Piaget’s Stages of Development 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 theories, the stages of psychosocial development Piaget proposed remain salient. In fact, it is easy to combine emerging research on childhood development from infancy to adolescence in terms of Piaget’s stages. 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 discreet stages with strong demarcations between them, empirical research in cognitive, behavioral, and biological sciences have shown that indeed children do exhibit specific features of psychosocial, cognitive, and physical development during the age brackets Piaget had observed.

Infancy: The Sensorimotor Stage

The first few years of life prove critically transformative for childhood development physically, cognitively, and even socially and emotionally. In fact, research shows that infants do already have 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). Therefore, research on infant cognition and perception 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 are developing their sensorimotor skills by engaging with objects, particularly by 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...

Infants demonstrate the ability to form social attachments and exhibit individualized emotional responses, too, with differences depending on environmental factors like parental behavior and culture (Lightfoot, Cole & Cole, 2009. While their ability to understand and use language has yet to emerge, at this early developmental stage infants do communicate using nonverbal communication including crying and the use of facial expressions.
However, the most striking features of infant development is on the physical level, with major shifts in the child’s biology. The rapid growth of the brain and central nervous system, for example, is also 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 the ways the bones and muscles are developing, dependent of course on nutrition and also genetics (Britto, Lye, Proulx, et al. 2017).

Toddler and Early Childhood: The Preoperational Stage

The next stage in Piaget’s model of childhood development is known as the preoperational stage. During this stage, the child exhibits increasing sophistication in terms of emotional, psychological, and cognitive skills. Through observation and social learning, the toddler comes to understand which emotional expressions are socially acceptable or approved and which are not, leading to the ability to “elaborate,” and even control emotional responses in the first real demonstration of self-mastery (Labouvie-Vief, 2015, p. 67). Self-mastery behaviors are also evident in the way the child is starting to control bodily functions like toilet 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 the burgeoning awareness of morality and social norms (Lightfoot, Cole & Cole, 2009, p. 287). While the early stages of empathy development may begin in infancy when the child actually responds in kind when hearing another baby cry, it is during early childhood that empathy, altruism, and prosocial behaviors really take root (Demetrious, 2018; Lightfoot, Cole & Cole, 2009).

These important psychological and cognitive shifts in early childhood occur in accordance with language skills development: which is one of the cornerstones of the preoperational stage. In addition to…