The nature of intelligence remains scientifically poorly understood and the subject of many disagreements both biologically and psychologically. Its true form, the nature of its variation and its evolutionary origins remain unclear. The main problem, it is suggested here, is an inadequate grasp of what intelligence is for – due, in turn, to an over-simple, idealized, view of the environmental challenges intelligence evolved to meet. Here, a description of real environmental complexity is advanced, confounding the dominant view of intelligence as a passive, adaptationist, product of evolutionary forces. Through active development, intelligence became the very basis of the origins of life, and then a foundation principle in the evolution of living things, and their complex functions. This unifying perspective is illustrated, from origins of life, through single cell metabolism to human culture.

We discuss the four chapters in this special issue, focusing on three key questions: (1) what developmental theories are being used across chapters; (2) what neuroscience methods are being used; and (3) how are these integrated? We organize our discussion by chapter moving from the broadest conceptual chapter by Peter Marshall through to the integration of theory and methods by Crone and van Drunen. We end by discussing work that is missing from the special issue that uses neural process models to integrate developmental theory with cognitive neuroscience methods. We highlight how this approach can yield a tighter integration between theory and methods, enabling researchers to test specific hypotheses about the mechanisms that underlie change in development. We suggest that this approach might prove to be a particularly effective way to keep theory at the forefront of developmental neuroscience.

Racism is an element of the sociocultural context that may significantly impact personal identity development among youth of color in the USA. However, theories of personal identity development largely do not consider the influence of racialized experiences. This paper presents a theoretical framework of the role of racism on adolescent personal identity development (RAPID framework); we demonstrate its utility with the example of interpersonal forms of racism in the context of racially marginalized youth in the USA. The RAPID framework combines psychological and sociological perspectives on identity development to describe moments in the process that may be affected by aspects of racism (e.g., stereotypes, biases). Empirical support for aspects of the framework is drawn from research on adolescents’ ethnic-racial identities and specific aspects of personal identities (e.g., academic identity). To create environments that promote positive personal identity development for ethnic-racially marginalized youth, the RAPID framework addresses potential barriers that can be eliminated and highlights aspects of resilience that can be supported. Suggestions for empirical research on the RAPID framework, as well as for theoretical extensions of it, are discussed.

Primal world beliefs (“primals”) capture individuals’ basic understanding of what sort of world this is. How do children develop beliefs about the nature of the world? Is the world a good place? Safe or dangerous? Enticing or dull? Primals were initially introduced in social and personality psychology to understand beliefs about the world as a whole that may influence well-being and personality. This article introduces the concept of primals to developmental scientists and reviews preliminary research examining how primals relate to sociodemographic and well-being indicators. The article then situates the concept of primals in some classic developmental theories to illustrate testable hypotheses these theories suggest regarding how primals develop. Understanding how individuals develop basic beliefs about the nature of the world deepens insights into the human experience, including how malleable these beliefs might be and how they may be influenced by, and in turn influence, other domains of development.

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, and 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 in advance 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.

Can the study of epigenetics, physiology, and cognitive science contribute to the investigation and understanding of social-cultural systems while respecting the autonomy of social research? I present a developmental system theory (DST) approach, which takes the unit of analysis to be the system of self-sustaining interactions among multiple biological, psychological, and social resources. On this view, the cybernetic architecture of the networks that constitute the system channels development so that different trajectories lead to convergent end states, accounting for the system’s developmental stability as well as shedding light on the conditions that lead to departures from typical outcomes. Based on previous work, which is extended here, I suggest that Waddington’s epigenetic landscape metaphor, which was built to illustrate the relationship between genetic networks and embryological development, is a useful tool for thinking about the temporal dynamics of social systems, capturing some important features of social stability and change at different scales and levels of social organization. I discuss five social systems using the landscape metaphor and explore the implications of this DST approach for investigating the relations between sociocultural development and evolution.

Our systematic qualitative analysis advances the field of human development with an integrative review of sensory research in children’s reading of books and e-books. Based on a systematic literature review of 35 papers, we qualitatively synthesise multidisciplinary literature concerned with children’s sensory development and the activity of reading. We map the studies’ characteristics, including their methodological designs and primary theoretical concepts (embodiment and materiality). We highlight empirical research gaps and lack of literature attention particularly for critical engagement with sensorial research. We find notable terminological discrepancies across qualitative and quantitative studies and insufficient emphasis on the developmental aspects of children’s sensory reading and its dynamic interaction with books’ affordances. Our theoretical contribution lies in identifying the emerging area of multisensory m(ai)cro research as a future agenda for studies of children’s reading, which we support with a terminological guide and a conceptual framework.