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AbstractIn this article, the authors take a very conservative view of the contribution of animal models to an understanding of human development. We do not think that homologies can be readily documented with even our most closely related relatives' behavior and psychological functioning. The major contribution of animal models is their provision of food for thought (hypotheses, not facts) about human development and general principles of development, and we describe some of the more significant and interesting of these at length. We also briefly discuss the other applications of animal research toward understanding the development and evolution of behavior, more generally speaking.

Currently, a central problem for theoretical biology is the integration of development with genetics and evolutionary theory. Through the late 20th century, biologists held that animals resemble their ancestors strictly because of the transgenerational transmission of DNA. This view effectively wrote development out of evolutionary biology. However, many molecular and developmental biologists now understand that phenotypes – anatomical, physiological, and behavioral traits – are not determined by genes (i.e., DNA segments) alone; instead, they emerge epigenetically from developmental processes involving co-acting genetic factors, environmental factors, molecular epigenetic factors, <i>and</i> other non-genetic factors within organisms' bodies. This insight forces a rethinking of biological inheritance. Perspectives focusing on the dynamics of developmental systems offer a compelling alternative way to think about inheritance, providing a powerful substitute to the reductionistic framework that attributes phenotypic outcomes to genetic instructions set <i>in advance</i> of developmental processes. Rethinking genetics, epigenetics, and inheritance by focusing on the dynamics of developmental systems helps highlight the bidirectional effects of evolutionary and developmental processes on one another, yielding a more integrated understanding of development, inheritance, and evolution. Simultaneously, this approach encourages rejection of genetic determinism, a simplistic perspective that continues to appear in psychological writing, despite its biological implausibility.

Conceptual and empirical advances across the biological and psychological sciences have made it increasingly clear that genetic and environmental factors cannot be meaningfully partitioned when attempting to explain development. This should be a major theme within the contemporary field of epigenetics. However, the field has yet to fully extricate itself from reductionist tendencies in its conceptualization of developmental relations. Epigenetics today still routinely promotes both a reductionist privileging of molecular over molar levels of explanation and a reductionist focus on separate and distinct roles for genes and environment in any given developmental relation. We argue that the field needs to more rigorously pursue a process-oriented framework that is integrated across molecular, organismal, and environmental levels of biological organization. Transcending the worn and outdated nature-nurture controversy will require a truly <i>developmental epigenetics</i> that embraces the importance of emergence, context, and hierarchical relations in all developmental explanation.

New attempts in psychological science at integrating developmental (individual-level) and evolutionary (population-level) accounts of phenotypic stability and variability have achieved increasing prominence of late. Foremost among such attempts is the field of evolutionary developmental psychology (EDP). EDP proposes that selective pressures in evolution inform psychological development through a synthesis of the Darwinian/neo-Darwinian selectionist perspective embraced by evolutionary psychology and the developmental dynamics perspective endorsed by developmental systems theory. We examine the theoretical assumptions behind selectionist and developmental perspectives and argue that both perspectives are ontologically incompatible. We provide an alternative framework for integrating developmental and evolutionary explanations that transcend this ontological division of selectional and developmental perspectives. This framework promotes a pluralistic approach that moves beyond traditional antecedent/consequent, mechanistic views of causality and embraces both functional (part-to-whole) <i>and</i> structural (whole-to-part) modes of explanation as distinct, equally legitimate, and simultaneously applicable perspectives in understanding phenotypic stability and variability over time.

Proponents of the Extended Evolutionary Synthesis (EES) emphasize the critical role that organisms and their development play in the process of evolution. This framework explicitly rejects the genocentric focus that once dominated interpretations of the Modern Synthesis in evolutionary theory. In place of genocentrism, EES highlights processes like niche construction, developmental constraint, and extragenetic inheritance as central to any understanding of the evolutionary process. However, much more is at stake in adopting the EES than simply moving beyond the gene-dominant viewpoint of the Modern Synthesis. The EES, in fact, represents a fundamental challenge to the core of classic Darwinism itself by actively repudiating Darwin's key idea that natural selection acts as a creative force in the construction of phenotypes and phenotypic change. In this paper, we more fully explore the assumptive base of Darwinism's population-oriented, selectional focus. We demonstrate how taking development seriously in evolutionary theory mandates a systematic overhaul of Darwinism's assumptive base in favor of grounding all understanding of phenotypic construction in the developmental processes of self-organization endemic to organisms' active engagement with their worlds.

AbstractWe assessed whether exposure to amodal properties in bimodal stimulation (e.g. rhythm, rate, duration) could educate attention to amodal properties in subsequent unimodal stimulation during prenatal development. Bobwhite quail embryos were exposed to an individual bobwhite maternal call under several experimental and control conditions during the day prior to hatching. Experimental groups received redundant auditory and visual exposure to the temporal features of an individual maternal call followed by unimodal auditory exposure to the same call immediately or after a 2‐hr or 4‐hr delay. Control groups received (1) the same exposure but in the reverse sequence (unimodal → redundant bimodal), (2) asynchronous bimodal → unimodal, (3) only unimodal exposure, or (4) only bimodal exposure. All experimental groups showed a significant preference for the familiar maternal call over a novel maternal call when tested 2 days after hatching, whereas none of the control groups showed a significant preference for the familiar call. These results indicate that intersensory redundancy can direct attention to amodal properties in bimodal stimulation and educate attention to the same amodal properties in subsequent unimodal stimulation where no intersensory redundancy is available.

AbstractPrior research has demonstrated intersensory facilitation for perception of amodal properties of events such as tempo and rhythm in early development, supporting predictions of the Intersensory Redundancy Hypothesis (IRH). Specifically, infants discriminate amodal properties in bimodal, redundant stimulation but not in unimodal, nonredundant stimulation in early development, whereas later in development infants can detect amodal properties in both redundant and nonredundant stimulation. The present study tested a new prediction of the IRH: that effects of intersensory redundancy on attention and perceptual processing are most apparent in tasks of high difficulty relative to the skills of the perceiver. We assessed whether by increasing task difficulty, older infants would revert to patterns of intersensory facilitation shown by younger infants. Results confirmed our prediction and demonstrated that in difficult tempo discrimination tasks, 5‐month‐olds perform like 3‐month‐olds, showing intersensory facilitation for tempo discrimination. In contrast, in tasks of low and moderate difficulty, 5‐month‐olds discriminate tempo changes in both redundant audiovisual and nonredundant unimodal visual stimulation. These findings indicate that intersensory facilitation is most apparent for tasks of relatively high difficulty and may therefore persist across the lifespan.

The practice of science entails more than just repeated cycles of theory construction, hypothesis generation, and empirical investigation. Broader, metatheoretical levels of conceptualization necessarily condition all aspects of the research process, establishing the very meaning and sensibility of science's empirical and theoretical activities. When debate arises at these metatheoretical levels, it is the subject of conceptual analysis, not empirical investigation. In this article, we examine the overarching metatheoretical divide that lies at the heart of many key theoretical debates in science: the divide between a Cartesian-Split-Mechanistic research paradigm and a Process-Relational research paradigm. We instantiate this divide in terms of three prominent domains of inquiry within developmental science: the study of epigenesis (including epigenetics); the study of embodiment, specifically embodied cognition; and the study of baselines for human nature and development. We reveal how core issues and theoretical debates within these domains derive from metatheoretical, not theoretical, points of contention.