Building Bridges: Cognitive Development in Typical and Atypical Populations

Abstract

Most research reported in the Journal of Cognition and Development focuses on typically developing children—those who are following what is assumed to be the most common path. This special issue was designed to foster a dialogue between cognitive developmentalists who work on typical development and those who work on atypical development, with the goal of illustrating how recent findings can advance thinking in both fields. The 6 target articles and 2 commentaries in this special issue provide a compelling demonstration of the symbiotic nature of the study of typical and atypical cognitive development.

The Journal of Cognition and Development (JCD) is the official journal of the Cognitive Development Society (CDS), a professional organization that includes basic and applied scientists, as well as practitioners. According to the organization’s Website, members share an interest in “change and continuity in the intellectual processes that support mental life.” Most members of CDS (and readers of JCD) study typical development—the development of individuals who are following what is considered to be the most common path. Most of us conduct research with samples of children who hear, see, attend, learn, talk, and reason in ways that we assume allow generalizations about most or all typically developing (TD) children (though we know it is almost certainly not true; Henrich, Heine, & Norenzayan, 2010). Indeed, of the titles of the 48 articles published in 2015 in JCD, only 1 referenced atypical development (Goldin-Meadow, Namboodiripad, Mylander, Ozyurek, & Sancar, 2015).

Why, then, is JCD devoting an entire special issue—the first to appear in the journal—to cognitive development in atypical populations? We highlight three reasons. First, a field that focuses almost exclusively on TD children does not capture the “intellectual processes that support mental life” for a significant number of people. Among children aged 5 to 17 years old in the United States, for example, at least 5% have a visual, hearing, cognitive, language, ambulatory, and/or self-care difficulty (Brault, 2011). In most published studies in cognitive development, atypically developing children are not recruited or included, presumably because we expect they may think differently from TD children, which complicates the inferences we would like to make about cognition and/or development. And yet, paraphrasing Dunham and Olson in this issue, we assume it is uncontroversial that our science and theories should capture the wide variation in the intellectual processes supporting the mental life of all children. Using examples from research programs involving multiracial, intersex, and transgender children, Dunham and Olson argue persuasively that developmental science will be strengthened by including a full range of children, both as participants and (in the case of research on social cognition) as targets of social perception.

A second reason for this issue’s focus on atypical development is that even though most cognitive developmentalists do not conduct research with atypical populations, we routinely suggest in articles and grant proposals that our work is relevant to these groups. For example, we regularly claim that understanding the typical development of X is crucial to understanding how and why it goes awry in Disorder Y. Developmental psychopathologists have long described the value of this approach (e.g., Cicchetti, 1984; Werner, 1957; Zigler, 1967). But in practice, most of us who study TD children characterize a phenomenon with a particular TD sample and move on, leaving others to figure out how or whether the work is actually relevant to atypical development. This practice is understandable: No one can be an expert in everything. But it means that a valuable opportunity to create a meaningful bridge to atypical development may be lost.

When cognitive developmentalists do conduct studies with atypically developing samples, the most common approach is to compare their performance to that of a group of TD individuals. On the surface, this approach seems like it could be informative, but there are at least two potential pitfalls. First, the focus of these comparative studies tends to be on differences. When similarities are uncovered, they are often considered uninteresting or are dismissed as reflecting a lack of power or sensitivity in the measure. But similarities can be at least as informative as differences. For example, in this issue, Ferrara, Hoffman, O’Hearn, and Landau found that individuals with Williams syndrome (WS) cannot track as many moving targets on a visuospatial task as those without WS. However, they also found that the performance of both groups was subject to the same signature constraint in spatiotemporal continuity. This finding suggests that the mechanism responsible for multiple object tracking—which, as Ferrara et al. point out, is an essential skill for everything from reaching to driving—is highly constrained across different types of people and different levels of visuospatial processing.

Another potential pitfall to the classic comparative approach is that when group differences are uncovered, they are often reified and attributed to some kind of stable “deficit” in the minority group (Akhtar & Jaswal, 2013; Akhtar, Jaswal, Dinishak, & Stephan, in press; Medin, Bennis, & Chandler, 2010). For example, in Baron-Cohen, Leslie, and Frith’s (1985) classic article, “Does the Autistic Child Have a ‘Theory of Mind’?” most 4.5-year-old nonautistic children passed the Sally-Anne false-belief task, whereas most 12-year-old autistic children did not. Demonstrations like this one, in which participants with autism performed poorly compared with nonautistic participants when reasoning about the social world, contributed to claims like: “We propose that what all people with autism have in common is a particular cognitive deficit that gives rise to the core symptoms in the course of development … [they lack] the ability to predict and explain the behavior of other humans in terms of their mental states” (Frith, Morton, & Leslie, 1991, p. 434).

But a “deficit” (like any behavior) can only be understood in the context in which it was studied. Like anyone else, autistic children’s ability to reason about others’ mental states will depend on a number of factors, including their understanding of what is being asked of them, their motivation to respond to the question, their reaction to the particular stimuli, their history in testing situations, their relationship to the questioner, and so on. For example, Peterson, Slaughter, Peterson, and Premack (2013) found that when the Sally-Anne false-belief task was framed in a competitive manner, most 10-year-old autistic children in their sample passed.

The importance of characterizing and understanding behavior in context is a foundational principle of developmental psychopathology (e.g., Burack, 1997; Sroufe & Rutter, 1984). In our view, it leads to research and conclusions that are much more complicated, much more interesting, and much more likely to provide an accurate picture of the individuals and phenomena under study. For example, in this issue, Burack and colleagues review a body of work demonstrating that attentional abilities in autism can vary in dramatic ways depending on how they are assessed. They argue for shifting the scientific discourse from whether or how well autistic people attend to how they attend, including how they deploy their attentional resources in the course of their daily lives. For cognitive developmentalists who work on typical development but who would like to conduct (or collaborate on) research with atypically developing populations, we hope the articles in this issue serve as useful examples of research programs that go beyond the familiar but flawed and generally unhelpful paradigm that frames differences as deficits.

The third reason for this special issue’s focus on cognitive development in atypical populations is that just as the study of typical development can inform our understanding of atypical development, so too can the study of atypical development inform our understanding of typical development (e.g., Cicchetti, 1984; Cicchetti & Cohen, 2006; Hodapp & Burack, 1990). This statement is evident from a number of contributions to this issue. For example, Landry and Chouinard explain that some individuals show personality and cognitive traits that are similar to (but milder than) those with a diagnosis of autism. Most research on this so-called broader autism phenotype (BAP) has focused on what it can reveal about the nature of autism, but Landry and Chouinard point out that the BAP could also be used to study individual differences in typical development in domains like social cognition and communication.

Another example of how the study of atypical development can inform the study of typical development comes from Demir-Lira and Levine’s contribution to this issue. They uncovered different trajectories in the growth (and loss) of reading abilities during the academic year and summer in children who had experienced prenatal or perinatal brain lesions and TD children from a variety of socioeconomic backgrounds. Their findings are important both for developing tailored interventions and for understanding the underlying biological and environmental factors likely to be relevant to reading development in all children. Similarly, in their article, Paterson, Parish-Morris, Hirsh-Pasek, and Golinkoff highlight the ways that longitudinal studies of neurodevelopmental disorders, such as autism, can inform the ways in which we understand the structure, complexity, and nuances of developmental trajectories in all children.

Our call for proposals for this special issue yielded more than 80 abstracts, on topics ranging from autism to deafness to preterm infants, from Tourette syndrome to attention-deficit hyperactivity disorder to intellectual disability. We wish we had been able to accommodate more articles in this special issue but hope that the six that follow (along with the commentaries by Michael Chandler and by Susan Graham and Sheri Madigan) inspire and motivate you, as they did us, to consider ways to meaningfully bridge cognitive development in typical and atypical populations.