Developmental Psychology

If you’re here, you’re probably interested in or doing some research for developmental psychology. Have no fear, because on this page you’ll find a huge resource to everything there is to learn on the subject!

How did you become the person you are today? What roles did your parents play in this development? Could they have done anything to make you a smarter, calmer, more aggressive, or more successful person? Or does their input not matter in the grand scheme of things? Is your development all based on what is in your genetic code? 

These answers can have a significant effect on how you view personal development and even your self-esteem. If you believe you have control over your development, you may feel more confident enrolling in personal development courses or even changing the course of your life. Without control, what can we do to improve ourselves and improve the generations after us? 

I know these are big questions that often have complicated answers. Developmental psychology is a huge topic that covers many different theories, debates, and areas of research. This video is all about developmental psychology and the people who have shaped this field since the 1800s. I’ll go over the ways in which we develop, theories surrounding these areas of research, and the biggest questions that developmental psychologists are still trying to answer. There is a lot to cover in one video, so buckle up!

What Is Developmental Psychology?

Developmental psychology is the study of the way that humans change, develop, and evolve over the course of their life. The study of the change of the brain from birth to death has exploded with research in the past few decades.

Since there are so many different areas of developmental psychology out there, we are going to break it down for you.  

Types of Development Studied

Between the time we are born and the time we become an adult, we have developed in many different ways. We have acquired many skills. We understand more about the world. We understand more about ourselves. 

Developmental psychology takes a look at all of the ways that we develop and age, including:

  • Cognitive development
  • Language development
  • Social development 
  • Development of sense of self and self-esteem
  • Emotional development 
  • Moral reasoning 
  • Personality development 

Basically, developmental psychology helps us understand how we become the person that we are. If there are shortcomings or developmental difficulties, these theories can help us pinpoint where things came up short and how a person can recover. 

What Are the Most Well-Known Theories in Developmental Psychology? 

Psychologists have been studying different forms of development since the late 1800s. German psychologist Wilhelm Preyer has been credited as one of the first developmental psychologists. Preyer wrote a book in which he reflects on observing his child from birth until the age of 2 ½. 

While many psychologists began to observe children, it wasn’t long before the connection was made between child development and adult behavior. The theories that define developmental psychology today do more than just talk about children. From these theories, we can gain insight into our adult decisions, behaviors, and relationships. 

Jean Piaget’s Theory of Cognitive Development 

Let’s start by talking about Piaget’s Theory of Cognitive Development. Jean Piaget was a child psychologist who observed subjects from birth until adolescence. At different ages, Piaget noted that the child developed different cognitive skills. Object permanence, for example, is the understanding that people, places, and things still exist outside of your line of vision. Piaget observed that children develop object permanence between the age of 4-7 months. 

Piaget laid out a series of stages in which cognitive development occurs. These stages last until a child reaches the age of 12.  

Lawrence Kohlberg’s Theory of Moral Development 

Piaget’s work was extremely influential in the world of developmental psychology. Lawrence Kohlberg, for example, expanded upon Piaget’s theory to create his own Theory of Moral Development. This theory involves three stages. At each stage, a person uses different sets of reasoning to make moral judgements and assess what is “just.” 

Sigmund Freud’s Theory of Psychosexual Development

Like Piaget, Sigmund Freud also developed a theory of development that involved a series of stages. While most of the stages occured in childhood, Freud’s latent stage takes place from puberty until a person’s death. 

But there are some very significant differences between Freud’s theory and Piaget’s theory. Freud’s theory is concerned with a child’s psychosexual development. At each stage, the child’s id is focused on a different erogenous zone. The child will experience different conflicts that end up shaping their personality. If the conflicts are overcome and the stage is successfully completed, the child will develop a healthy personality. If there are lingering issues, the child is likely to develop a fixation associated with that stage’s erogenous zone. 

​Erikson’s Theory of Psychosocial Development

Have you ever heard of the term “identity crisis?” It’s common for many people to experience an identity crisis around adolescence, when they are figuring out just who they are and their role in the world. This idea was developed by Joan and Erik Erikson, two German-American psychologists who developed the Theory of Psychosocial Development. According to Erikson, there are eight stages of psychosocial development that last from birth until old age. In each stage, a person goes through a crisis. Can they trust the world that they live in? Are they free to take action when they want to? Can they build a supportive network of friends or family? If the stage is completed, the person gains a basic virtue (love, hope, etc.) Failing to complete this stage can cause insecurity later on in life. 

Other Theories on Learning And Development 

Not all theories in developmental psychology outline stages of a person’s life. Some theories in developmental psychology merely categorize children and adults by the way in which they have developed. Or these theories look at the ways in which children learn about the world and relationships. 

Attachment Theory 

How do you learn how to be in a relationship: romantic, platonic, or otherwise? Many psychologists and therapists believe that you learn these skills from the relationship you have with your parents. Psychologists John Bowlby and Mary Ainsworth observed children as they interacted with both strangers and their parents. Some children felt secure interacting with both groups. Others showed signs of anxiety or detachment. This led to the creation of the four different Attachment Styles:

While this theory began by observing children, Attachment Theory can help adults assess their own relationships and how they develop (or don’t develop) a secure attachment to their partners. 

Lev Vygotsky’s Zone of Proximal Development

Developmental psychology doesn’t just look at the way we relate to others. Many theories on learning in the classroom also stem from developmental psychology. Lev Vygotsky was a psychologist that observed how people learned new skills. He theorized that skills could be categorized in three stages: skills that a person could do without any help, skills that were impossible for a person to do without assistance from another, and skills that required some guidance from a more knowledgeable other (MKO.) This last zone included skills that were just a “step up” from skills they had already learned and acquired. This zone is known as the Zone of Proximal Development, or ZPD. Every student’s ZPD is unique to their own skill set.  

Vygotsky is also associated with the theory of Scaffolding, but he never coined the term himself. He created the theory of ZPD in the last three years of his life. His work, however, has become extremely influential to psychologists around the globe. Here’s my article to learn more about the Zone of Proximal Development

Behavioral Development Theory 

Let’s say that as a child, you look up at the sun. It hurts your eyes. You aren’t likely to look at the sun again, right? 

Or, let’s say you use the toilet properly and your parents give you candy. You’re going to want to use the toilet properly again, right? 

A lot of our learning comes from rewards and punishments. We like to be rewarded. We don’t like to be punished. When we associate an action with a reward, we are encouraged to do it again. 

This simple idea is where developmental psychology really began. John B. Watson was a behavioral and developmental psychologist that helped to develop the school of behaviorism. Utilizing the work of psychologists like B.F. Skinner and Ivan Pavlov, behaviorism became one of the leading theories in psychology. It came from well-known experiments like Pavlov’s experiments with dogs. 

These theories concluded that children learned behaviors and lessons through a series of associations and reinforcements. 

Albert Bandura’s Social Learning Theory 

The last theory I’m going to mention is Bandura’s Social Learning Theory. How do children learn? Sometimes, they go to school. Or, they learn through the conditioning that we just discussed. Bandura’s theory says there is more than just conditioning or textbooks. He says that children learn about the world merely through observation and modeling. His Bobo Doll experiment is one of the most famous experiments in developmental psychology. It showed that children who observed an adult being more aggressive were more likely to display aggressive behaviors. The things that a child sees, hears, and observes, Bandura concluded, will have a significant impact on the decisions the child makes and the behaviors they display. 

Debates in Developmental Psychology 

Theories within developmental psychology address different forms of development throughout a person’s life. However, these theories attempt to answer some general overarching questions about how we develop. 

These questions are often framed as debates. The three main debates within Developmental Psychology include: 

  • Nature vs. nurture
  • Continuity vs. discontinuity
  • Stability vs. change

Nature vs. Nurture 

What causes us to develop in one way or another? Is it the way our parents raise us? The media that we consume? The culture we grow up in? Or is it simpler than that? Can we look at genes and hereditary factors that determine our development? 

These are the questions within the nature vs. nurture debate. Nativists, on one side of the spectrum, believe that the answers to developmental psychology can be found in our biology. That genes can determine our personality and behavior. 

On the other side of the debate are empiricists. They believe that nurture determines everything. The way a child is raised will determine how it behaves as an adult (Attachment Theory is an example of a theory that relies heavily on nurture.) 

This debate has a heavy influence on parenting styles or how we assess people with particularly “bad” behavior. Do children have violent personalities because of genes, for example, or is it because they were allowed to play violent video games as a young age? 

Continuity vs. Discontinuity

You might have noticed that a lot of theories mentioned above lay out different stages of development. Freud maps out stages of psychosexual development. Erikson’s theory has stages of psychosocial development. Is that how development really works? 

That’s another big question that developmental psychologists want to answer. These stages contribute to the idea of discontinuity. The discontinuity view maps out different stages and problems that children (or adults) go through when they reach a certain age. Not all children (or adults) go through these stages at the same rate, but everyone goes through these stages in the same order. 

On the other side of this debate is the continuity view. If discontinuity was a series of steps, continuity is a ramp. The continuity view sees development as something that children go through based on their current skills and knowledge. They continue to build these skills as they would grow taller. 

One idea associated with the Zone of Proximal Development is scaffolding. Scaffolding is the idea that children learn certain skills and then begin to build on top of those skills, like climbing a ladder. This is similar to the idea of continuity. Each child has their own ladder and develops at their own pace.   

Stability vs. Change

Have you ever heard a new parent say that their baby has a calm personality? Or they believe that their child has always been curious? This talk might just be from excited parents – or is it? 

The last debate that I’m going to talk about is stability vs. change. Do we have a stable personality that is established from the moment we are born? Or can the troublesome baby grow into a rule-abiding child? 

The environment a child grows up in, or care from parents, could influence a child’s personality – if personalities are subject to change. And while this sounds like the nature vs. nurture debate, it’s not exactly the same. Psychologists believe that personalities may change due to external factors, like parenting styles or trauma. They may also believe that personalities change due to maturation and internal factors. 

Ages Observed in Developmental Psychology

A lot of developmental psychologists observe infants and children as they develop into teenagers and adults. But developmental psychology is about more than just kids. Even the “nature vs. nurture” stage impacts how adults may approach personal development and change. Adults that become parents are certainly affected by developmental psychology: the approach they use to parent their children is often influenced by what psychologists say is “right” or “wrong” for a child’s development. 

And in some theories, like Erikson’s Stages of Psychosocial Development, we continue to develop and gain new virtues well into our 60s, 70s, and 80s. 

This is why it’s so interesting to pay attention to these theories of development. Using the information gathered by developmental psychologists, you may be able to reflect on your own development and see where things may have gone “right” or “wrong.” If you find yourself having problems being too “clingy” in relationships, attachment theory might be able to give you insight as to why. If you have trouble taking control over your actions and taking initiative, Erikson’s theory may help you understand why. If you just want to learn something new, the Zone of Proximal Development suggests to start building off of what you already know. 

Remember, these are all theories of development. Nothing is set in stone. But these theories are definitely interesting to learn about, and these debates are fun to explore!

Practical Psychology

Practical Psychology began as a collection of study material for psychology students in 2016, created by a student in the field. It has since evolved into an online blog and YouTube channel providing mental health advice, tools, and academic support to individuals from all backgrounds. With over 2 million YouTube subscribers, over 500 articles, and an annual reach of almost 12 million students, it has become one of the most popular sources of psychological information.

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