Short arms and talking eggs: Why we should no longer abide the nativist-empiricist debate

The central role of the individual in the history of brains

Every species' brain, body and behavior is shaped by the contingencies of their evolutionary history; these exert pressures that change their developmental trajectories. There is, however, another set of contingencies that shape us and other animals: those that occur during a lifetime. In this perspective piece, we show how these two histories are intertwined by focusing on the individual. We suggest that organisms--their brains and behaviors--are not solely the developmental products of genes and neural circuitry but individual centers of action unfolding in time. To unpack this idea, we first emphasize the importance of variation and the central role of the individual in biology. We then go over "errors in time" that we often make when comparing development across species. Next, we reveal how an individual's development is a process rather than a product by presenting a set of case studies. These show developmental trajectories as emerging in the contexts of the "the actual now" and "the presence of the past". Our consideration reveals that individuals are slippery-they are never static; they are a set of on-going, creative activities. In light of this, it seems that taking individual development seriously is essential if we aspire to make meaningful comparisons of neural circuits and behavior within and across species.

The key to understanding core knowledge resides in the fetus

What Babies Know outlines a compelling case for why infancy research is fundamental for conceptualizing what it is to be human. There is another period in human development that is relatively inaccessible, yet is more important. In order to truly understand the nature of core knowledge, perception, and cognition, we must start not with the infant, but with the fetus.

The forgotten militant and his enduring mission: Zing-Yang Kuo and his extraordinary years in behavioral neuroembryology (1929-1939)

Zing-Yang Kuo (1898-1970), hailed as China's behaviorist psychologist, earned "Out-Watsons Mr. Watson" in the international anti-instinct movement. His contributions to the field on behavioral neuroembryology (1929-1939) are often overlooked in comparison to his achievements in psychology. We retrieved the titles of all of Kuo's publications from 1929 to 1939 and examined those related to his research on the origins and development of embryonic behavioral ontogeny and the neural basis of embryonic behavior. Remarkably, Kuo concurrently focused on embryos during the same period as North American neuroembryologists. He maintained an independent stance in the debate over the sequence of behavioral ontogeny, represented by the embryonic neuroscientists Coghill and Windle, and critically pointed out limitations in research on both sides of the debate. Drawing from his experiments with chicken embryos, Kuo proposed the theory of behavioral epigenesis, which attempted to end the nature-nurture dichotomy and promote the transformation of the research path of behavioral embryology from elementary physiological anatomy toward a deep "comprehensive science." Kuo's achievements directly laid the foundation for the interdisciplinary field of developmental psychobiology, constructing a new conceptual framework for the systematic analysis of behavioral development and promoting the establishment and development of a new approach to epiphenotype epigenetics.

Explaining First Language Acquisition in Terms of Basic Behavioral Processes: Introduction to the Special Section

This special section of Perspectives on Behavior Science follows up on a virtual panel discussion on the role of operant and Pavlovian processes in children's language learning. We present four articles, including two contributed by panelists, that illustrate the explanatory power of operant conditioning processes in the study of language.

Reexamining developmental continuity and discontinuity in the 21st century: Better aligning behaviors, functions, and mechanisms

Developmental science aims to explain development across the lifespan. Jerome Kagan observed that the same behavior can occur for different reasons, and differing behaviors can occur for the same reason. To help account for persistence, desistence, and transformation of behavior across development, Kagan introduced various types of continuity and discontinuity of forms and functions of behavior. This framework provides opportunities for identifying explanatory mechanisms in behavior development. However, misconceptions remain in applying the concepts that Kagan introduced. Much of the literature assumes developmental continuity in constructs without examining whether assumptions are supported, leading to faulty developmental inferences. For instance, the use of the same measure across time to assess development assumes that the behavior occurs for the same reason across time (homotypic continuity). In addition, just because one behavior predicts a different behavior at a later time does not necessarily indicate that age-differing behaviors occur for the same reason (heterotypic continuity). This review aims to advance conceptualizations of continuity and discontinuity from a contemporary perspective with aims to improve mechanistic understanding of behavior development across the lifespan. To better align behaviors, functions, and mechanisms, research should (a) examine (dis)continuity of individual behaviors rather than merely syndromes, (b) identify the function(s) of the given behavior(s), and (c) identify the cognitive and biological processes that underlie the behavior-function pairs. Incorporating examples from research on development of humans and nonhuman animals, I discuss challenges from work that has followed Kagan's ideas and ways to advance understanding of continuity and discontinuity across development. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Development as explanation: Understanding phenotypic stability and variability after the failure of genetic determinism

In the predominately gene-centered view of 20th century biology, the relationship between genotype and phenotype was essentially a relationship between cause and effect, between a plan and a product. Abandoning the idea of genes as inherited instructions or blueprints for phenotypes raises the question of how to best account for observed phenotypic stability and variability within and across generations of a population. We argue that the processes responsible for phenotypic stability and the processes responsible for phenotypic variability are one and the same, namely, the dynamics of development. This argument proposes that stability of phenotypic form is found not because of the transmission of genotypes, genetic programs, or the transfer of internal blueprints, but because similar internal and external conditions-collectively conceptualized as resources of development-can be reliably reconstituted in each generation. Variability of phenotypic form, which is an indispensable feature of any evolving system, relies on these same resources, but because the internal and external conditions of development are not reconstituted identically in succeeding generations, these conditions-and the phenotypes to which they give rise-will always be characterized by at least some variability.

The acquisition of speech categories: Beyond perceptual narrowing, beyond unsupervised learning and beyond infancy

An early achievement in language is carving a variable acoustic space into categories. The canonical story is that infants accomplish this by the second year, when only unsupervised learning is plausible. I challenge this view, synthesizing five lines of developmental, phonetic and computational work. First, unsupervised learning may be insufficient given the statistics of speech (including infant-directed). Second, evidence that infants "have" speech categories rests on tenuous methodological assumptions. Third, the fact that the ecology of the learning environment is unsupervised does not rule out more powerful error driven learning mechanisms. Fourth, several implicit supervisory signals are available to older infants. Finally, development is protracted through adolescence, enabling richer avenues for development. Infancy may be a time of organizing the auditory space, but true categorization only arises via complex developmental cascades later in life. This has implications for critical periods, second language acquisition, and our basic framing of speech perception.

Working memory development: A 50-year assessment of research and underlying theories

The author has thought about working memory, not always by that name, since 1969 and has conducted research on its infant and child development since the same year that the seminal work of Baddeley and Hitch (1974) was published. The present article assesses how the field of working memory development has been influenced since those years by major theoretical perspectives: empiricism (along with behaviorism), nativism (along with modularity), cognitivism (along with constructivism), and dynamic systems theory. The field has not fully discussed the point that these theoretical perspectives have helped to shape different kinds of proposed working memory systems, which in turn have deeply influenced what is researched and how it is researched. Here I discuss that mapping of theoretical viewpoints onto assumptions about working memory and trace the influence of this mapping on the field of working memory development. I illustrate where these influences have led in my own developmental research program over the years.

A Dynamical Reconceptualization of Executive-Function Development

Executive function plays a foundational role in everyday behaviors across the life span. The theoretical understanding of executive-function development, however, is still a work in progress. Doebel proposed that executive-function development reflects skills using control in the service of behavior-using mental content such as knowledge and beliefs to guide behavior in a context-specific fashion. This liberating view contrasts with modular views of executive function. This new view resembles some older dynamic-systems concepts that long ago proposed that behavior reflects the assembly of multiple pieces in context. We dig into this resemblance and evaluate what else dynamic-systems theory adds to the understanding of executive-function development. We describe core dynamic-systems concepts and apply them to executive function-as conceptualized by Doebel-and through this lens explain the multilevel nature of goal-directed behavior and how a capacity to behave in a goal-directed fashion across contexts emerges over development. We then describe a dynamic systems model of goal-directed behavior during childhood and, finally, address broader theoretical implications of dynamic-systems theory and propose new translational implications for fostering children's capacity to behave in a goal-directed fashion across everyday contexts.

Learning words in space and time: Contrasting models of the suspicious coincidence effect

In their 2007b Psychological Review paper, Xu and Tenenbaum found that early word learning follows the classic logic of the "suspicious coincidence effect:" when presented with a novel name ('fep') and three identical exemplars (three Labradors), word learners generalized novel names more narrowly than when presented with a single exemplar (one Labrador). Xu and Tenenbaum predicted the suspicious coincidence effect based on a Bayesian model of word learning and demonstrated that no other theory captured this effect. Recent empirical studies have revealed, however, that the effect is influenced by factors seemingly outside the purview of the Bayesian account. A process-based perspective correctly predicted that when exemplars are shown sequentially, the effect is eliminated or reversed (Spencer, Perone, Smith, & Samuelson, 2011). Here, we present a new, formal account of the suspicious coincidence effect using a generalization of a Dynamic Neural Field (DNF) model of word learning. The DNF model captures both the original finding and its reversal with sequential presentation. We compare the DNF model's performance with that of a more flexible version of the Bayesian model that allows both strong and weak sampling assumptions. Model comparison results show that the dynamic field account provides a better fit to the empirical data. We discuss the implications of the DNF model with respect to broader contrasts between Bayesian and process-level models.

An Ecological Approach To Learning In (Not And) Development

The ecological approach is a framework for studying the behavior of animals in their environments. My version of an ecological approach focuses on learning in the context of development. I argue that the most important thing animals learn is behavioral flexibility. They must acquire the ability to flexibly guide their behavior from moment to moment in the midst of developmental changes in their bodies, brains, skills, and environments. They must select, modify, and create behaviors appropriate to the current situation. In essence, animals must learn how to learn. I describe the central concepts and empirical strategies for studying learning in development and use examples of infants coping with novel tasks to give a flavor of what researchers know and still must discover about the functions and processes of learning (to learn) in (not and) development.

Rationalization is rare, reasoning is pervasive

If rationalization were ubiquitous, it would undermine a fundamental premise of human discourse. A review of key evidence indicates that rationalization is rare and confined to choices among comparable options. In contrast, reasoning is pervasive in human decision making. Within the constraints of reasoning, rationalization may operate in ambiguous situations. Studying these processes requires careful definitions and operationalizations.

A.R. Luria’s cultural neuropsychology in the 21st century

Luria has long been one of the most influential authors in cognitive neurosciences, in particular in neuropsychology. New scientific advances and clinical observations have confirmed many of his proposals and hypotheses. In this paper one of his major ideas is analyzed: the influence of cultural factors on human cognition. The systemic-dynamic Lurian analysis of brain activity is based on Vygotsky's concept of higher mental functions, which are social in origin and complex and dynamic in their structure. Higher mental functions are based on a complex system of operations and means both external and internal. Living conditions and hence cultural characteristics have dramatically changed during the last half century with the development of new media and new virtual ways of communication. Review of contemporary developments supporting the appropriateness and usefulness of these concepts is presented. It is finally concluded that Luria is one of the major founders of contemporary neuropsychology not only from the clinical point of view, but also from the cultural perspective. His influence has continued undiminished during the 21st century.

Parents Influence the Visual Learning Environment Through Children's Manual Actions

The present research studied children in the second year of life (N = 29, M_age  = 21.14 months, SD = 2.64 months) using experimental manipulations within and between subjects to show that responsive parental influence helps children have more frequent sustained object holds with fewer switches between objects compared to when parents are either not involved or over-involved. Regardless of parental involvement, sustained holds were visually rich, based on the size, centeredness, and dominance of the held object relative to other objects. These findings are important because they suggest not only that the child's body creates visually rich scenes across play contexts but also that a responsive parent can increase the frequency of these visually rich and informative moments.

Violations of Core Knowledge Shape Early Learning

Research on cognitive development has revealed that even the youngest minds detect and respond to events that adults find surprising. These surprise responses suggest that infants have a basic set of "core" expectations about the world that are shared with adults and other species. However, little work has asked what purpose these surprise responses serve. Here we discuss recent evidence that violations of core knowledge offer special opportunities for learning. Infants and young children make predictions about the world on the basis of their core knowledge of objects, quantities, and social entities. We argue that when these predictions fail to match the observed data, infants and children experience an enhanced drive to seek and retain new information. This impact of surprise on learning is not equipotent. Instead, it is directed to entities that are relevant to the surprise itself; this drive propels children-even infants-to form and test new hypotheses about surprising aspects of the world. We briefly consider similarities and differences between these recent findings with infants and children, on the one hand, and findings on prediction errors in humans and non-human animals, on the other. These comparisons raise open questions that require continued inquiry, but suggest that considering phenomena across species, ages, kinds of surprise, and types of learning will ultimately help to clarify how surprise shapes thought.

The Science of Early Moral Development: on Defining, Constructing, and Studying Morality from Birth

The first 4 years of moral development are perhaps the most transformative. Helpless neonates become infants who routinely help and harm others; infants develop into preschoolers who make moral judgments based on moral concerns with welfare. Over the past two decades, there has been tremendous empirical progress, but also theoretical stalemates, in research on early moral development. To advance the field, this chapter argues for providing definitions of key terms, adopting an interactionist and constructivist approach (eschewing the dichotomy between innate and learned characteristics), and combining naturalistic and experimental methods. On this basis, the chapter reviews research on how children's orientations toward helping and harming others develop gradually through everyday social interactions in the early years. In these interactions, children play active roles through initiation, negotiation, protest, and construction. The chapter concludes with key questions for future research on early moral development.

New Beginnings: An Interactionist and Constructivist Approach to Early Moral Development

Orientations toward harming and helping others are central to morality. These orientations undergo major transformations in early life. This paper proposes an interactionist and constructivist approach to early moral development, and discusses how children construct orientations toward harming and helping through everyday social interactions. A major developmental acquisition - typically evident by age three - is the ability to make judgments of right and wrong based on concerns with others' welfare. The paper concludes by outlining issues for future research on the development of morality from infancy to childhood.

A Developmental Perspective on the Origins of Morality in Infancy and Early Childhood

Key constituents of morality emerge during the first 4 years of life. Recent research with infants and toddlers holds a promise to explain the origins of human morality. This article takes a constructivist approach to the acquisition of morality, and makes three main proposals. First, research on moral development needs an explicit definition of morality. Definitions are crucial for scholarly communication and for settling empirical questions. Second, researchers would benefit from eschewing the dichotomy between innate and learned explanations of morality. Based on work on developmental biology, we propose that all developmental transitions involve both genetic and environmental factors. Third, attention is needed to developmental changes, alongside continuities, in the development of morality from infancy through childhood. Although infants and toddlers show behaviors that resemble the morally relevant behaviors of older children and adults, they do not judge acts as morally right or wrong until later in childhood. We illustrate these points by discussing the development of two phenomena central to morality: Orientations toward helping others and developing concepts of social equality. We assert that a constructivist approach will help to bridge research on infants and toddlers with research on moral developmental later in childhood and into adulthood.

New Frontiers in Language Evolution and Development

This article introduces the Special Issue and its focus on research in language evolution with emphasis on theory as well as computational and robotic modeling. A key theme is based on the growth of evolutionary developmental biology or evo-devo. The Special Issue consists of 13 articles organized in two sections: A) Theoretical foundations and B) Modeling and simulation studies. All the papers are interdisciplinary in nature, encompassing work in biological and linguistic foundations for the study of language evolution as well as a variety of computational and robotic modeling efforts shedding light on how language may be developed and may have evolved.

When the Sound Becomes the Goal. 4E Cognition and Teleomusicality in Early Infancy

In this paper we explore early musical behaviors through the lenses of the recently emerged "4E" approach to mind, which sees cognitive processes as Embodied, Embedded, Enacted, and Extended. In doing so, we draw from a range of interdisciplinary research, engaging in critical and constructive discussions with both new findings and existing positions. In particular, we refer to observational research by French pedagogue and psychologist François Delalande, who examined infants' first "sound discoveries" and individuated three different musical "conducts" inspired by the "phases of the game" originally postulated by Piaget. Elaborating on such ideas we introduce the notion of "teleomusicality," which describes the goal-directed behaviors infants adopt to explore and play with sounds. This is distinguished from the developmentally earlier "protomusicality," which is based on music-like utterances, movements, and emotionally relevant interactions (e.g., with primary caregivers) that do not entail a primary focus on sound itself. The development from protomusicality to teleomusicality is discussed in terms of an "attentive shift" that occurs between 6 and 10 months of age. This forms the basis of a conceptual framework for early musical development that emphasizes the emergence of exploratory, goal-directed (i.e., sound-oriented), and self-organized musical actions in infancy. In line with this, we provide a preliminary taxonomy of teleomusical processes discussing "Original Teleomusical Acts" (OTAs) and "Constituted Teleomusical Acts" (CTAs). We argue that while OTAs can be easily witnessed in infants' exploratory behaviors, CTAs involve the mastery of more specific and complex goal-directed chains of actions central to musical activity.

Word learning mechanisms

How do children acquire the meanings of words? Many word learning mechanisms have been proposed to guide learners through this challenging task. Despite the availability of rich information in the learner's linguistic and extralinguistic input, the word-learning task is insurmountable without such mechanisms for filtering through and utilizing that information. Different kinds of words, such as nouns denoting object concepts and verbs denoting event concepts, require to some extent different kinds of information and, therefore, access to different kinds of mechanisms. We review some of these mechanisms to examine the relationship between the input that is available to learners and learners' intake of that input-that is, the organized, interpreted, and stored representations they form. We discuss how learners segment individual words from the speech stream and identify their grammatical categories, how they identify the concepts denoted by these words, and how they refine their initial representations of word meanings. WIREs Cogn Sci 2017, 8:e1435. doi: 10.1002/wcs.1435 This article is categorized under: Linguistics > Language Acquisition Psychology > Language.

Ecological Commitments: Why Developmental Science Needs Naturalistic Methods

Much of developmental science aims to explain how or whether children's experiences influence their thoughts and actions. Developmental theories make assumptions and claims-what I call ecological commitments-about events outside research contexts. In this article, I argue that most developmental theories make ecological commitments about children's thoughts, actions, and experiences outside research contexts, and that these commitments sometimes go unstated and untested. I also argue that naturalistic methods can provide evidence for or against ecological commitments, and that naturalistic and experimental studies address unique yet complementary questions. Rather than argue for increasing the ecological validity of experiments or abandoning laboratory research, I propose reconsidering the relations among developmental theories, naturalistic methods, and laboratory experiments.

Applications of Dynamic Systems Theory to Cognition and Development: New Frontiers

A central goal in developmental science is to explain the emergence of new behavioral forms. Researchers consider potential sources of behavioral change depending partly on their theoretical perspective. This chapter reviews one perspective, dynamic systems theory, which emphasizes the interactions among multiple components to drive behavior and developmental change. To illustrate the central concepts of dynamic systems theory, we describe empirical and computational studies from a range of domains, including motor development, the Piagetian A-not-B task, infant visual recognition, visual working memory capacity, and language learning. We conclude by advocating for a broader application of dynamic systems approaches to understanding cognitive and behavioral development, laying out the remaining barriers we see and suggested ways to overcome them.

What does it take to learn a word?

Vocabulary learning is deceptively hard, but toddlers often make it look easy. Prior theories proposed that children's rapid acquisition of words is based on language-specific knowledge and constraints. In contrast, more recent work converges on the view that word learning proceeds via domain-general processes that are tuned to richly structured-not impoverished-input. We argue that new theoretical insights, coupled with methodological tools, have pushed the field toward an appreciation of simple, content-free processes working together as a system to support the acquisition of words. We illustrate this by considering three central phenomena of early language development: referential ambiguity, fast-mapping, and the vocabulary spurt. WIREs Cogn Sci 2017, 8:e1421. doi: 10.1002/wcs.1421 For further resources related to this article, please visit the WIREs website.

Development evolving: the origins and meanings of instinct

How do migratory birds, herding dogs, and navigating sea turtles do the amazing things that they do? For hundreds of years, scientists and philosophers have struggled over possible explanations. In time, one word came to dominate the discussion: instinct. It became the catch-all explanation for those adaptive and complex abilities that do not obviously result from learning or experience. Today, various animals are said to possess a survival instinct, migratory instinct, herding instinct, maternal instinct, or language instinct. But a closer look reveals that these and other 'instincts' are not satisfactorily described as inborn, pre-programmed, hardwired, or genetically determined. Rather, research in this area teaches us that species-typical behaviors develop-and they do so in every individual under the guidance of species-typical experiences occurring within reliable ecological contexts. WIREs Cogn Sci 2017, 8:e1371. doi: 10.1002/wcs.1371 For further resources related to this article, please visit the WIREs website.

The Developmental Systems Approach and the Analysis of Behavior

The developmental systems approach is a perspective that has been adopted by increasing numbers of developmental scientists since it emerged in the twentieth century. The overview presented in this paper makes clear that proponents of this approach and proponents of modern behavior analysis should be natural allies. Despite some distinctions between the two schools of thought, the essential ideas associated with each are compatible with the other; in particular, scientists in both camps work to analyze the provenance of behavior and recognize the central role that contextual factors play in behavioral expression.

Infant Social Development across the Transition from Crawling to Walking

The onset of walking is a developmental transition that sets in motion a cascade of change across a range of domains, including social interactions and language learning. However, research on the unfolding of such change in the infant across this transition is limited. This investigation utilized a longitudinal design to examine the effect of walking acquisition on infant social development and parent perceptions of the infant to explore how changes in these factors relate with infant language development. Parents reported on infant social behaviors and their perception of the infant, as well as motor and language development, in 2-week intervals from 10.5 to 13 months of age. Mixed linear models revealed infant initiation of joint engagement (e.g., pointing, bringing objects to the parent) and following of the parent's joint engagement cues (e.g., point following, gaze following) increased as a function of infant walking experience, particularly between 2- and 4-weeks after the onset of walking, independent of age. Additionally, the parent's perception of the infant as an individual increased between 2- and 4-weeks after the infant began to walk. Finally, the unique relations of infant walking experience, following of social cues, and the parents' perception of the infant as an individual with infant language development were examined. Infant following of joint engagement behaviors and parent perception of the infant as an individual were related to receptive, but not productive, vocabulary size. Additionally, infant walking experience remained a significant predictor of infant receptive and productive language. These findings provide insight on important factors that change as the infant begins to walk. Future research utilizing more direct assessment of these factors is described, as well as general patterning of developmental change across the transition from crawling to walking.

Language at Three Timescales: The Role of Real-Time Processes in Language Development and Evolution

Evolutionary developmental systems (evo-devo) theory stresses that selection pressures operate on entire developmental systems rather than just genes. This study extends this approach to language evolution, arguing that selection pressure may operate on two quasi-independent timescales. First, children clearly must acquire language successfully (as acknowledged in traditional evo-devo accounts) and evolution must equip them with the tools to do so. Second, while this is developing, they must also communicate with others in the moment using partially developed knowledge. These pressures may require different solutions, and their combination may underlie the evolution of complex mechanisms for language development and processing. I present two case studies to illustrate how the demands of both real-time communication and language acquisition may be subtly different (and interact). The first case study examines infant-directed speech (IDS). A recent view is that IDS underwent cultural to statistical learning mechanisms that infants use to acquire the speech categories of their language. However, recent data suggest is it may not have evolved to enhance development, but rather to serve a more real-time communicative function. The second case study examines the argument for seemingly specialized mechanisms for learning word meanings (e.g., fast-mapping). Both behavioral and computational work suggest that learning may be much slower and served by general-purpose mechanisms like associative learning. Fast-mapping, then, may be a real-time process meant to serve immediate communication, not learning, by augmenting incomplete vocabulary knowledge with constraints from the current context. Together, these studies suggest that evolutionary accounts consider selection pressure arising from both real-time communicative demands and from the need for accurate language development.

The Study of Process and the Nature of Explanation in Developmental Science

The question of “how” occupies center stage in the explanatory efforts of developmental science and establishes the study of process as the field's defining mission. In line with this mission, recent decades have witnessed a new wave of focus on taking seriously issues of time, variability, and context in the study of development. For many in the field, however, fully espousing a process orientation for developmental science requires an abandonment of the structural explanation in which the field is historically steeped—for example, the organizational sequencing and directionality established in the “grand theories” of classic developmental accounts. Metatheoretically, the idea that a process orientation actively conflicts with a structural orientation rests on the conceptual conflation of different kinds of structural explanation. Such conceptual conflation, in turn, derives from the adoption of an ontological framework that reduces all explanation to mechanistic antecedent–consequent relations. The purpose of this article is to frame developmental science's pursuit of the question of “how” within the broader context of metatheoretical division that characterizes the field's approach to explanation itself.

Novel methodology to examine cognitive and experiential factors in language development: combining eye-tracking and LENA technology

Developmental systems theory posits that development cannot be segmented by influences acting in isolation, but should be studied through a scientific lens that highlights the complex interactions between these forces over time (Overton, 2013a). This poses a unique challenge for developmental psychologists studying complex processes like language development. In this paper, we advocate for the combining of highly sophisticated data collection technologies in an effort to move toward a more systemic approach to studying language development. We investigate the efficiency and appropriateness of combining eye-tracking technology and the LENA (Language Environment Analysis) system, an automated language analysis tool, in an effort to explore the relation between language processing in early development, and external dynamic influences like parent and educator language input in the home and school environments. Eye-tracking allows us to study language processing via eye movement analysis; these eye movements have been linked to both conscious and unconscious cognitive processing, and thus provide one means of evaluating cognitive processes underlying language development that does not require the use of subjective parent reports or checklists. The LENA system, on the other hand, provides automated language output that describes a child's language-rich environment. In combination, these technologies provide critical information not only about a child's language processing abilities but also about the complexity of the child's language environment. Thus, when used in conjunction these technologies allow researchers to explore the nature of interacting systems involved in language development.

The Developing Social Context of Infant Helping in Two U.S. Samples

Theories about the development of helping make different assumptions about infants' everyday experiences. Yet little research has investigated early helping at home. Two studies investigated the presence, encouragement, and social reinforcement of helping in 11- to 25-month-old infants in U.S. middle-class families. In Study 1, 76 mothers provided descriptions of infant helping. Study 2 involved videotaping of naturalistic interactions in 51 families. From around the first birthday, most infants helped at home. Instances of helping were frequently accompanied by encouragement, thanking, or praising. Longitudinal and cross-sectional findings were consistent with the view that family members' involvement contributes to infant helping, although the role of family members may depend on infant age. These findings have implications for theories and research about infant helping.

Is cognition enough to explain cognitive development?

Traditional views separate cognitive processes from sensory-motor processes, seeing cognition as amodal, propositional, and compositional, and thus fundamentally different from the processes that underlie perceiving and acting. These were the ideas on which cognitive science was founded 30 years ago. However, advancing discoveries in neuroscience, cognitive neuroscience, and psychology suggests that cognition may be inseparable from processes of perceiving and acting. From this perspective, this study considers the future of cognitive science with respect to the study of cognitive development.

Early gait development in human infants: Plasticity and clinical applications

In this paper we focus on how a developmental perspective on plasticity in the control of human movement can promote early therapy and improve gait acquisition in infants with developmental disabilities. Current knowledge about stepping development in healthy infants across the first year of life highlights strong plasticity, both in behavioral outcome and in underlying neuro-muscular activation. These data show that stepping, like other motor skills, emerges from the interaction between infant's maturation and the environment. This view is reinforced by showing that infants with different internal resources (like genetic disorder or neural tube defect) show unique developmental trajectories when supported on a treadmill, yet do respond. Moreover, we will show that their behavior can be improved by context manipulations (mostly sensory stimulation) or practice. Overall, plasticity in the neural, skeletal, and muscle tissues create new opportunities for optimizing early intervention by creatively tapping into the same developmental processes experienced by healthy infants.

Definitions and Developmental Processes in Research on Infant Morality

Key terms in research on moral development also exist in everyday language. Tafreshi and her colleagues (2014) propose that researchers should use terms in ways consistent with their usage by non-researchers. This commentary questions this claim, and argues for the importance of providing clear and explicit definitions of terms such as "morality" and "innate," of showing caution when attributing evaluations and judgments to infants, and of considering developmental processes preceding and succeeding the abilities demonstrated using looking-time and related measures. Progress is unlikely to result from conceptual analysis alone. However, conceptual clarity will make it easier to see what theories agree and disagree about as well as how opposing claims can be tested empirically.

Staring us in the face? An embodied theory of innate face preference

Human expertise in face perception grows over development, but even within minutes of birth, infants exhibit an extraordinary sensitivity to face-like stimuli. The dominant theory accounts for innate face detection by proposing that the neonate brain contains an innate face detection device, dubbed 'Conspec'. Newborn face preference has been promoted as some of the strongest evidence for innate knowledge, and forms a canonical stage for the modern form of the nature-nurture debate in psychology. Interpretation of newborn face preference results has concentrated on monocular stimulus properties, with little mention or focused investigation of potential binocular involvement. However, the question of whether and how newborns integrate the binocular visual streams bears directly on the generation of observable visual preferences. In this theoretical paper, we employ a synthetic approach utilizing robotic and computational models to draw together the threads of binocular integration and face preference in newborns, and demonstrate cases where the former may explain the latter. We suggest that a system-level view considering the binocular embodiment of newborn vision may offer a mutually satisfying resolution to some long-running arguments in the polarizing debate surrounding the existence and causal structure of newborns' 'innate knowledge' of faces.

Maternal behaviors promoting language acquisition in slow-to-talk toddlers: prospective community-based study

OBJECTIVE

To determine, in a community-based sample of slow-to-talk toddlers, the extent to which specific maternal responsive behaviors at 24 months predict child language at 24 and 36 months.

METHODS

Mother-child dyads were recruited for this prospective longitudinal study from 3 local government areas spanning low, middle, and high socioeconomic status in Melbourne, Australia. At child age 18 months, 1138 parents completed a 100-word expressive vocabulary checklist; the 251 (22.1%) children scoring ≤20th percentile were then followed up to comprise this study.

PREDICTORS

Six maternal responsive behaviors (imitations, interpretations, labels, expansions, supportive directives and responsive questions) were derived from mother-child free-play videos collected at 24 months of age and coded using the Observer XT system.

OUTCOMES

Expressive and receptive language measured at 24 and 36 months of age (Preschool Language Scale-4), blind to maternal responsiveness ratings.

RESULTS

Two hundred and twenty-six of the 251 (90.0%) mother-child dyads were followed up at 36 months. In confounder-adjusted linear regression analyses, expansions, imitations, and responsive questions were strongly associated with better receptive and expressive language at 24 and 36 months. Labels unexpectedly predicted poorer expressive language at 36 months. Expansions were the only maternal behavior that predicted improvement in language between 24 and 36 months.

CONCLUSIONS

Maternal responsive behaviors, particularly expansions, offer promise in enhancing early language learning in slow-to-talk toddlers. Parent-child interactions characterized by frequent use of maternal labels at 24 months could also be a predictive marker of those slow-to-talk toddlers at greater risk of persistent language problems.

An introduction to evolutionary developmental psychology

Evolutionary developmental psychology represents a synthesis of modern evolutionary theory and developmental psychology. Here we introduce the special issue on evolutionary developmental psychology by briefly discussing the history of this field and then summarizing the variety of topics that are covered. In this special issue, leading researchers provide a collection of theoretical and empirical articles that highlight recent findings and propose promising areas for future research.

An Introduction to Evolutionary Developmental Psychology

Evolutionary developmental psychology represents a synthesis of modern evolutionary theory and developmental psychology. Here we introduce the special issue on evolutionary developmental psychology by briefly discussing the history of this field and then summarizing the variety of topics that are covered. In this special issue, leading researchers provide a collection of theoretical and empirical articles that highlight recent findings and propose promising areas for future research.

The role of stimulus novelty on children's inflexible dimensional switching

Children's ability to flexibly shift attention between different representational schemes was investigated using the dimensional change card sorting task. Across three experiments (N = 56 three-year-olds and N = 40 four-year-olds in ; N = 14 three-year-olds in ; and N = 14 three-year-olds in ) the role of perceptual information on children's cognitive flexibility was investigated by manipulating different aspects of the task materials between pre- and postswitch phases. Better performance was observed when either task-relevant (the color or shape of the images on the cards) or task-irrelevant information (the background color or shape of the actual cards) was changed, with this improvement occurring when the changes were salient enough to induce a stimulus novelty effect.