Better together: Novel methods for measuring and modeling development of executive function diversity while accounting for unity

Abstract

Executive functions (EFs) are linked to positive outcomes across the lifespan. Yet, methodological challenges have prevented precise understanding of the developmental trajectory of their organization. We introduce novel methods to address challenges for both measuring and modeling EFs using an accelerated longitudinal design with a large, diverse sample of students in middle childhood (N = 1,286; ages 8 to 14). We deployed adaptive assessments to equate EF challenge across ages and a data-driven, network analytic approach to reveal the evolving diversity of EFs while simultaneously accounting for their unity. This methodological paradigm shift brings new precision and clarity to EF development, showing number of components stabilizes by age 10, but refinement of component composition continues through at least age 14.

Testing the whole number interference hypothesis: Contributions of inhibitory control and whole number knowledge to fraction understanding.

“…A total of 1,280 third-through eighth-grade children participated in the Project iLead study, which was a longitudinal study over two school years (2016-2017 and 2017-2018) that investigated EF development in elementary and middle school (Younger et al, 2021(Younger et al, , 2022. Participants were recruited from nine schools in northern California-seven public schools in one district (five elementary K-5; two middle 6-8), one parochial K-8 school, and one private K-8 school.…”

“…The interplay between EFs and whole number knowledge may cause the interference effects on fraction comparison to grow as well. To investigate these relations, we analyzed cross-sectional data from third, fifth, and seventh graders that were collected as part of a larger, longitudinal study (Younger et al, 2021(Younger et al, , 2022. This cross-sectional sample affords a view across the first 5 years of fraction instruction in the United States and allows us to investigate how EFs and whole number knowledge relate to fraction comparison at three different stages in the development of these skills.…”

“…This study's design and its analysis were not preregistered. The data analyzed in this study represent a subset of the data collected, and data from the other measures will be reported elsewhere (Younger et al, 2021(Younger et al, , 2022. We report all data exclusions and all manipulations for the tasks of interest.…”

“…In the United States, fractions are typically introduced in third grade, and students should have developed considerable proficiency by the end of middle school in eighth grade (Common Core State Standards Initiative, 2010). Although several studies have considered the development of fraction knowledge over this time period (Kainulainen et al, 2017; Van Hoof et al, 2018), none to our knowledge have considered the changing role of cognitive building blocks like EFs or whole number knowledge, which continue to develop and improve over this age range (Constantinidis & Luna, 2019; Opfer & Siegler, 2007; Younger et al, 2022). As EFs improve, they may play a bigger role in supporting fraction performance.…”

“…One possible explanation for these varying results is that IC may be a diverse construct, and common IC tasks capture different subcomponents of this capacity. A prominent division of inhibitory constructs actually considers both Stroop and Flanker as measures of the same subcomponent, variously called “response-distractor inhibition” (distinct from resistance to proactive interference; Friedman & Miyake, 2004) or “interference resolution” (Younger et al, 2022). Based on this grouping, the disparate findings for Stroop and Flanker as they relate to rational number understanding are difficult to parse.…”