Online research in philosophy

Developmental systems theory is an attempt to sum up the ideas of a research tradition in developmental psychobiology that goes back at least to Daniel Lehrman’s work in the 1950s. It yields a representation of evolution that is quite capable of accommodating the traditional themes of natural selection and also the new results that are emerging from evolutionary developmental biology. But it adds something else - a framework for thinking about development and evolution without the distorting dichotomization of biological processes into gene and non-gene and the vestiges of the ‘black-boxing’ of developmental processes in the modern synthesis, such as the asymmetric use of the concept of information. Phenomena that are marginalized in current gene-centric conceptions, such as extra-genetic inheritance, niche construction and phenotypic plasticity are placed center stage.

Recent theories in cognitive science have begun to focus on the active role of organisms in shaping their own environment, and the role of these environmental resources for cognition. Approaches such as situated, embedded, ecological, distributed and particularly extended cognition look beyond ‘what is inside your head’ to the old Gibsonian question of ‘what your head is inside of’ and with which it forms a wider whole—its internal and external cognitive niche. Since these views have been treated as a radical departure from the received view of cognition, their proponents have looked for support to similar extended views within (the philosophy of) biology, most notably the theory of niche construction. This paper argues that there is an even closer and more fruitful parallel with developmental systems theory and developmental niche construction. These ask not ‘what is inside the genes you inherited’, but ‘what the inherited genes are inside of’ and with which they form a wider whole—their internal and external ontogenetic niche, understood as the set of epigenetic, social, ecological, epistemic and symbolic legacies inherited by the organism as necessary developmental resources. To the cognizing agent, the epistemic niche presents itself not just as a partially self-engineered selective niche, as the niche construction paradigm will have it, but even more so as a partially self-engineered ontogenetic niche, a problem-solving resource and scaffold for individual development and learning. This move should be beneficial for coming to grips with our own (including cognitive) nature: what is most distinctive about humans is their developmentally plastic brains immersed into a well-engineered, cumulatively constructed cognitive–developmental niche.

Nancy Tuana holds that the nature/nurture dichotomy does not accurately represent the world and hence that a whole series of assumptions about human nature is mistaken. She rejects both biological determinism and alternative interactionist views. I argue that although her arguments and political concerns do rule out any kind of simple biological determinism, they do not show that the alternative interactionist view is untenable: in fact, she uses the distinction in her attempt to demolish it. I argue that the assumption that "nature" implies fixity is the source of difficulties here, not the dichotomy itself.

We are each the product of our development. The nature of the developmental process by which each of us was formed is described from gametogenesis to neonatality. The varied influences upon that process and their relative balance and patterns of interaction are then considered. In particular, the relative importance of epigenetic and genetic factors is discussed. It is concluded that development is a continuous process involving epigenetic/genetic interactions throughout. The contemporary emphasis on the genetic basis for human individuality is reviewed critically.

Despite great advances in understanding genetic mechanisms, there still exists a bias toward equating genes with innate modules that determine important developmental events. But genes are equally relevant to understanding developmental plasticity shaped by ecological events. In other words, the term 'genetic inheritance' does not specify ontogenetic mechanisms. Here we present a case history of a species assumed to be under the control of prespecified genetic wiring to direct critical behavioral events such as communication and mating. We show, however, that exogenetic processes stemming from the species's ontogenetic niche provide an alternative view of the flexibility of development especially with respect to behavioral performance.

Developmental systems theory (DST) is a general theoretical perspective on development, heredity and evolution. It is intended to facilitate the study of interactions between the many factors that influence development without reviving `dichotomous' debates over nature or nurture, gene or environment, biology or culture. Several recent papers have addressed the relationship between DST and the thriving new discipline of evolutionary developmental biology (EDB). The contributions to this literature by evolutionary developmental biologists contain three important misunderstandings of DST.

In the last decade it has become en vogue for cognitive comparative psychologists to study animal behavior in an ‘integrated’ fashion to account for both the ‘innate’ and the ‘acquired’. We will argue that these studies, instead of really integrating the concepts of ‘nature’ and ‘nurture’, rather cement this old dichotomy. They combine empty nativist interpretation of behavior systems with blatantly environmentalist explanations of learning. We identify the main culprit as the failure to take development seriously. While in some areas of biology interest in the relationship between behavior and development has surged through topics such as extragenetic inheritance, niche construction, and phenotypic plasticity, this has gone almost completely unnoticed in the study of animal behavior in comparative psychology, and is frequently ignored in ethology too. The main aims of this paper are to clarify the relationship between the concepts of learning, experience, and development, and to investigate whether and how all three concepts can be usefully deployed in the study of animal behavior. This will require the full integration of the psychological study of behavior into biology, and of the idea of learning into a wider concept of experience. We lay out how, in a systems view of development, learning may just appear as one among many processes in which experience influences behavior. This new synthesis should help to overcome the age-old dualism between innate and acquired. It thereby opens up the possibility of developing scientifically more fruitful distinctions.

The dichotomy between Nature and Nurture, which has been dismantled within the framework of development, remains embodied in the notions of plasticity and evolvability. We argue that plasticity and evolvability, like development and heredity, are neither dichotomous nor distinct: the very same mechanisms may be involved in both, and the research perspective chosen depends to a large extent on the type of problem being explored and the kinds of questions being asked. Epigenetic inheritance leads to transgenerationally extended plasticity, and developmentally-induced heritable epigenetic variations provide additional foci for selection that can lead to evolutionary change. Moreover, hereditary innovations may result from developmentally induced large-scale genomic repatterning events, which are akin to Goldschmidtian “systemic mutations”. The epigenetic mechanisms involved in repatterning can be activated by both environmental and genomic stress, and lead to phylogenetic as well as ontogenetic changes. Hence, the effects and the mechanisms of plasticity directly contribute to evolvability.

The Modern Synthesis of Darwinism and genetics regards non-genetic factors as merely constraints on the genetic variations that result in the characteristics of organisms. Even though the environment (including social interactions and culture) is as necessary as genes in terms of selection and inheritance, it does not contain the information that controls the development of the traits. S. Oyama’s account of the Parity Thesis, however, states that one cannot conceivably distinguish in a meaningful way between nature-based (i.e., gene-based) and nurture-based (i.e., environment-based) characteristics in development because the information necessary for the resulting characteristics is contained at both levels. Oyama and others argue that the Parity Thesis has far-reaching implications for developmental psychology, in that both nativist and interactionist developmental accounts of motor, cognitive, affective, social, and linguistic capacities that presuppose a substantial nature/nurture dichotomy are inadequate. After considering these arguments, we conclude that either Oyama’s version of the Parity Thesis does not differ from the version advocated by liberal interactionists, or it renders precarious any analysis involving abilities present at birth (despite her claim to the contrary). More importantly, developmental psychologists need not discard the distinction between innate characteristics present at birth and those acquired by learning, even if they abandon genocentrism. Furthermore, we suggest a way nativists can disentangle the concept of maturation from a genocentric view of biological nature. More specifically, we suggest they can invoke the maturational segment of the developmental process (which involves genetic, epigenetic and environmental causes) that results in the biological “machinery” (e.g. language acquisition device) which is necessary for learning as a subsequent segment of the developmental process.

S. Oyama’s prominent account of the Parity Thesis states that one cannot distinguish in a meaningful way between nature-based (i.e. gene-based) and nurture-based (i.e. environment-based) characteristics in development because the information necessary for the resulting characteristics is contained at both levels. Oyama as well as P. E. Griffiths and K. Stotz argue that the Parity Thesis has far-reaching implications for developmental psychology in that both nativist and interactionist developmental accounts of psychological capacities that presuppose a substantial nature/nurture dichotomy are inadequate. We argue that well-motivated abandoning of the nature/nurture dichotomy, as advocated in converging versions of the Parity Thesis in biology, does not necessarily entail abandoning the distinction between biologically given abilities necessary for the development of higher psychological capacities and the learning process they enable. Thus, contrary to the claims of the aforementioned authors, developmental psychologists need not discard a substantial distinction between innate (biologically given) characteristics and those acquired by learning, even if they accept the Parity Thesis. We suggest a two-stage account of development: the first stage is maturational and involves interaction of genetic, epigenetic and environmental causes, resulting in the endogenous biological ‘machinery’ (e.g. language acquisition device), responsible for learning in the subsequent stage of the developmental process by determining the organism’s responses to the environment. This account retains the crux of nativism (the endogenous biological structure determines the way the organism learns/responds to an environment) whilst adopting the developmentalist view of biology by characterizing environments as distinctly different in terms of structure and function in two developmental stages.