Skip to ContentGo to accessibility pageKeyboard shortcuts menu
OpenStax Logo
Psychiatric-Mental Health Nursing

2.6 Developmental Theories and Therapies

Psychiatric-Mental Health Nursing2.6 Developmental Theories and Therapies

Learning Objectives

By the end of this section, you will be able to:

  • Define developmental theories and therapies
  • Identify nursing application of developmental theories and therapies

Psychiatric-mental health nurses can utilize concepts from developmental theories to enhance their awareness of the client’s experience. This knowledge informs client education as well. Nurses may apply cognitive development theory when observing the client’s interactions with the environment, whether in treatment or in the community. The theory of object relations empowers nurses to recognize and analyze cues in the client’s presentation and expressed needs, which leads to focused care planning. Moral development theory informs nurses when ethical questions arise. All theory application contributes to the nurse’s self-awareness and effectiveness in client care. This section covers theories of Jean Piaget, Margaret Mahler, and Lawrence Kohlberg.


Developmental theories seek to explain the process of a child’s understanding. This process is investigated as occurring in steps or stages, or in a continual way through the life span.

Jean Piaget

Jean Piaget (1896–1980) was a Swiss psychologist and researcher. Piaget worked in a boys’ school and scored the intelligence exams given to the boys, noting that younger children would consistently give incorrect answers to the same questions the older children would answer correctly. This brought him to conclude that cognitive development was a dynamic process with primitive awareness and recognition to a more complex manner of thinking. He found that the mental representation of the world or process of information depended on the cognitive stage humans reached and mastered (Scott & Cogburn, 2023). The theory had four stages of development: sensorimotor, preoperational, concrete operational, and formal operational. Table 2.6 describes these stages.

Stage Ages Description
Sensorimotor Birth to 2 years Basic reflexes through purposeful movement, spatial abilities, and hand-eye coordination. The physical interaction provides the child with understanding of the environment. Around nine months, the concept of object permanence is mastered. This means the child is able to believe an object exists after the first encounter.
Preoperational 2–7 years Egocentric thinking where the child thinks in concrete terms, not in the abstract. They expect others to see the world as they do. They cannot conceptualize qualities without specific objects to show this. They are unable to comprehend, for instance, that the same amount of (mass, volume, or number) liquid can be stored in a tall, thin glass as a short, wide glass.
Concrete Operational 7–11 years Logical thinking starts and abstract thinking is possible. Diversity of thought is possible, and the child can see multiple ways to solve problems. The ability to understand classification, sorting with distinct differences, creating patterns, and the concept of reversibility.
Formal Operational 11 years to adulthood Conceptual reasoning starts at the same time as puberty. Problem-solving and abstract thinking are the same abilities as an adult.
Table 2.6 Piaget’s Cognitive Development Stages (Scott & Cogburn, 2023)

Piaget’s concepts are utilized in therapies in educational settings, especially with children.

Margaret Mahler

The theory of object relations, according to theorist Margaret Mahler (1897–1985), is how a person relates to the world according to their past relationships. Specifically for the infant, the mother or significant other becomes one with the child. The infant cannot conceptualize the mother’s permanence when the two are apart, which is known as the concept of object constancy. Therefore, in the infant’s understanding, the mother does not exist when not physically present. A variation of other theories, Mahler places less emphasis on primitive human drives and more importance on consistent relationship patterns.

Mahler believed that psychological problems were related to the disruption in separation from the object (Blom, 2018). She studied the process of how infants move from total self-interest to struggle with separation from the mother, to becoming a physically and psychologically differentiated toddler (Table 2.7). This natural healthy process is developed by the object, that is, the parent/significant person, allowing the child to wander off in a safe environment while staying close by so the child is assured the parent is still present. Over time and over exposure to this type of experience, the child begins to trust the process and become an individual. Another important piece of exposure is to reward the child when they return to the mother. This reward is a verbal or other sensory affirmation that reinforces the action was good. Mahler also believed that “perfect parenting” was not necessary for this transitional trust to develop.

Mahler’s concepts are utilized in therapies by recognizing that individuation is a complex process (Blom, 2018). Treatment approaches factor into therapy with families who experience periods of transition such as a new baby, a child beginning school, or a young adult leaving home. Mahler’s framework guides assessment of individual growth. Couples therapy explores separation-individuation, recognizing that personality development occurs throughout the life span.

Stages of Development Infant’s Behaviors
Autistic stage: (0–1 month) Infant’s focus is self
Mother/caregiver is one with the infant, not existing separately
Symbiotic stage: (1–5 months) Infant begins to realize mother/caregiver’s separate existence and main source of support
Separation-individuation stage: (5–24 months)
Infant’s focus shifts to difference between self and mother/caregiver
Motor skills develop, allowing physical separation
Infant explores environment, though remains dependent on mother/caregiver
Infant begins to fear loss of mother/caregiver and must learn to balance dependence with independence, i.e., “terrible two’s” as infant tests new behaviors, resulting in development of self-concept
Table 2.7 Mahler’s Stages of Child Development (Grace, 2019)

Lawrence Kohlberg

Psychologist Lawrence Kohlberg (1927–1987) expanded upon Piaget’s cognitive stages by establishing moral stages. His theory of moral development provides a framework of three levels and six stages for understanding the progression a child develops when learning right from wrong (Smith, 2023).

The first level, preconventional, has two stages. This level is distinguished by rules and listening to authority. During the first stage, punishment and obedience, the child learns obedience is the way to avoid punishment. The second stage is instrumental purpose orientation. In this stage, the child sees that others look at rules differently and if they choose to not follow the rules, they risk punishment.

The second level, conventional, has stages three and four. The third stage is good interpersonal relationships. In this stage, the child begins to start using motivation and personality as reason for following or not following the rules. The child thinks in terms of “good and bad” as a person who gets along with others. Stage four is maintaining the social order. The person becomes aware of the fact “rules are rules.” People all must fall in line with these, not only to avoid punishment, but because of the broader view of society. The person begins to see that following authority maintains social order. The person sees this in large systems, such as government and corporations.

The postconventional level houses stages five and six. Stage five is social contract and individual rights. In stage five, the person believes that social order is good and correct. Stage six is universal ethical principles. The overarching sentiment here is that actions should create justice for all who are involved, and, as a society, people are obliged to break unjust laws/rules.

Kohlberg’s concepts are utilized in therapies to help explain that people can have different reactions to similar ethical concerns. Kohlberg’s theory can guide parents and caregivers as children develop their own moral framework and, ultimately, learn about social expectations.

Nursing Application of Developmental Theories

Developmental theories help the nurse know how to assess, intervene, and evaluate the client. These theories help the nurse develop approaches to client care based on clients’ developmental levels, regardless of chronological age. These levels are multilayered and unique with each client.

Nursing Application of Cognitive Development Theory

Nurses’ understanding of basic principles of human growth and development allows focused care planning, especially for teaching. In addition, nursing expectations for client responses can be realistic and provide situations wherein clients can receive positive feedback for accomplishments. Because interaction with the environment is important to human development, the nurse acts as milieu manager in hospital settings and promotes healthy public communities through advocacy and consulting.

Nursing Application of Object Relations Theory

When nurses learn the client’s history, an understanding of childhood experiences may provide cues to client behaviors, emotions, and coping ability so the nurse gains the knowledge to plan appropriate care. For nurses themselves, object relations theory gives opportunities for self-awareness. Nurses may experience reactions to client care scenarios that are unexpected or confusing. These situations can prompt the nurse to seek mentoring or feedback from colleagues.

Nursing Application of Moral Development Theory

Moral development theory can assist nurses to understand clients’ reasoning and decision-making. By understanding where clients fall in the stages of moral development, the nurse can customize their care to what the client requires. Understanding these theories allows the nurse to appreciate the importance of their own moral compass. Nurses often come across ethical dilemmas when interfacing with clients. Kohlberg’s theory can contribute to a more educated approach to these dilemmas because it illuminates the level of moral reasoning of all parties involved in the situation, including clients, loved ones, and other health-care providers.


This book may not be used in the training of large language models or otherwise be ingested into large language models or generative AI offerings without OpenStax's permission.

Want to cite, share, or modify this book? This book uses the Creative Commons Attribution License and you must attribute OpenStax.

Attribution information
  • If you are redistributing all or part of this book in a print format, then you must include on every physical page the following attribution:
    Access for free at
  • If you are redistributing all or part of this book in a digital format, then you must include on every digital page view the following attribution:
    Access for free at
Citation information

© Jun 25, 2024 OpenStax. Textbook content produced by OpenStax is licensed under a Creative Commons Attribution License . The OpenStax name, OpenStax logo, OpenStax book covers, OpenStax CNX name, and OpenStax CNX logo are not subject to the Creative Commons license and may not be reproduced without the prior and express written consent of Rice University.