Piaget's Four Stages of Child Development Explained

Introduction

Few theorists have had as strong an impact on developmental psychology as Jean Piaget. While the theories of Lev Vygotsky have offered compelling counterpoints to Piaget's work, the stages of psychosocial development Piaget proposed remain highly relevant. In fact, it is straightforward to situate emerging research on childhood development—from infancy to adolescence—within Piaget's staged framework. As Lightfoot, Cole & Cole (2009) point out, evolutionary theories, information processing theories, and systems theories can all be integrated within the staged concept of development that Piaget proposed. Piaget shows how children develop physically, socially, and cognitively. Likewise, theories of childhood development can demonstrate how children develop self-awareness, empathy, and complex use of language.

The four main stages of development include the sensorimotor, the preoperational, the concrete operational, and the formal operational. While far from being discrete stages with strong demarcations between them, empirical research in cognitive, behavioral, and biological sciences has shown that children do indeed exhibit specific features of psychosocial, cognitive, and physical development during the age brackets Piaget observed.

Infancy: The Sensorimotor Stage

The first few years of life prove critically transformative for childhood development physically, cognitively, and even socially and emotionally. Research shows that infants already possess self-awareness and "are capable of demonstrating already a sense of their own body as a differentiated entity: an entity among other entities in the environment" (Rochat, 2003, p. 717). Self-awareness during infancy is mainly body-related, linked to the ability of infants to differentiate between self-oriented touch and being touched by others (Rochat, 2003). Research on infant cognition and perception therefore substantiates Piaget's claim that sensorimotor mastery is the key goal of this stage of childhood development. Piaget claimed that during the sensorimotor stage, infants gain knowledge of the world and themselves by "coordinating sensory perceptions and simple motor responses" (Lightfoot, Cole & Cole, 2009, p. 144).

Research in biology and human development shows that infants develop their sensorimotor skills by engaging with objects, particularly through reaching and grabbing (Rochat, 2003). Also evident at the sensorimotor stage is the infant's ability to learn via both classical and operant conditioning, such as with the introduction of stimuli to induce specific behavioral responses (Lightfoot, Cole & Cole, 2009). Infants also demonstrate the ability to form social attachments and exhibit individualized emotional responses, with differences depending on environmental factors such as parental behavior and culture (Lightfoot, Cole & Cole, 2009). While the ability to understand and use language has yet to emerge at this early developmental stage, infants do communicate using nonverbal means, including crying and facial expressions.

The most striking features of infant development are physical, with major shifts in the child's biology. The rapid growth of the brain and central nervous system is paralleled by corresponding changes in the ways the child processes and responds to sensory input (Lightfoot, Cole & Cole, 2009). Infants also exhibit rapid changes in bone and muscle development, dependent on nutrition and genetics (Britto, Lye, Proulx, et al., 2017).

Toddler and Early Childhood: The Preoperational Stage

The next stage in Piaget's model is known as the preoperational stage. During this stage, the child exhibits increasing sophistication in emotional, psychological, and cognitive skills. Through observation and social learning, the toddler comes to understand which emotional expressions are socially acceptable and which are not, leading to the ability to "elaborate" and even control emotional responses—the first real demonstration of self-mastery (Labouvie-Vief, 2015, p. 67). Self-mastery behaviors are also evident in the way the child begins to control bodily functions such as toileting, as well as aggressive responses (Lightfoot, Cole & Cole, 2009). The child is developing an "early understanding of the relationship between mental states and behavior," which also leads to a burgeoning awareness of morality and social norms (Lightfoot, Cole & Cole, 2009, p. 287). While the early stages of empathy may begin in infancy—when a child responds in kind upon hearing another baby cry—it is during early childhood that empathy, altruism, and prosocial behaviors truly take root (Demetriou, 2018; Lightfoot, Cole & Cole, 2009).

These important psychological and cognitive shifts in early childhood occur alongside the development of language skills, one of the cornerstones of the preoperational stage. In addition to growing awareness of emotions and how they affect others in their social sphere, the child is developing more sophisticated self-awareness and self-consciousness (Labouvie-Vief, 2015). Interestingly, the child at this stage also begins to recognize the difference between inanimate and animate objects (Lightfoot, Cole & Cole, 2009). The preoperational stage is physically defined by the evolution of fine motor skills. Socialization becomes critical during this period, and while the beginnings of an individuated personality appear in the sensorimotor stage, that personality becomes more cohesive during early childhood. The child starts to construct identity based on individual and external cues (Lightfoot, Cole & Cole, 2009), and that identity may be influenced by constructs such as gender and ethnicity.