June 24, 2024

Developmental psychology is the study of how humans grow, change, and adapt across the course of their lives. Developmental psychologists research the stages of physical, emotional, social, and intellectual development from the prenatal stage through infancy, childhood, adolescence, and adulthood.

This article covers developmental psychology, including the definition, types, life stages, and how to seek treatment when necessary.

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Defining Developmental Psychology

According to the American Psychological Association (APA), developmental psychology is a branch of psychology that focuses on how human beings grow, change, adapt, and mature across various life stages. Developmental psychology is also known as human development or lifespan psychology.

In each of the life stages of developmental psychology, people generally meet certain physical, emotional, and social milestones. These are the major life stages, according to developmental psychologists:

  • Prenatal development: Developmental psychologists are interested in diagnoses, such as Down syndrome, that might be noticed during the prenatal (before birth) stage. They also investigate how maternal behaviors (behaviors of the pregnant parent), such as nutrition and drug use, could affect the developing fetus.
  • Early childhood: Developmental psychologists are interested in whether young children are meeting key milestones, such as walking, talking, and developing fine motor skills (coordination in the hands, fingers, and wrists). They might also be interested in a child’s attachment to their parents and other caregivers.
  • Middle childhood: In this stage, children learn about the world and acquire knowledge through experimentation, questioning, and observation. They begin to develop logical and moral reasoning skills.
  • Adolescence: Adolescence is a time of major strides in terms of personal development and identity formation. Teens and young adults might experiment with various identities, career choices, or areas of interest.
  • Early adulthood: During early adulthood, most people are focused on preparing for the rest of their lives through a focus on education, career, and financial independence. Romantic relationships, marriage, family-building, setting down “roots,” and child-rearing are often a focus of this life stage.
  • Middle adulthood: Middle-aged adults are often focused on helping the next generation, whether in their own family or their community. They are also often interested in the legacy they’ll leave behind.
  • Older adulthood: In addition to physical health challenges, older people might face issues like dementia or cognitive decline (decline in thinking, remembering, and reasoning). Older adults also often need to reflect on their lives, tell their stories, and find meaning and peace within the aging process.

The Origins of Developmental Psychology

During its early development as a branch of psychology in the late 19th and early 20th centuries, developmental psychology focused on infant and child development. As the field grew, so did its focus. Today, developmental psychologists focus on all stages of the human lifespan. 

Theories of Developmental Psychology

As developmental psychology grew over time, various researchers proposed theories about how to understand the process of human development. Depending on their training, a developmental psychologist might focus on a specific theory or approach within the field. 

These are a few of the major branches of developmental psychology.

Psychosocial Developmental Theory

Building on Austrian neurologist and the founder of psychoanalysis Sigmund Freud’s theory of psychosexual development, psychologist Erik Erikson proposed a lifespan theory that included eight stages of psychosocial development.

Each of the stages corresponds to both an age range and a core “crisis” (such as trust vs. mistrust in infancy) that must be resolved before someone can move on to the next.

Cognitive Developmental Theory

Swiss psychologist Jean Piaget’s theory of cognitive development focuses on how children and youth gradually become able to think logically and scientifically. Piaget proposed that cognition develops through four distinct stages of intellectual development, beginning at birth and ending at age 12.

Attachment Theory

Attachment theory, originally developed by psychoanalyst John Bowlby, establishes the importance of a supportive, steady, and loving caregiver in infant and child development. If a child doesn’t establish such a connection, or if they experience parental separation or loss, they might continue to struggle with healthy attachments as they get older.

Sociocultural Developmental Theory

While Bowlby considered the importance of the immediate family in child development, psychologist Lev Vygotsky’s sociocultural developmental theory looks at the role of society. Cultural influences and beliefs can have a profound impact on how a person views their own identity and relates to others.

Conditions Treated

Developmental psychologists can help people address developmental issues in order to reach their full potential. 

Some of the conditions a developmental psychologist might treat include:

  • Learning disabilities
  • Intellectual disabilities
  • Developmental delays
  • Motor skill delays
  • Issues with social and emotional development
  • Auditory processing (hearing) disorder
  • Autism spectrum disorder (ASD)
  • Speech and language delays
  • Dementia
  • Mental health conditions like anxiety and depression, especially related to life stages

Training and Certifications

The training required to become a developmental psychologist is similar to that in other subfields of psychology. Most developmental psychologists start with an undergraduate degree in psychology or a related field, followed by a master’s degree and a doctoral degree (PhD). 

There are many master’s, graduate certificate, and PhD programs in developmental psychology in the United States. Some focus on a certain part of a person’s lifespan, such as child and adolescent development. In addition to research and teaching, graduates may participate in a practicum or internship to pursue licensing as a therapist. 

When to Seek Treatment

If you’re concerned that your child is facing a developmental delay, a developmental psychologist can assess them to ensure that they are meeting their milestones. It’s best to seek an assessment, diagnosis, and treatment early, so intervention can begin as soon as possible.

Examples of when to see a developmental psychologist may include:

  • An infant is struggling to bond with their parents.
  • A toddler is missing milestones, such as walking or developing speech.
  • A school-aged child is not progressing appropriately in reading or writing.
  • An adolescent is facing challenges related to social and/or emotional development.

A developmental psychologist might perform physical and/or cognitive testing to diagnose your child or refer them to another specialist, including the following:

  • Physical therapist (helps people improve movement and manage pain)
  • Occupational therapist (helps people adjust to everyday activities after injury, illness, or disability)
  • Speech-language pathologist (treats speech, language, and social and cognitive communication)
  • Psychotherapist (uses talk therapy to treat mental health conditions)
  • Neurologist (medical doctor who treats disorders of the brain, spinal cord, and nerves)
  • Psychiatrist (medical doctor specializing in mental health conditions)

A developmental psychologist will also likely ask you and your child questions about issues in areas of their life such as friends, behavior, or school performance.

In addition to working with infants and children, developmental psychologists can also help people at any stage of life. In particular, many older adults benefit from working with a developmental psychologist if they’re experiencing symptoms of dementia, ill health, or cognitive decline.


Developmental psychology is the study of how human beings grow and change throughout their lives. Many developmental psychologists focus on the intellectual, social, emotional, and physical development of infants, children, and adolescents. Others treat and assess people of all ages. 

Developmental psychologists can treat issues such as developmental delays, intellectual disabilities, learning disabilities, speech and language delays, motor skill delays, dementia, anxiety, depression, auditory processing disorder, autism spectrum disorder, and more. They also make referrals to other specialists, such as physical therapists, psychiatrists, and speech-language pathologists. 

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

By Laura Dorwart

Laura Dorwart is a health journalist with particular interests in mental health, pregnancy-related conditions, and disability rights. She has published work in VICE, SELF, The New York Times, The Guardian, The Week, HuffPost, BuzzFeed Reader, Catapult, Pacific Standard, Health.com, Insider, Forbes.com, TalkPoverty, and many other outlets.


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