6.2 Executive functions emerge in early childhood

Objectives:

A. Understand that EFs differentiate early in life and are evident in child behaviour.

B. Appreciate that new measurement tools and a surge of research during the 1990s began improving our understanding of how EFs develop and prepare children for school.

At age 6, most children are still mustering full attention to tie their shoelaces. But only a few years later, many of them will be able to tie a shoe while balancing on the other leg and maintaining eye contact and conversation with a friend. We may conclude that with time and practice, even a complex routine can become habitual, which only means that the motor plan has been automatized and stored in a way that execution will require minimal wherewithal. Parents and caretakers report that children are quite adept at routinizing complex behaviours to the point of automaticity, or nearly so. Most children are highly motivated. Indeed, it’s a point of pride to tie one’s own laces, write one’s name, carry out a morning routine alongside parents, ride a bike, pronounce the word “thumb” the way everyone else does, and so on.

There are times, however, when reliable habits are not enough. Sometimes a novel situation will call for a flexible response, and an experienced individual will know when there is sufficient time to pause and reflect with purpose. On these occasions, habitual and impulsive responses are in fact voluntarily resisted, allowing higher-order networks to factor previous experience and evaluate the situation. A goal-directed behavioural response can then be planned and not only enacted but controlled. Put another way, our executive functions help us inhibit automatic or inappropriate responses, hold goal-relevant information in mind, and flexibly shift our focus of attention in timely, goal-oriented ways. Coordinating these EF behaviours has been compared to the work of a symphony conductor, an air traffic controller, or a chief executive officer, and it plays a vital role in all areas of everyday life and independent living. In fact, many studies have hailed EF as factoring in school and job success, wellness and physical health, marital relations, and quality of life (Cristofori et al., 2019).

But EF capabilities are not present at birth. They emerge with maturation and experience during early childhood, through capacity-stretching sensorimotor processes and achievements such as learning to move the eyes voluntarily and reaching. Remember, the everyday world of a growing toddler is full of inaccessibility and oversized physical demands: heavy objects, racing caretakers, complex tasks, unanticipated events, and so on. It takes time for children to learn to operate in that sort of world, a world that is still substantially unfamiliar, and the effort involved in the most modest attainments can visibly tire or frustrate. Whereas mature executive functioning is largely “mentalized” and hidden away in adults, that is not yet the case with young children. When we observe the best efforts of children to think and plan and monitor and control themselves, we see their attentional efforts reflected in the use of the hands, body, voice, face, and brow. No doubt about it, learning to develop and coordinate EFs is effortful and, what’s more, it is typically embodied in some way and therefore observable. We might add at this time that EFs are often referred to as skills because they (a) rely on specific brain networks, (b) are acquired with use, and (c) enable adaptive behaviour (Zelazo, 2015; Perone, 2018).

During the 1990s, several factors contributed to a sharp increase in studies investigating EF development in children (Garon et al., 2008). For one, research findings were clarifying that the prefrontal cortex is active during infancy. It’s true that many other brain areas connect to and influence EF networks, but the prefrontal lobes have long been considered the hub of our higher-order functions. A second reason was that a number of researchers in the field were working to adapt adult EF tasks for use with children. Many new age-appropriate tasks were also being created for young children. By the time Miyake et al. (2000) published their three-component model of executive functioning, developmental researchers had the tools and interpretive framework they needed to generate theory-driven hypotheses, design gainful studies, and advance understanding.

Following Miyake et al. (2000), many studies attempted to clarify how specific EF skills emerge during early childhood. For our present purposes, key findings can be summarized as follows. First, evidence suggests the three-component model does not provide the best fit for very young children (Garon et al., 2008; Wiebe et al., 2011; Willoughby et al., 2012). Although the core components of Updating, Inhibition, and Shifting appear in sequence by the age of three and slowly develop on unique trajectories, they are still weakly differentiated. Analyses show that executive functioning in preschoolers presents as more of a singular entity. Then, between 3 and 6 years of age, we see both increasing differentiation and rapid improvement in EFs. Those developments are thought to be due to a common, maturing central attentional system (Posner & Rothbart, 1998; Rothbart & Posner, 2001). They drive the gradual appearance of higher-order EFs (e.g., planning, goal setting, problem-solving), emotional regulation (e.g., empathizing, managing emotions and behaviour), and social skills (e.g., working with others, reading social cues, cooperating). These skills make substantial contributions to school readiness, the set of skills and capacities that preschoolers need for a successful transition to school.

In the following sections, we will take a closer look at each of the three core components

of executive function—Updating, Inhibition, and Shifting—and how they reveal themselves in early classroom settings.