Annual Review of Psychology - Volume 72, 2021

Over the past century, psychologists have discussed whether forgetting might arise from active mechanisms that promote memory loss to achieve various functions, such as minimizing errors, facilitating learning, or regulating one's emotional state. The past decade has witnessed a great expansion in knowledge about the brain mechanisms underlying active forgetting in its varying forms. A core discovery concerns the role of the prefrontal cortex in exerting top-down control over mnemonic activity in the hippocampus and other brain structures, often via inhibitory control. New findings reveal that such processes not only induce forgetting of specific memories but also can suppress the operation of mnemonic processes more broadly, triggering windows of anterograde and retrograde amnesia in healthy people. Recent work extends active forgetting to nonhuman animals, presaging the development of a multilevel mechanistic account that spans the cognitive, systems, network, and even cellular levels. This work reveals how organisms adapt their memories to their cognitive and emotional goals and has implications for understanding vulnerability to psychiatric disorders.

Behavior genetics studies how genetic differences among people contribute to differences in their psychology and behavior. Here, I describe how the conclusions and methods of behavior genetics have evolved in the postgenomic era in which the human genome can be directly measured. First, I revisit the first law of behavioral genetics stating that everything is heritable, and I describe results from large-scale meta-analyses of twin data and new methods for estimating heritability using measured DNA. Second, I describe new methods in statistical genetics, including genome-wide association studies and polygenic score analyses. Third, I describe the next generation of work on gene × environment interaction, with a particular focus on how genetic influences vary across sociopolitical contexts and exogenous environments. Genomic technology has ushered in a golden age of new tools to address enduring questions about how genes and environments combine to create unique human lives.

The study of motor planning and learning in humans has undergone a dramatic transformation in the 20 years since this journal's last review of this topic. The behavioral analysis of movement, the foundational approach for psychology, has been complemented by ideas from control theory, computer science, statistics, and, most notably, neuroscience. The result of this interdisciplinary approach has been a focus on the computational level of analysis, leading to the development of mechanistic models at the psychological level to explain how humans plan, execute, and consolidate skilled reaching movements. This review emphasizes new perspectives on action selection and motor planning, research that stands in contrast to the previously dominant representation-based perspective of motor programming, as well as an emerging literature highlighting the convergent operation of multiple processes in sensorimotor learning.

The development of the use of transcranial magnetic stimulation (TMS) in the study of psychological functions has entered a new phase of sophistication. This is largely due to an increasing physiological knowledge of its effects and to its being used in combination with other experimental techniques. This review presents the current state of our understanding of the mechanisms of TMS in the context of designing and interpreting psychological experiments. We discuss the major conceptual advances in behavioral studies using TMS. There are meaningful physiological and technical achievements to review, as well as a wealth of new perceptual and cognitive experiments. In doing so we summarize the different uses and challenges of TMS in mental chronometry, perception, awareness, learning, and memory.

The memories that we retain can serve many functions. They guide our future actions, form a scaffold for constructing the self, and continue to shape both the self and the way we perceive the world. Although most memories we acquire each day are forgotten, those integrated within the structure of multiple prior memories tend to endure. A rapidly growing body of research is steadily elucidating how the consolidation of memories depends on their reactivation during sleep. Processing memories during sleep not only helps counteract their weakening but also supports problem solving, creativity, and emotional regulation. Yet, sleep-based processing might become maladaptive, such as when worries are excessively revisited. Advances in research on memory and sleep can thus shed light on how this processing influences our waking life, which can further inspire the development of novel strategies for decreasing detrimental rumination-like activity during sleep and for promoting beneficial sleep cognition.

Human memory, as a product of the mind and brain, is inherently private and personal. Yet, arising from the interaction between the organism and its ecology in the course of phylogeny and ontogeny, human memory is also profoundly collective and cultural. In this review, I discuss the cultural foundation of human memory. I start by briefly reflecting on the conception of memory against a historical and cultural background. I then detail a model of a culturally saturated mnemonic system in which cultural elements constitute and condition various processes of remembering, focusing on memory representation, perceptual encoding, memory function, memory reconstruction, memory expression, and memory socialization. Then I discuss research on working memory, episodic memory, and autobiographical memory as examples that further demonstrate how cultural elements shape the processes and consequences of remembering and lay the foundation for human memory. I conclude by outlining some important future directions in memory research.

To explain trade-offs in choice, researchers have proposed myriad phenomena and decision rules, each paired with separate theories and idiosyncratic vocabularies. Yet most choice problems are ultimately resolved with one of just two types of solutions: mixed or extreme. For example, people adopt mixed solutions for resolving trade-offs when they allow exercising to license indulgence afterward (balancing between goals), read different literary genres (variety seeking), and order medium-sized coffees (the compromise effect). By contrast, when people adopt extreme solutions for resolving these exact same trade-offs, they exhibit highlighting, consistency seeking, and compromise avoidance, respectively. Our review of the choice literature first illustrates how many seemingly unrelated phenomena actually share the same underlying psychology. We then identify variables that promote one solution versus the other. These variables, in turn, systematically influence which of opposite choice effects arise (e.g., highlighting versus balancing). Finally, we demonstrate how several mistakes people purport to make can potentially instead be reinterpreted as mixed solutions for resolving trade-offs. We conclude with guidance for distinguishing mistakes from mixed solutions.

Humans are an ultrasocial species. This sociality, however, cannot be fully explained by the canonical approaches found in evolutionary biology, psychology, or economics. Understanding our unique social psychology requires accounting not only for the breadth and intensity of human cooperation but also for the variation found across societies, over history, and among behavioral domains. Here, we introduce an expanded evolutionary approach that considers how genetic and cultural evolution, and their interaction, may have shaped both the reliably developing features of our minds and the well-documented differences in cultural psychologies around the globe. We review the major evolutionary mechanisms that have been proposed to explain human cooperation, including kinship, reciprocity, reputation, signaling, and punishment; we discuss key culture–gene coevolutionary hypotheses, such as those surrounding self-domestication and norm psychology; and we consider the role of religions and marriage systems. Empirically, we synthesize experimental and observational evidence from studies of children and adults from diverse societies with research among nonhuman primates.

Social groups are a pervasive feature of human life. One factor that is often understudied in the literature on person perception and social categorization is language. Yet, someone's language (and accent) provides a tremendous amount of social information to a listener. Disciplines across the social and behavioral sciences—ranging from linguistics to anthropology to economics—have exposed the social significance of language. Less social psychological research has historically focused on language as a vehicle for social grouping. Yet, new approaches in psychology are reversing this trend. This article first reviews evidence, primarily from psycholinguistics, documenting how speech provides social information. Next it turns to developmental psychology, showing how young humans begin to see others’ language as conveying social group information. It then explores how the tendency to see language as a social cue has vast implications for people's psychological processes (e.g., psychological essentialism and trust) and also for society, including education and the law.

In this review we bring a psychological perspective to the issue of intergenerational economic mobility. More specifically, we present a new dual developmental science framework to consider the educational outcomes of parents and children together in order to foster economic mobility. We focus on two key populations: children in early childhood (from birth to age 6) and parents in early adulthood (in their 20s and early 30s). We posit that mastery of three sets of developmental tasks for each generation—academic/language skills, self-regulation/mental health, and parent-child relationship—will lead to improved educational outcomes for both. Taken as a whole, the dual developmental science framework integrates theory and research on single-generation development (i.e., children or parents) with dynamic and bidirectional theories about the interdependence of children and parents over time.We conclude the review by evaluating existing education interventions and research using the dual developmental science framework, and we discuss opportunities for innovation.

Research on morality has increased rapidly over the past 10 years. At the center of this research are moral judgments—evaluative judgments that a perceiver makes in response to a moral norm violation. But there is substantial diversity in what has been called moral judgment. This article offers a framework that distinguishes, theoretically and empirically, four classes of moral judgment: evaluations, norm judgments, moral wrongness judgments, and blame judgments. These judgments differ in their typical objects, the information they process, their speed, and their social functions. The framework presented here organizes the extensive literature and provides fresh perspectives on measurement, the nature of moral intuitions, the status of moral dumbfounding, and the prospects of dual-process models of moral judgment. It also identifies omitted questions and sets the stage for a broader theory of moral judgment, which the coming decades may bring forth.

Self-regulation is a core aspect of human functioning that helps facilitate the successful pursuit of personal goals. There has been a proliferation of theories and models describing different aspects of self-regulation both within and outside of psychology. All of these models provide insights about self-regulation, but sometimes they talk past each other, make only shallow contributions, or make contributions that are underappreciated by scholars working in adjacent areas. The purpose of this article is to integrate across the many different models in order to refine the vast literature on self-regulation. To achieve this objective, we first review some of the more prominent models of self-regulation coming from social psychology, personality psychology, and cognitive neuroscience. We then integrate across these models based on four key elements—level of analysis, conflict, emotion, and cognitive functioning—specifically identifying points of convergence but also points of insufficient emphasis. We close with prescriptions for future research.

This review covers theory and research on the psychological characteristics and consequences of attitudes that are experienced as moral convictions, that is, attitudes that people perceive as grounded in a fundamental distinction between right and wrong. Morally convicted attitudes represent something psychologically distinct from other constructs (e.g., strong but nonmoral attitudes or religious beliefs), are perceived as universally and objectively true, and are comparatively immune to authority or peer influence. Variance in moral conviction also predicts important social and political consequences. Stronger moral conviction about a given attitude object, for example, is associated with greater intolerance of attitude dissimilarity, resistance to procedural solutions for conflict about that issue, and increased political engagement and volunteerism in that attitude domain. Finally, we review recent research that explores the processes that lead to attitude moralization; we integrate these efforts and conclude with a new domain theory of attitude moralization.

This chapter reviews research on the group identity explanation of social influence, grounded in self-categorization theory, and contrasts it with other group-based explanations, including normative influence, interdependence, and social network approaches, as well as approaches to persuasion and influence that background group (identity) processes. Although the review primarily discusses recent research, its focus also invites reappraisal of some classic research in order to address basic questions about the scope and power of the group identity explanation. The self-categorization explanation of influence grounded in group norms, moderated by group identification, is compared and contrasted to other normative explanations of influence, notably the concept of injunctive norms and the relation to moral conviction. A range of moderating factors relating to individual variation, features of the intragroup and intergroup context, and important contextual variables (i.e., anonymity versus visibility, isolation versus copresence) that are particularly relevant to online influence in the new media are also reviewed.

The ways that couples form and manage their intimate relationships at higher and lower levels of socioeconomic status (SES) have been diverging steadily over the past several decades. At higher SES levels, couples postpone marriage and childbirth to invest in education and careers, but they eventually marry at high rates and have relatively low risk for divorce. At lower SES levels, couples are more likely to cohabit and give birth prior to marriage and less likely to marry at all. This review examines how SES comes to be associated with the formation, development, and dissolution of intimate relationships. Overall, research has highlighted how a couple's socioeconomic context facilitates some choices and constrains others, resulting in different capacities for relationship maintenance and different adaptive mating strategies for more and less advantaged couples. A generalizable relationship science requires research that acknowledges these differences and one that recruits, describes, and attends to socioeconomic diversity across couples.

Experimental games model situations in which the future outcomes of individuals and groups depend on their own choices and on those of other (groups of) individuals. Games are a powerful tool to identify the neural and psychological mechanisms underlying interpersonal and group cooperation and coordination. Here we discuss recent developments in how experimental games are used and adapted, with an increased focus on repeated interactions, partner control through sanctioning, and partner (de)selection for future interactions. Important advances have been made in uncovering the neurobiological underpinnings of key factors involved in cooperation and coordination, including social preferences, cooperative beliefs, (emotion) signaling, and, in particular, reputations and (in)direct reciprocity. Emerging trends at the cross-sections of psychology, economics, and the neurosciences include an increased focus on group heterogeneities, intergroup polarization and conflict, cross-cultural differences in cooperation and norm enforcement, and neurocomputational modeling of the formation and updating of social preferences and beliefs.

The social neuroscience approach to prejudice investigates the psychology of intergroup bias by integrating models and methods of neuroscience with the social psychology of prejudice, stereotyping, and discrimination. Here, we review major contemporary lines of inquiry, including current accounts of group-based categorization; formation and updating of prejudice and stereotypes; effects of prejudice on perception, emotion, and decision making; and the self-regulation of prejudice. In each section, we discuss key social neuroscience findings, consider interpretational challenges and connections with the behavioral literature, and highlight how they advance psychological theories of prejudice. We conclude by discussing the next-generation questions that will continue to guide the social neuroscience approach toward addressing major societal issues of prejudice and discrimination.

Fear of transnational terrorism, along with a revitalization of sectarian nationalism, is sundering social and political consensus across the world. Can psychology help? The focus of this review is on the psychological and related social factors that instigate and sustain violent extremism and polarizing group conflict. I first describe the changing global landscape of transnational terrorism, encompassing mainly violent Islamist revivalism and resurgent racial and ethnic supremacism. Next, I explore the psychosocial nature of the devoted actor and rational actor frameworks, focusing on how sacred values, identity fusion, and social network dynamics motivate and maintain extreme violence. The psychology of the will to fight and die is illustrated in behavioral and brain studies with frontline combatants in Iraq, militant supporters in Morocco, and radicalizing populations in Spain. This is followed by a consideration of how to deal with value-driven conflicts and a discussion of how the Internet and social media encourage the propagation of polarized conflict.

Prejudice and discrimination toward immigrants, and the consequences of these negative attitudes and behavior, are key determinants of the economic, sociocultural, and civic-political future of receiving societies and of the individuals who seek to make these societies their new home. In this article I review and organize the existing literature on the determinants and nature of prejudice and discrimination toward immigrants, summarizing what we know to date and the challenges in attributing effects to immigrant status per se. I also discuss the consequences of discrimination against immigrants for immigrants themselves, their families, and the societies in which they settle. I conclude by presenting key research questions and topics in this domain that should be at the top of the research agenda for those interested in intergroup relations in this age of mass migration.