Psychology 101: Intro to Psychology

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Why do we study psychological development? People change over their lifetimes, and developmental psychology helps us explore what changes and what stays the same. Learn about some of the big names in this field whose work and theories you'll explore in other lessons

Did you know that, when you leave a 5-month-old in its crib and leave the room, the baby probably thinks you've literally disappeared? Very young babies don't understand that the people and objects they observe in the world exist even when unseen. Why do babies make this mistake? When do they begin to understand that their parents do not disappear when they leave the room?

Questions like these belong to the field of developmental psychology, pioneered by Swiss psychologist Jean Piaget (1896-1980). In the years immediately following WWI, Piaget was teaching at a school in Paris. There, he became involved in scoring some of the first intelligence tests, and noticed that children tended to provide similar reasoning for their wrong answers. Intrigued by this, Piaget eventually moved back to Switzerland and studied how intelligence develops in children.

Developmental psychology is the study of how we change over our lifespans. Physical, intellectual, and emotional growth all contribute to psychological development. Physical changes during prenatal development, like exposure to alcohol, can have long-lasting cognitive consequences; not being able to feel love from parents and form attachments can result in social impairments. We'll look at studies designed to investigate these kinds of relationships, as well as at several theories of developmental stages proposed by Piaget and by other psychologists Erik Erikson and Lawrence Kohlberg. Piaget focused mainly on cognitive changes; Erikson on changes in motivations; and Kohlberg on changes in moral thinking.

Developmental psychologists also seek to identify continuities in development, or things that stay the same from childhood to adulthood. This can help us understand all sorts of psychological processes more completely, from visual perception to language use. As an example, let's take a look at a study by psychologists at Imperial College London in 2010. Using an fMRI machine, they scanned the 'resting state' networks in the brains of 70 babies. They found that resting-state networks, which are parts of the brain that remain active even when we're sleeping, were developed to an adult level by the time babies reach a normal-term birth. Scientists had previously thought that one of these networks played a key role in introspection and daydreaming.

The results of the London study mean that either that newborn babies are capable of daydreaming, which was previously thought not to be true, or that the previous theory about which network regulates daydreaming is incorrect. Studying babies gave the psychologists new insights into introspection and daydreaming, processes more commonly associated with adults. Developmental psychology does not just study infants and children in a vacuum--it tries to connect these stages with a more complete understanding of what it means to be human.

Ultimately, as in many areas of psychology, the fundamental question of nature vs. nurture underlies many of the studies and theories in developmental psychology. Developmental stages like Piaget's and Erikson's seem to have some innate components; they happen at around the same ages in most people and are often tied to physical changes. And yet parenting certainly has an effect on children's ability to move swiftly and easily through these stages; children who are neglected or abused often fail to develop normally.

Psychological growth is related both to biology and to social interaction. Developmental psychologists try to tease these factors apart by theorizing the changes in developmental stages while also identifying the continuities from childhood to adulthood.