot be reduced to those group members' functioning as individuals. Second, that groups provide their members with a basis for seeking to change the world rather than simply accepting it. In this, group life is not merely an appendage to psychology and biology but is instead a basis for collective experiences that have the potential to unleash new expressions of both.     

New application of psychology to law: Improving forensic evidence and expert witness contributions

Psychology has made a tremendous contribution to law by showing the malleability of eyewitness perception and memory, and developing best practices for obtaining eyewitness identifications. We suggest that even expert scientific witnesses, which the court heavily relies on as objective and impartial, are also susceptible to bias from various psychological influences. For example, forensic examiners’ interactions with detectives and exposure to information about the case can bias their judgments. We discuss the ten commentaries on these issues across a range of forensic science domains, and affirm what reforms are needed.     

On the Universality of Human Nature and the Uniqueness of the Individual: The Role of Genetics and Adaptation

The concept of a universal human nature, based on a species-typical collection of complex psychological adaptations, is defended as valid, despite the existence of substantial genetic variation that makes each human genetically and biochemically unique. These apparently contradictory facts can be reconciled by considering that (a) complex adaptations necessarily require many genes to regulate their development, and (b) sexual recombination makes it improbable that all the necessary genes for a complex adaptation would be together at once in the same individual, if genes coding for complex adaptations varied substantially between individuals. Selection, interacting with sexual recombination, tends to impose relative uniformity at the functional level in complex adaptive designs, suggesting that most heritable psychological differences are not themselves likely to be complex psychological adaptations. Instead, they are mostly evolutionary by-products, such as concomitants of parasite-driven selection for biochemical individuality. An evolutionary approach to psychological variation reconceptualizes traits as either the output of species-typical, adaptively designed development and psychological mechanisms, or as the result of genetic noise creating perturbations in these mechanisms.     

Dopamine and serotonin systems modify environmental effects on human behavior: A review

The relative influences of genetic and environmental factors in the development of human behavior have been a long‐term topic for an intense debate. Recent behavioral genetic studies suggest focusing on the joint effect of genes and environment, and especially on the life‐course developmental interplay between nature and nurture. Vulnerability to environmental adversities and sensitivity to its benefits may be conditional on genetic background, and regarding psychological outcomes, these kinds of gene × environment interactions may be of higher importance than direct gene–trait associations. In our recent series of studies, we have shown that different variants of serotonergic and dopaminergic genes may moderate the influence of environmental conditions on a range of psychological outcomes, i.e. temperament, depression, hostility, and educational attainment. These studies suggest that depending on their genotype, people may be differentially sensitive to the environmental conditions they encounter. In the light of these results it seems highly plausible that the effects of genes may become evident only when studied in the context of environmental factors.     

Regularities of the physical world and the absence of their internalization

The notion of internalization put forth by Roger Shepard continues to be appealing and challenging. He suggests that we have internalized, during our evolutionary development, environmental regularities, or constraints. Internalization solves one of the hardest problems of perceptual psychology: the underspecification problem. That is the problem of how well-defined perceptual experience is generated from the often ambiguous and incomplete sensory stimulation. Yet, the notion of internalization creates new problems that may outweigh the solution of the underspecification problem. To support this claim, I first examine the concept of internalization, breaking it down into several distinct interpretations. These range from well-resolved dynamic regularities to ill-resolved statistical regularities. As a function of the interpretation the researcher selects, an empirical test of the internalization hypothesis may be straightforward or it may become virtually impossible. I then attempt to cover the range of interpretations by drawing on examples from different domains of visual event perception. Unfortunately, the experimental tests regarding most candidate regularities, such as gravitational acceleration, fail to support the concept of internalization. This suggests that narrow interpretations of the concept should be given up in favor of more abstract interpretations. However, the latter are not easily amenable to empirical testing. There is nonetheless a way to test these abstract interpretations by contrasting internalization with the opposite concept: externalization of body dynamics. I summarize evidence for such a projection of body constraints onto external objects. Based on the combined evidence of well-resolved and ill-resolved regularities, the value of the notion of internalization has to be reassessed.     

On the law of Regular Minimality: Reply to Ennis

Ennis's critique touches on issues important for psychophysics, but the points he makes against the hypothesis that Regular Minimality is a basic property of sensory discrimination are not tenable.(1) Stimulus variability means that one and the same apparent stimulus value (as measured by experimenter) is a probabilistic mixture of true stimulus values. The notion of a true stimulus value is a logical necessity: variability and distribution presuppose the values that vary and are distributed (even if these values are represented by processes or sets rather than real numbers). Regular Minimality is formulated for true stimulus values. That a mixture of probabilities satisfying Regular Minimality does not satisfy this principle (unless it also satisfies Constant Self-Similarity) is an immediate consequence of my 2003 analysis. Stimulus variability can be controlled or estimated: the cases when observed violations of Regular Minimality can be accounted for by stimulus variability corroborate rather than falsify this principle. In this respect stimulus variability is no different from fatigue, perceptual learning, and other factors creating mixtures of discrimination probabilities in an experiment.(2) Could it be that well-behaved Thurstonian-type models are true models of discrimination but their parameters are so adjusted that the violations of Regular Minimality they lead to (due to my 2003 theorems) are too small to be detected experimentally? This is possible, but this amounts to admitting that Regular Minimality is a law after all, albeit only approximate: nothing in the logic of the Thurstonian-type representations per se prevents them from violating Regular Minimality grossly rather than slightly. Moreover, even very small violations predicted by a given class of Thurstonian-type models can be tested in specially designed experiments (perhaps under additional, independently testable assumptions). The results of one such experiment, in which observers were asked to alternately adjust to each other the values of stimuli in two observation areas, indicate that violations of Regular Minimality, if any, are far below limits of plausible interpretability.     

Development itself is the key to understanding developmental disorders

It is a truism that development involves contributions from both genes and environment, but theories differ with respect to the roles they attribute to each, which deeply affects the ways in which developmental disorders are researched. The strict nativist approach to abnormal phenotypes, inspired by adult neuropsychology and evolutionary psychology, seeks to identify impairments to domain-specific cognitive modules and studies the purported juxtaposition of impaired and intact abilities. The neuroconstructivist approach differs in several respects: (i) it seeks more indirect, lower-level causes of abnormality than impaired cognitive modules; (ii)modules are thought to emerge from a developmental process of modularization; (iii) unlike empiricism, neuroconstructivism accepts some form of innately specified starting points, but unlike nativism, these are considered to be initially `domain-relevant', only becoming domain-specific with the process of development and specific environmental interactions; and (iv) different cognitive disorders are considered to lie on a continuum rather than to be truly specific. These alternative theoretical positions are briefly considered as they apply to Specific Language Impairment, and followed by a more detailed case study of a well-defined neurodevelopmental disorder, Williams syndrome. It is argued that development itself plays a crucial role in phenotypical outcomes.     

Beyond the group mind: a quantitative review of the interindividual-intergroup discontinuity effect

This quantitative review of 130 comparisons of interindividual and intergroup interactions in the context of mixed-motive situations reveals that intergroup interactions are generally more competitive than interindividual interactions. The authors identify 4 moderators of this interindividual-intergroup discontinuity effect, each based on the theoretical perspective that the discontinuity effect flows from greater fear and greed in intergroup relative to interindividual interactions. Results reveal that each moderator shares a unique association with the magnitude of the discontinuity effect. The discontinuity effect is larger when (a) participants interact with an opponent whose behavior is unconstrained by the experimenter or constrained by the experimenter to be cooperative rather than constrained by the experimenter to be reciprocal, (b) group members make a group decision rather than individual decisions, (c) unconstrained communication between participants is present rather than absent, and (d) conflict of interest is severe rather than mild.     

Gender and Group Process: A Developmental Perspective

Until recently, the study of gender development has focused mainly on sex typing as an attribute of the individual. Although this perspective continues to be enlightening, recent work has focused increasingly on children's tendency to congregate in same-sex groups. This self-segregation of the two sexes implies that much of childhood gender enactment occurs in the context of same-sex dyads or larger groups. There are emergent properties of such groups, so that certain sex-distinctive qualities occur at the level of the group rather than at the level of the individual. There is increasing research interest in the distinctive nature of the group structures, activities, and interactions that typify all-male as compared with all-female groups, and in the socialization that occurs within these groups. Next steps in research will surely call for the integration of the individual and group perspectives.