Developmental Psychology: What It Is And How It’s Applied

Updated April 11, 2023by BetterHelp Editorial Team

When some people think of developmental psychology, they may equate it with child psychology. However, this type of psychology goes far beyond childhood and covers a wide range of issues across the lifespan. Here's how today's psychologists define developmental psychology and how they use it to help people of all ages.

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What Is Developmental Psychology?

For psychologists, developmental psychology has a very specific meaning. The definition of this phrase has several components. This type of psychology:

  • Is a study of human growth, maturity, learning, and adaptation.

  • Is concerned with development, which refers to growth and change.

  • Covers the entire lifespan.

  • Recognizes several stages of development.

  • Focuses on all areas of human change, including physical, social, motivational, cognitive, intellectual, emotional, perceptual, and personality.

  • Adopts research methods to explain reasons for deficiency in both child development and adult development.

There have been several prominent psychologists engaged in developmental psychology. Some of the most prominent include Jean Piaget, Erik Erikson, Sigmund Freud, and Paul Baltes.

Where Is This Psychology Used?

Developmental psychology is used both by psychologists who specialize in it and other mental health professionals who use its concepts and techniques along with other types of psychology. It is used in places like:

  • Health clinics

  • Assisted living homes and nursing homes for the elderly

  • Group homes and clinics that serve people with developmental disabilities

  • Hospitals

  • Homeless centers

  • Mental health clinics

  • Teen rehab centers

  • Government agencies

  • Schools and universities

Major Theories Of Developmental Psychology

Several theories have been proposed to explain childhood development as well as maturity beyond childhood. Four of these theories outline progressive stages of development. These four are Freud's psychosexual stages, Piaget's four stages of cognitive development, Erikson's psychosocial stages, and Kohlberg's moral development stages. Notably, Piaget’s theory has been one of the most influential theories of human development in developmental psychology. Professional childcare professionals and therapists are the primary users of Jean Piaget psychology.

Freud's Psychosexual Development Theory

In Freud's psychosexual theory, each stage focuses on a specific body part. Conflicts arise relating to these pleasure centers. If the child resolves the conflicts successfully, they pass up to the next stage and eventually to healthy adulthood. If not, they may develop mental illness in childhood or even later in life. However, Freud's theory is far less influential today than it was decades ago. Freud's stages include:

  • The oral stage: Birth to one year

  • The anal stage: Ages one to three

  • The phallic stage: Ages three to six

  • The latent stage: Ages six to puberty

  • The genital stage: Ages puberty to death

Piaget's Four Stages Of Cognitive Development

Piaget's theory of cognitive development addresses the cognitive, or thinking, aspects of development. His theory started very simply with the assertion that children think differently than adults. Piaget's four stages of cognitive development are:

  • The sensorimotor stage from birth to age two

  • The preoperational stage from age two to six

  • The concrete operational stage from age seven to eleven

  • The formal operational stage from age twelve to adulthood.

Erikson's Psychosocial Stages

Erik Erikson developed one of the most famous theories of developmental psychology. Erik Erikson expanded on Freud's ideas to form his psychosocial development theory. One thing that's striking about Erik Erikson's psychosocial stages is that they continue through the entire lifespan. These are the stages in the development of social interaction, starting at infancy:

  • Stage 1: trust vs. mistrust (infancy)

  • Stage 2: autonomy vs. shame and doubt (early childhood)

  • Stage 3: initiative vs. guilt (preschool)

  • Stage 4: industry vs. inferiority (school age)

  • Stage 5: identity vs. confusion (adolescence)

  • Stage 6: intimacy vs. isolation (young adulthood)

  • Stage 7: generativity vs. stagnation (middle adulthood)

  • Stage 8: integrity vs. despair (old age)

At each stage, there's a conflict that must be overcome. If it is, the child or adult develops the social skills and attitudes needed for the next phase of life.

Kohlberg's Theory Of Moral Development

Lawrence Kohlberg designed a theory of moral development with three levels of morality. His theory is about moral reasoning, but not necessarily about moral behavior. He also recognized that, although a level might be most common in one age group, that doesn't mean people in other age groups don't use it. His three levels of moral development are:

  • Preconventional morality, in which moral decisions are based on obeying fixed rules.

  • Conventional morality, in which people try to be "good" and live up to socially accepted norms for behavior.

  • Postconventional morality, in which people rely on universal ethical principles, agreed-upon standards, and abstract reasoning to come to their moral conclusions.

How Developmental Psychology Can Help In Childhood

Both researchers and practicing psychologists can help children by drawing on developmental psychology. Those studying this branch of psychology in a research situation may seek to discover the typical stages and rates of development during the human lifespan. They may focus on research methods such as language acquisition, moral development, or infant development, to name a few.

Clinical psychologists can use the information learned by these researchers to help children and their parents more directly. Because they know when infants usually start walking, talking, developing moral reasoning, and venturing away from their parents' reach, they can identify possible developmental problems.

Developmental Disabilities

A psychologist can recognize when a young child needs to be evaluated for developmental disabilities. They can conduct those tests with the child and provide treatment if needed. The goal of helping people with these disabilities is to give them tools and teach them skills for dealing with their challenges and reaching their highest potential. Developmental psychologists also use several research methods to understand reasons for developmental disabilities.

Learning Disabilities

Developmental and child psychology is also helpful for identifying and treating learning disabilities, including language-related and information-processing disorders. Language-related learning disabilities include dyslexia and dysgraphia, for example. People who have information-processing disorders may have trouble recognizing, responding to, and remembering the information they get through their senses.

Developmental psychologists may help people with learning disabilities in several ways. They may work with a special education teacher to assess students and devise strategies to help them succeed in school. Or, they may help children learn through individual therapy. They often use technology and research methods to help students to overcome their learning problems.

How Developmental Psychology Can Help In Adulthood

If you're an adult seeing a therapist who uses developmental psychology, they can help you overcome problems from your past that are impacting current decisions and behaviors. Any of the stages in the developmental models discussed above may have a bearing on how you respond to today's problems and dilemmas.

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Particularly, experiences in child development can impair growth in adulthood to significant levels. One part of developmental psychology treatment may be to recognize the stage of life you're in now. As you understand your stage better, you can find acceptance for your thoughts and behaviors as they are now. Then, your therapist may guide you in reaching the next stage of development if you're ready for it. This may involve both talk therapy and homework assignments that allow you to practice new ways of thinking and behaving.

During adulthood is the time when you can be building a life for yourself and living it to the best of your ability. Your therapist may draw on developmental psychology concepts to help you make the most of your life and reach your highest potential. They may discuss topics like getting into and succeeding in college, advancing in your career, and building a family, within the context of developmental stages.

How Developmental Psychology Can Help In Old Age

While developmental psychology is integral to child development and issues of child psychology, it is also important in adulthood and well into old age, as you continue to develop, change, and adapt all throughout your life. Developmental psychologists can also study developmental issues related to aging. A developmental therapist might guide you as you think back on your life and help you positively make sense of it, or they may work with you to help you navigate the new stage of life you are in currently. 

For many in old age, a key concern can be adapting to life and routines while experiencing physical changes or challenges. This might include physical limitations, greater susceptibility to illness, and declining cognitive abilities. Because your therapist has studied these life changes, they can help you devise strategies for dealing with them on your own, building a support network, and getting and accepting help as needed.

Can Developmental Psychology Help Me?

Anyone with concerns related to life changes can benefit from talking to a therapist trained in developmental psychology. If you feel that you aren't living up to your potential, this type of therapy can help you gain the skills, knowledge, and maturity you need to reach for your highest self. Whether you choose a professional that relies on developmental psychology exclusively or one that uses it as a part of an eclectic practice, this type of psychology can help you understand yourself and others better. It can help you make the decisions and develop the skills that are most helpful to your long-term growth, health, and well-being. 

Life can pose challenges at any stage, and sometimes, it can be difficult to find a therapist who is the right match for your specific concerns given your unique situation. With online therapy through BetterHelp, you can match with a therapist based on your unique needs and preferences, all from the comfort of your home, or wherever you have an internet connection. 

Individuals at any stage may experience a variety of concerns and conditions, such as anxiety, depression, stress, OCD, and more, and research has shown that online therapy can be just as effective as in-person therapy for a range of concerns.


Developmental psychology is a study of human growth, maturity, learning, and adaptation that covers the entire lifespan. It can be used in a variety of settings to help people of all ages. If you are interested in connecting with a therapist for support with your growth and development, you may consider online therapy. 

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