8 Developmental Psychology

Susan Abel; Samantha Brown; and Tanya Machin

Introduction

This chapter was originally written by Kuhlmeier et al., (2019) for the Canadian version of this handbook. We’ve updated the chapter to ensure the information reflects the Australian context and is therefore relevant to psychology students in Australia. The chapter introduces you to developmental psychology and associated careers. You can also listen to three people talk about using their knowledge of this field in their work as a guidance counsellor, paediatric psychologist, and case manager.

What Is Developmental Psychology?

As a human progresses through life, they transition from a zygote to a crying infant, from a babbling toddler to a curious preschooler, from a quick-learning primary school student to a broody adolescent, from an independence-seeking emerging adult, to a mature, and then at last, a senior adult. Across the lifespan, there are numerous physical, cognitive, and social changes. The field of developmental psychology is focused on observing these changes and elucidating their underlying mechanisms.

People with training in developmental psychology have learned how to be scientists. Like all scientists, they know the key theories of their field, and importantly, they recognise how those theories came to be. They can create empirical research methodologies to test new hypotheses, and they analyse the resulting data. They know how to critically evaluate claims and effectively communicate findings to other scientists, as well as the broader community. Depending on their chosen career and level of education, people trained in developmental psychology may apply some or all of these skills in their work.

The specific area of interest for a psychologist or psychological scientist interested in developmental issues may differ greatly from the interests of other psychologists or scientists. It’s arguably the most interdisciplinary of the traditional areas of psychology, as individuals may focus on development in relation to sensation and perception, cognition, reasoning and behaving in the social environment, personality, and brain systems. Within these topics, psychologists and scientists may focus on what we think of as normative development, as well as atypical development.

Because of this diversity, the questions psychologists and scientists interested in development can ask may seem disconnected from each other. Take a look at a typical introductory textbook on developmental psychology and you will likely see research questions as wide-ranging as: When do infants perceive physical depth? How do children learn the meanings of words? How does moral reasoning change from early to later childhood? Is the development of theory of mind in humans different from that of other species? How do bullying experiences in childhood affect later victimisation experiences in adulthood? How do cultures differ in pedagogical practices? What is the role of parents in the development of emotion regulation? How does gender identity develop?

The thread that connects these diverse topics, though, is the approach that people interested in developmental psychology take. There is a shared interest in understanding the mechanisms of change by examining the interactions between nature (our genetic inheritance) and nurture (the physical and social environment). Within this framework, species-typical developmental paths can be observed, but intriguing individual differences may also be uncovered.

Perhaps one of the best ways to picture the general context of development is by considering Urie Bronfenbrenner’s seminal Bioecological Model (Bronfenbrenner, 1979) shown in Figure 8.1. This model considers the multi-directional impact of environmental factors on a child’s physical, social, emotional, and cognitive development. In the model, there are a series of nested systems, with the child (including his or her particular combination of genes, temperament, age, health, and physical appearance) at the center. The systems interconnect, and themselves exist within the ‘chronosystem’, which considers circumstances that change over time.

A visualisation of Bronfenbrenner's bioecological model
Figure 8.1: Bronfenbrenner’s Bioecological Model Considers the Child’s Environment as a Nested Series of Interconnected Systems. [Source: Visual adaptation of Bronfenbrenner’s bioecological model of child development (Bronfenbrenner, 1979), adapted from Jacqueline. Used under a CC-BY-SA licence. Note: SES = socioeconomic status.]

When you consider this complexity, as well as the various domains of development that psychologists and psychological scientists examine, it may not be surprising that the methods used are quite varied. Some methods share commonalities with other areas of psychology: surveys, naturalistic or structured behaviour observation, verbal interviews, genetic assays, and neuroimaging with functional magnetic resonance imaging and electroencephalography, among others. A primary consideration within developmental research, though, is the age-appropriateness of the methods. This is particularly evident when testing infants who are not yet speaking and have limited motor ability, but applies to people of all ages, including older adults.

Another consideration is how development is to be examined. For example, does the research question pertain to whether an ability is present at a certain age? If so, psychological scientists might focus on one time point (e.g., five months of age). Alternatively, is a comparison to be made between certain ages? In this case, scientists may use a cross-sectional approach, comparing different groups of children of different ages, or they might create a longitudinal design in which they follow the same children over a period of months or years. Yet another approach is the microgenetic design, in which scientists attempt to gain an in-depth understanding of the mechanisms of change. In a microgenetic design such as Westlund et al., (2016), the focus is on children who are thought to be on the cusp of a particular change, and the researchers make observations during a number of sessions over a short period of time.

Section Recap

People trained in developmental psychology have learned the historic and current theories of developmental science and have a critical understanding of how to conduct and interpret research. One individual’s specific focus may differ greatly from another’s (e.g., the development of numerical understanding versus gender development), but they will share a common interest in uncovering the mechanisms of change. In turn, these mechanisms are considered within the complex interactions between nature and nurture.

The last section of this chapter presents some of the many careers and educational paths related to developmental psychology. Before getting there, though, you’ll see examples of research and how it continues to be extended and applied. These sections are divided into two areas of developmental research: social and cognitive. The lines separating these areas may seem ‘fuzzy’ at times – for example, a researcher interested in the development of a cognitive process will likely consider the role of the child’s social experience (e.g., how is information being presented to the child by others?). Yet, the divisions provide an organisational scheme for presenting important themes and research methods within the larger field of developmental psychology.

Social Development

The earliest social experiences for humans occur soon after birth, often with the immediate family. In typical development, for example, newborns show a marked attention to faces and soon can recognise the individual faces of those around them (e.g., Bartrip et al., 2001). This early interest in people is thought to start us on a developmental path toward the complex sociality that characterises our species.

This section will begin by considering what psychologists and psychological scientists have discovered about social experiences during infancy and early childhood. Focus will then turn to the development of social relationships, including the child’s own social identity. Throughout, examples will be presented of how this knowledge has been extended and applied. The topics and examples are, of course, limited, but the aim is to present major themes and directions.

photo of a young infant looking at a caregiver’s face
Figure 8.2: Young Infant Looking at a Caregiver’s Face. By Marcin Jowiak. Used  under an Unsplash licence.

Early Social Experiences

Our species has a relatively long period of vulnerability – we are born helpless and unable to survive without a caregiver. To ensure infants’ survival, and by extension, the survival of the species, infants and caretakers have developed a complex system of behaviours that fosters a strong relationship and motivates adequate caregiving (Simpson & Belsky, 2008), illustrated here in Figure 8.2.

It was relatively recently, though, that we started to have a more complete understanding of the necessary features of human caregiving. Observations of children who were separated from their parents during World War II showed that these children were emotionally disturbed – even those who were in institutions that provided good physical care (e.g., Bowlby, 1953). What appeared to be missing, it was argued, was the opportunity to create socio-emotional bonds with caregivers. Relatedly, research by Harry Harlow in the 1950s demonstrated that infant rhesus macaque monkeys preferred to spend time in contact with a cloth-covered apparatus than a metal wire apparatus, even though the latter provided milk. In fact, the infant monkeys with access to a ‘cloth mother’ showed more species-typical behaviour, exploring the world and then returning to the soft apparatus as if it were a secure base.

Together, these findings formed the initial basis of Mary Ainsworth and John Bowlby’s attachment theory. The ideas were expanded through studies suggesting that infants’ early experiences with primary caregivers shape their social and emotional development. Through the interactions with a sensitive caregiver, infants form a ‘working model of attachment’, a mental representation or schema of positive social relationships. Without these early experiences – or with experience with an insensitive caregiver – children’s social development can be compromised (see the text box Case Study: Romanian Adoption Studies below for more on this topic).

Since this initial research, psychological scientists have continued to expand our understanding of the significance of early social experiences. For example, there is evidence for both cultural universals and cultural variations – though the importance of attachment security appears to be universal, securely attached children in different cultures may differ in how often they’re in close physical proximity to their mothers (e.g., Posada et al., 2013). Additionally, the research in this area has provided us with a foundation for creating interventions to improve parent-child interactions. Psychologists who specialise in developmental issues may work with clinical psychologists and other healthcare professionals to design and evaluate programs that focus on sensitive parenting behaviour. As one example, Professor Matt Sanders and colleagues from the Parenting and Family Support Centre at the University of Queensland in Australia developed the Triple P – Positive Parenting Program® to enhance parents’ knowledge, skills, and confidence in managing family issues (Sanders, 2008). Meta-analysis has found the program can enhance parents’ wellbeing and satisfaction as well as child social, emotional, and behavioral outcomes (Nowak & Heinrichs, 2008; Sanders et al., 2014).

Psychologists have further applied the research undertaken by psychological scientists on early social experiences to questions about the impact of non-parental childcare. For many families, parents hold jobs by necessity or choice, and children may spend time with other caregivers. Studies suggest that when childcare is high quality (e.g., low turnover of caregivers and a small number of children per caregiver), children can still form secure attachments with their mothers when their mothers show sensitivity in their time together. Further, high-quality childcare can reduce disadvantage for vulnerable children living in families where caregivers receive limited personal or professional support in their parenting roles (Moore et al., 2012; Moore & McDonald, 2013).

Case Study: Romanian Adoption Studies

As you have just read, throughout the 1900s, developmental psychologists increased our understanding of the role of sensitive caregiving in early social development. It may come as a surprise, then, to learn that as late as the 1980s and 1990s, many children in Romania lived in institutions with relatively little contact with caregivers, as demanded by the political dictatorship at the time.

When the political power shifted, children were adopted by families in different countries. Across a series of studies, the development of these children was examined, often in comparison with both Romanian and non-Romanian children who had been adopted early in infancy (e.g., Nelson et al., 2007; Rutter et al., 2004). The studies found that Romanian children who were adopted at an older age (e.g., 12 to 24 months and 24 to 42 months) often showed atypical physical, social, and cognitive development as compared to children who had been adopted at a younger age, even after years of living in a loving and supportive environment.

These findings were important for the information they provided on the significance of early social experiences in human development and for the implications for public policy (Rutter et al., 2009). Also notable, though, were the research ethics considerations, such as the potential for exploitation, the risk/benefit ratio, and cultural sensitivity (Zeanah et al., 2006).

Development of The Self

It may seem strange to read about the development of ‘the self’ in a section on social development. Yet one’s self-concept develops through interactions among all the systems in Bronfenbrenner’s model (Figure 8.1), including, importantly, our interactions with others. Early in development, an emerging sense of self can be seen when infants recognise that they have agency and are able to control their environment (to some extent!). For example, at two to four months of age, infants show excitement when they can cause a mobile to move via a string attached to their kicking foot (e.g., Rovee-Collier, 1999). In the toddler years, children come to realise when looking in the mirror that they’re looking at an image of themselves. The sense of self continues to become more elaborate during the preschool years – three- to four-year-olds will describe themselves in terms of their physical features (‘I have brown hair’) as well as their social relationships (‘I have a brother’). During the primary school years, children increasingly engage in social comparison (‘Other kids at school do better in math’, e.g., Harter, 1999), and in adolescence, the importance of social acceptance by peers is strong (e.g., Damon & Hart, 1988).

Researchers and psychologists have now amassed a rich body of research on the development of the self, including focus on topics such as ethnic, sexual, and gender identity. In many cases, the research aims to be cross-cultural, as identity formation is influenced by the opportunities children and adolescents have, which in turn are impacted by economic, historical, and individual factors. While attitudes and expectations about gender identity and roles have become less stereotypical in western cultures in the recent past, the research is continually being applied to improve health and wellbeing (see the Gender Development in Transgender Youth text box below for an example in relation to gender identity).

Focus has also turned to one particular element of self concept: self-esteem. How we evaluate ourselves is related to life satisfaction. Low self-esteem in childhood and adolescence is associated with negative outcomes such as substance abuse, depression, and withdrawal from social interactions (e.g., Donnellan et al., 2005). Receiving praise can typically help to increase self-esteem. However, researchers have suggested that inflated praise (‘You are the best at drawing!’) can have detrimental effects on children with low self-esteem. In one study, children visiting a museum drew a picture and were told that it would be evaluated by a painter (there was no actual painter, only the experimenters). Some children received inflated praise (‘You made an incredibly beautiful drawing!’), while others received no praise or non-inflated praise. Children with low self-esteem who received inflated praise were less likely to take on a new challenge than other children, suggesting the inflated praise backfired – perhaps because it set high standards these children did not feel they could meet (Brummelman et al.,  2014). Discussion of this research has been valuable in educational settings as praise concerning participation rather than achievement has become more common.

Gender Development in Transgender Youth

Gender identity is typically defined as an individual’s awareness of themself as male, female, or non-binary (e.g., non-binary, gender fluid, agender). A person’s gender identity may not align with the sex assigned to them at birth, or their primary or secondary sex characteristics (American Psychological Association, 2015). Recent population-based estimates suggest around 1 per cent of Australians identify as transgender (Pang, nd).  Some First Nations Australians also use terms such as ‘brotherboy’ and ‘sistergirl’ to describe trans and gender diverse people in their community. Gender identity is therefore different to sexual orientation, which is conceptualised in two parts. The first is a person’s sense of the degree to which they feel sexually and/or emotionally attracted to other people (e.g., sexual, demisexual, asexual). Secondly, orientation refers to the direction of the attraction. An individual may be attracted to a person whose gender is the same and/or different to their own, or to people who have another gender identity (e.g.,  gender neutral or fluid). Some people also consider their attraction is not based on gender.

The TransYouth Project, led by developmental psychologist Dr Kristina Olson, examines transgender children’s gender development. At the time of writing, it’s an ongoing longitudinal study of transgender children from North America (ages 3 to 12 years at the start of the study), though some early findings have been published (for a summary, see Olson & Gülgöz, 2018). These children have socially transitioned (e.g., they are referred to by a pronoun not traditionally used for their natal sex) and thus have significant parental support of their gender identities. Because of this, the researchers are cautious in generalising the findings beyond similar samples.

The TransYouth Project is the first of its kind, researching gender development in transgender youth using quantitative empirical methodologies. The research thus far has examined the continuity and discontinuity of gender identity, researcher biases in assessing gender, and the implications of social support and transitioning on wellbeing in transgender and gender diverse youth. One finding thus far is that socially transitioned children’s gender development is quite similar to gender-typical peers and gender-typical siblings. Future research directions include larger and more diverse samples with children who have and have not socially transitioned.

Peer Relationships

Psychologists and psychological scientists have long claimed that relationships with peers are integral to children’s development. The interactions with similarly-aged ‘equals’ often allows the free exchange of ideas and criticisms, which can lead to the development of new concepts about how the world works. Cooperation with peers helps children develop social and emotional skills valued in the culture.

four children in a room with one child excluded
Figure 8.4: Young Girl Being Socially Excluded and Rejected by Peers. By RODNAE Productions. Used under a CC0 licence.

Among the different types of peer relationships, the study of friendship – and how the concept of ‘friend’ changes during development – has provided a large body of research. Having close, reciprocated friendships as a child is linked with positive outcomes even into young adulthood (e.g., Bagwell et al., 1998). That said, friendships with individuals who promote dangerous or unhealthy behaviours can be costly (e.g., Simpkins et al., 2008).

Peer relationships can include aggression, harassment, and violence, in person or online (i.e., cyberbullying) for some children and adolescents. The consequences of being bullied (Figure 8.4) are broad and include academic difficulties, stress-related illness, loneliness, biological changes within the brain, and suicide. By some accounts, 25 per cent of students in Australia experience bullying at school (Price Waterhouse Coopers, 2018). Further, children who are more likely to be bullied are in vulnerable populations such as children who identify as non-cis gendered, LGBTQI+, have a disability, are culturally or linguistically diverse, or are First Nations Australians.

screenshot of home page of Bullying No Way! website
Figure 8.5: Bullying. No Way! By State of Queensland. Used under a CC-BY-NC licence.

Researchers and psychologists have been working with organisations to connect science to practice and practice to science, in turn creating and evaluating programs that promote positive relationships. For example, the National Centre Against Bullying is an advocacy body comprising psychologists, educators, and industry experts. The group works to provide evidence-based information and advice to school communities, parents, children, and government bodies about bullying, the economic and social impact, and strategies to mitigate against bullying. They also host conferences to allow other researchers in the field to share their work with each other such as the Safe and Supportive School Communities Working Group (comprising representatives from all education jurisdictions in Australia). Supported by the Queensland Department of Education, the Safe and Supportive School Communities Working Group created the Bullying. No Way! (Figure 8.5) project that aims to provide schools, parents, and children with evidence-based resources. Research has found students are more confident in their ability to intervene in a bullying event in the playground after completing the Bullying No Way! program (McWilliam et al., 2016).

Emotional Regulation

In developmental psychology, the study of emotions occurs at many levels: neural responses, physiological responses such as heart rate, the subjective feelings associated with emotions, the recognition of others’ emotions, and the cognitive processes that can influence these distinct levels (e.g., Siegler et al., 2018).

Here, we highlight one aspect of emotional development: the ability to regulate one’s emotions. Though we have situated this discussion within the social development section of this chapter, the topic actually bridges social and cognitive development. Regulating emotions can entail cognitive processes, including inhibitory control, reassessment of goals, and creation of new  behavioural strategies. But emotion regulation can also occur in a more social context, such as the co-regulation that can occur with parents or peers.

Emotion regulation plays a significant role in wellbeing, with implications for anxiety and depression. Researchers in both developmental and clinical psychology often work together to apply research findings in the creation of interventions. One example is the use of video games that allow children with moderate to elevated levels of anxiety to practice controlling their stress. The game MindLight, created by developmentalist Dr Isabella Granic, along with a team of researchers and game designers, lets children virtually explore a dark mansion with a light that becomes brighter as they relax. Because the game is fun and engaging, children get repeated experience controlling their own anxious emotions as they play. Evaluating the effectiveness of the game is ongoing, and comparisons are being made to existing interventions including traditional cognitive behavioural therapy (e.g., Schoneveld et al., 2016; Wols et al., 2018).

Section Recap

This section has provided a brief summary of social development, with emphasis on early interactions with caregivers, the development of a sense of self, and peer relationships. In each case, examples of how research findings have been applied — in various contexts (e.g., education, parenting) and with various goals (e.g., public policy) — have been presented.

Underlying our social interactions, though, are cognitive processes that support our interpretation of others’ behaviour and guide our decision-making. In the next section, we’ll provide an overview of some major research areas of cognitive developmental psychology and give examples of applications of the work.

Cognitive Development

In a general sense, psychological scientists who specialise in cognitive aspects of development study how our abilities to acquire, store, and process information develop. A more specific definition of ‘cognition’, though, is the ‘mental processes and activities used in perceiving, remembering, thinking, and understanding, and the act of using these processes’ (Ashcraft & Klein, 2010, p. 9). Cognitive processes, therefore, are internal, occurring inside the brain. Because of this, cognition is typically inferred from behavioural or neural measures during carefully designed experiments.

This section will provide examples of research on cognitive development, noting how the findings can apply to other areas of the field of psychology, as well as other disciplines and non-academic communities. That said, many psychologists may conduct ‘basic science’, remaining agnostic about any application to, for example, health or education. Indeed, the basic science underlying any effective application or intervention will take many years to complete, and the potential applications may only be realised after a large body of findings have been amassed and interpreted. Knowing this, it’s important to approach the claims that specific toys or videos will make children ‘smarter’ with dose of healthy scepticism (e.g., Schellenberg & Hallam, 2005).

Perception and Early Cognitive Development

Decades of research with humans and non-human animals have led to the conclusion that the wiring of a species-typical brain is, in part, a result of experiences within a species-typical environment (e.g., voices, movement, three-dimensional objects). The brain is thus thought to ‘expect’ certain input from the environment to fine-tune itself by strengthening or pruning synapses. This experience-expectant plasticity has benefits (other areas may be able to take over when localised damage occurs), but it also has costs. If the ‘expected’ environmental information is not there, then development can be compromised.

Findings from infants who are born with cataracts that obscure vision demonstrate a cost of experience-expectant plasticity. Researchers have found that children who have cataracts medically removed later in development have greater visual impairment than those who have them removed earlier (see Maurer, 2017). Research such as this has led to modern practices of early removal of cataracts when surgery is possible, with the aim of providing the infant visual system with the experiences that are important for development.

But how do we even know what infants see when they can’t verbally communicate to us about their perceptions? Though there are many methodologies that capitalise on different infant behaviours such as reaching or sucking, there has been a long history of measuring infants’ looking behaviour. Experimental procedures using a habituation/dishabituation design, for example, capitalise on infants’ initial interest in new things, as well as their waning interest over time. In a typical set-up, a visual stimulus (e.g., a striped object) is placed in front of an infant repeatedly. For the first few minutes, infants spend much of the time looking at the stimulus, but over time, they habituate to the stimulus and begin to look elsewhere more and more. When this looking-away behaviour reaches pre-determined criteria, a new stimulus is presented (e.g., a differently patterned object). Increased looking to this new stimulus is called dishabituation and suggests that an infant can differentiate between the two stimuli. Using this type of methodology, psychological scientists have been able to examine early perception and cognition in relation to objects (e.g., infants’ early sense of number, discussed in the text box Number and Mathematics) and people.

A common methodology that is used to examine infant auditory discrimination is known as the conditioned head turn procedure. At the start, infants are trained that when a change in an ongoing sound occurs, a fun toy appears to their side. When they learn this association, they readily turn their head in the direction of the upcoming toy if they hear the change. Using this procedure, developmental psychologists have examined how infants discriminate among different speech sounds. For example, six-month-old infants growing up in monolingual English-speaking households in Sydney would turn their head when a speech sound common in English changed to a speech sound common in Thai. Intriguingly, nine-month-olds with no experience with Thai found it more difficult to differentiate these sounds than the six-month-old infants (e.g., Mattock & Burnham, 2006). Thus, there appears to be a time in early development in which our auditory perception allows for this discrimination, but with increased exposure to the predominant language in our environment, we narrow our perception. Although this may seem detrimental – and perhaps the opposite of how we usually think about development – the narrowing and focus may underlie the attainment of expertise.

Number and Mathematics

imagins showing blue and yellow dots on a gray background
Figure 7: Without Counting, Can You Tell if there are More Yellow or More Blue Dots? Humans and other animals can discriminate between numerosities – like the yellow and blue dots here — using a non-symbolic, approximate sense of quantity.

What does cognitive developmental neuroscience have to do with mathematics education? A lot, actually. Many developmental psychologists have been focusing their research on how children learn about numbers using both behavioural and brain-imaging methods.

Young infants (and many non-human animals) can notice the difference between an array of, say, eight dots and an array of four dots. We can estimate numerical magnitude and discriminate between magnitudes, even at a young age. To try an adult version of this task in which both arrays are presented together, quickly look at Figure 7 without explicitly counting the dots. Are there more yellow or blue dots?

Of interest to many researchers is the role these early representations play in the acquisition of symbolic numbers, such as Arabic numerals and number words (e.g., Feigenson et al., 2013; Sokolowski et al., 2017; Xenidou-Dervou et al., 2007). Does, for example, the development of basic magnitude processing impact the development of arithmetic skills? If so, what might this mean for mathematics education?

Researchers and psychologists are also examining children who have severe difficulties with arithmetic, called developmental dyscalculia (DD). For example, Dr Daniel Ansari uses behavioural and functional neuroimaging methods to study the causes and neural correlates of developmental dyscalculia (e.g., Bugden & Ansari, 2016). By partnering with psychologists who are interested in the educational field, he aims to apply research findings to the classroom. Dr Daniel Ansari explains dyscalculia in Video 8.1 below.

Video 8.1: Understanding Dyscalculia: Symptoms Explained

Language Development

Psychological scientists have a long history of studying language development, considering important aspects such as the perception and discrimination of speech sounds and the ways in which children learn the meanings of words. Related research focuses on how children learn to read. The area is broad, and entire university courses can be designed to introduce the topic. Here, we’ll focus specifically on the role of adults in children’s language learning and critical periods within development.

Counterintuitively, adults don’t actively teach language as much as you may think. Parents, for example, don’t often explicitly teach grammatical rules. Instead, much of the learning comes from exposure to language. Parents will use infant-directed speech (higher pitch, with exaggerated intonation) when talking to an infant, and the speech emphasises words for objects in the environment. During these ‘conversations’ children will also pay attention to the speaker’s focus of attention (via eye gaze, pointing, etc.) and use these pragmatic cues to determine what object the speaker is likely labeling.

Imagine, however, if a child doesn’t have any exposure to language. Fortunately, such a situation is rare, but there are documented cases of abused children who were not exposed to language with any consistency. Children who were rescued from abuse later in development didn’t successfully learn language, even after living in a social and loving household. Similar findings also come from situations in which there was no abuse, yet children were not diagnosed with deafness and, thus, there was no exposure to sign language until later childhood. There appears to be a critical period in the first four to five years of life where exposure to language is integral to language development.

The study of bilingual children and adults further supports the importance of a critical period. Adults who were exposed to a second language during their first three years of life show brain activation patterns to the second language that are like the patterns in monolingual adults who are listening to their native language. Those who learn a second language later, however, show different patterns (e.g., Weber-Fox & Neville, 1996).

But how do children manage to learn two languages at once? A classic, but now unsupported view was that learning more than one language would negatively impact learning more generally. While it’s the case that children learning two languages may learn each more slowly than children exposed to only one, the developmental ‘lag’ quickly disappears with age. These findings are important to policies around bilingual education, suggesting that immersion programs will not hinder learning (e.g., Holobow et a., 1991).

Understanding Others

Many topics already covered in this chapter relate to children’s developing understanding of the people around them. Attention to faces in early infancy, forming attachments to parents, and perceptual systems that parse the sounds of human language all support our ability to make sense of others’ behaviour and predict their future behaviour. In this section, we consider potential challenges to navigating the elaborate rules of social communication faced by people with developmental disabilities such as autism spectrum disorder (ASD) (see the text box on Autism Spectrum Disorder below).

Key to our mature understanding of others is the human-unique suite of social cognitive skills that researchers refer to as theory of mind. Theory of mind is our understanding that the behaviour of other people is caused by their internal mental states, such as their intentions, desires, and beliefs. We can’t see others’ beliefs, but we can infer them based on the context, past behaviour, and current behaviour. You will likely predict, for example, that a friend will look for his book on his desk where he left it, even if you borrowed it when he was away and left it on your own desk. You know that his belief as to the location of the book is different from your own knowledge.

This type of inference undergoes a major change in the preschool years. Psychological scientists have found that many social, cognitive, and neurodevelopmental factors shape the timeline of theory of mind development. Some studies, for example, use electroencephalography (EEG) – a procedure that measures electrical activity of the brain over time using electrodes placed on the scalp – to assess ways in which brain maturation might be specifically related to developments in preschoolers’ theory of mind (e.g., Sabbagh et al., 2009). Related research considers the role of neurotransmitter systems (e.g., dopamine) in shaping children’s social cognitive development (Lackner et al., 2012).

Our brains develop within our social and cultural environments, as you have likely recognised throughout this chapter. Thus, theory of mind research also considers how brain maturation interacts with relevant, everyday social experiences. For example, parents’ use of mental state talk with their young children is correlated with children’s later theory of mind development (e.g., Ruffman et al., 2002). It’s possible that mental state talk provides them with fact-based knowledge about mental states, and it might help children  start to take the perspective of others by using their own perspectives as a comparison.

As noted, the ability to reason about others’ mental states is integral to efficiently navigating our social world. There are, thus, direct applications of the study of theory of mind to the study of autism, but the applications can extend far more broadly. For example, those studying how children learn from others (social learning) consider how children differentiate knowledgeable from ignorant individuals (e.g., Poulin-Dubois & Brosseau-Liard, 2016), and researchers who are characterising the factors that encourage or discourage bullying and prosocial behaviour consider underlying social cognitive reasoning (e.g., Dunfield & Kuhlmeier, 2013). As a further example, clinical psychologists may work with psychological scientists to examine the role of theory of mind in the etiology, pathology, and phenomenology of depression in adolescents and adults (e.g., Zahavi et al., 2016).

Autism Spectrum Disorder (ASD)

Autism spectrum disorder (ASD) is a lifelong developmental condition found in approximately one in 100 Australians (Falkmer et al., 2019 ). While research suggests autism is four times as prevalent in boys as it is in  girls, other studies suggest the diagnosis rates for women with autism are significantly understated (Arnold et al. 2020; Brugha et al. 2016). More recent research suggests one reason cisgender girls are diagnosed later than boys or not at all is due to the use of gendered diagnostic tools oriented towards behaviours associated with males (Beeger et al., 2013; Frazier et al., 2014). Gender identity is highly relevant to ASD as research suggest transgender and gender diverse people are more likely to have ASD than cisgender people (Strang et al., 2018, Warrier et al., 2020).

Presenting differently in each person, ASD affects a person’s ability to communicate and interact with others. ASD can present challenges such as difficulties with social communication, sensory hyper (or hypo) reactivity, or restricted and repetitive behaviours. Some people with autism like neurodiversity advocate Ethan Lisi (see Video 8.2 below) challenge the widely held notion that autism is a disease that needs curing, and posit that autism is simply another way thinking and looking at the world. Organisations such as the neurodivergent-led I Can Network work to promote inclusive education and employment for autistic people, and provide a peer-based mentoring program that celebrates autistic strengths.

Co-diagnoses such as intellectual impairment, attention deficit and hyperactivity disorder (ADHD), and language or anxiety disorders can have an enormous impact on how well a person with ASD copes with everyday life and their ability to live independently, or to need ongoing support. Developmental psychologists work with clinical psychologists and medical doctors to develop early interventions and therapy programs for children who need them.

Video 8.2: What it’s Really Like to Have Autism

Section Recap

This chapter has thus far been divided into two areas of developmental research: social and cognitive.  As you likely noticed, the lines separating the areas are at times ‘fuzzy’, yet there has been a tradition in developmental psychology to loosely organise around these two areas. This is not to suggest that the work occurs in two separate silos. For example, even research on children’s developing understanding of objects – including their understanding about the number of objects – will also consider the social environment. Learning about objects relies on not only on children’s perceptual development and recognition of physical causality, but also on how they learn from knowledgeable others about an object’s function and name. Number cognition develops within cultural systems that have symbolic count words, artifacts such as calculators and the abacus, and mathematics notation.

Perhaps in part due to the breadth of developmental psychology as a field, there are many relevant career paths that incorporate its theory and methodology, either directly or indirectly. In the next section, we provide examples of these careers, as well as some of the educational pathways’ students can take.

Educational Paths and Careers

Most of the studies and the applications of research findings described in this chapter are the result of projects led by psychological scientists who have completed a doctorate (i.e., PhD) degree. The basic science underlying any novel application or intervention can take many years to complete (indeed, basic science is often completed with no application in mind). Along the way, though, the work is only possible through the combined work of many individuals with many diverse types of educational backgrounds and job experience.

Before discussing different educational and career paths relevant to developmental psychology, it’s important to consider a distinction that will often confuse students early in their undergraduate training: How do psychologists differ in their focus? More specifically, before reading this chapter, some students might have reasonably, though incorrectly, thought that only clinical psychologists consider and apply the findings of psychological research.

In Australia, educational and developmental psychologists (more on this title later in the chapter) use scientific evidence to investigate and examine the wellbeing of people across the lifespan. This means you can find endorsed educational and developmental psychologists in many different places including schools, disability services, or aged care. They can also work with psychological scientists to investigate specific developmental issues and produce interventions or treatments. Conversely, psychologists with general registration or endorsement in clinical psychology tend to emphasise the individual differences – particularly those relevant to psychological health and wellbeing.

Many psychologists who specialise in child development, such as Stacey Freebody (pictured in Figure 8.9 and interviewed in Video 8.3 ), are primarily practitioners who’ve undertaken specialised training and supervision to work with children and their families.

image of a woman
Figure 8.9: Stacey Freebody is a Senior Paediatric Psychologist. Image reproduced with permission.

Video 8.3: Interview With Stacey, a Senior Paediatric Psychologist

With this distinction in place, we can now consider the educational and career paths relevant to developmental psychology. As in most disciplines, the career opportunities will differ based on the level of education completed, so undergraduate training is presented separately from postgraduate training in this section. Also, like many disciplines, there are few ‘hard and fast rules’ – remember there are many routes possible to reach your goals.

Undergraduate Training

In Australia, undergraduate degrees in psychology are general and not specialised in a particular area like developmental psychology. Universities across Australia have courses in their undergraduate programs that cover human development in general (e.g., developmental psychology) and more advanced courses – typically in a postgraduate degree – that may provide a specific focus on developmental psychology.

Knowledge gained from developmental psychology courses provides good preparation for graduate training in psychology, social work, speech-language pathology, occupational therapy, teaching, law, and public policy, among others. Some students take developmental psychology courses to complement their undergraduate and graduate training in education, and even computer science (e.g., educational software development). Of course, some people may start their careers with a bachelor’s degree without undertaking postgraduate study – it’s never too early to start looking at job advertisements and reading the professional profiles of people who have a career that interests you!

Many students who have an undergraduate psychology degree often mistakenly think they can’t work in developmental psychology. However, there are some jobs you can do with only an undergraduate degree and an interest in developmental psychology, including:

For some people like Rebecca Smith (pictured in Figure 8.10 and interviewed in Video 8.4), even short exposure to developmental psychology in their undergraduate degree can be enough grounding to enable them to start their professional careers.

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Figure 8.10: Rebecca Smith Works as a Case Manager. Image reproduced with permission.
Video 8.4: Interview With Rebecca, a Case Manager

 

Postgraduate Training

There are two types of postgraduate training that may interest students interested in developmental psychology: registration as a psychologist, and/or becoming a psychological scientist who investigates developmental psychology questions.

Firstly, for students who want to become a registered psychologist with a specific endorsement there is a lengthy training pathway to follow. Firstly, you will need to complete an APAC-accredited undergraduate degree in psychology, before completing a fourth year (typically referred to as honours) and then applying for a postgraduate program such as the Master of Professional Psychology to become a psychologist with general registration. Other psychology postgraduate programs can lead to endorsement in approved areas of practice such as educational and developmental psychology. You can find more more details about all the endorsements and pathways on the Psychology Board website. It’s important to remember that in Australia, terms such as ‘psychologist’ or ‘educational and developmental psychologist’ are protected titles and only those people who have completed the specific educational pathways and have recognised endorsement may use this title. However, many people who work in the field of developmental psychology have other titles such as guidance counsellor.

One of the pathways for people who hold the educational and developmental psychology endorsement like Emily Coote (pictured in Figure 8.11 and interviewed in Video 8.5) is to become a guidance or school counsellor.

image of a woman
Figure 8.11: Emily Coote Works as a Guidance Counsellor. Image reproduced with permission.
Video 8.5: Interview With Emily, a Guidance Counsellor

A non-practice pathway for students of developmental psychology is to become a psychological scientist and earn a PhD. PhD recipients are considered experts in their field and have strong research, data analytic, and critical thinking skills that can be applied to many different settings. They might be involved in projects such as the Longitudinal Study of Australian Children which has been following the development of 10,000 children and families across Australia since 2004 to investigate questions about parenting, family relationships, childhood education, non-parental child care and health. Graduates might also work for government organisations such as the Australian Institute of Family Studies which seeks to improve understanding of the issues affecting Australian families. Becoming a psychological scientist who specialises in developmental psychology is also a good option for people with other types of undergraduate degrees who are interested in learning more about developmental issues. For example, a counsellor interested in understanding the impact of a specific issue on family life, or a teacher interested in the impact of technology on the academic development of primary school children. Of course, students of psychology may also want to investigate research into specific developmental issues, and are ideally placed to do so. For example, two of the authors of this chapter (Susan and Tanya) are not registered psychologists, but have completed undergraduate degrees in psychology before undertaking PhD and further research in developmental issues.

Many students often mistakenly think that only ‘smart’ people can complete a PhD. However, postgraduate research training is perfect for people who enjoy discovery and problem-solving. Perhaps an underemphasised trait, though, is having an entrepreneurial spirit that motivates you to create the career you want. Both those who are recognised as an endorsed educational and developmental psychologist as well as those who research developmental issues have successfully created careers within both the academic and nonacademic sectors, using their knowledge and skills in developmental psychology in many ways, including the following:

Research and teaching (typically with a PhD)

  • universities/government/specialised research centres

Applied/consulting (typically with a master’s degree or PhD)

  • software development or online content curation marketing
  • youth services or child welfare agencies
  • organisations supporting vulnerable populations such as people with ASD and LGBTQI+ people
  • education – curriculum and content education
  • science writing for organisations such as museums
  • toy design.

Conclusion 

People trained in developmental psychology are well-versed in the key theories of their field. They can create empirical research methodologies to test new hypotheses, and they analyse the resulting data. They know how to critically evaluate claims and effectively communicate findings to other scientists, as well as the broader community. In some cases, research findings become relevant to the development of innovative programs and interventions, which themselves must be evaluated empirically before implementation and policy change. Depending on their chosen career and level of education, people trained in developmental psychology may apply some or all these skills in their work.

This chapter has been adapted by Susan Abel, Samantha Brown, and Tanya Machin, School of Psychology and Counselling, University of Southern Queensland. It has been adapted from Kuhlmeier, V. A., Mayne, K., & Craig, W. (2019). Developmental Psychology. In M. E. Norris (Ed.), The Canadian Handbook for Careers in Psychological Science. Kingston, ON: eCampus Ontario. Licensed under CC BY NC 4.0. Retrieved from https://ecampusontario.pressbooks.pub/psychologycareers/chapter/developmental/

Send us your feedback: We would love to hear from you! Please send us your feedback.

Copyright note: Permission has been granted by Stacey Freebody, Rebecca Smith, and Emily Coote to use their photographs.

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Please reference this chapter as:

Abel, S., Brown, S., & Machin, T. (2022). Developmental psychology. In T. Machin, T. Machin, C. Jeffries & N. Hoare (Eds.), The Australian handbook for careers in psychological science. University of Southern Queensland. https://usq.pressbooks.pub/psychologycareers/chapter/developmental-psychology/.

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The Australian Handbook for Careers in Psychological Science by Susan Abel; Samantha Brown; and Tanya Machin is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License, except where otherwise noted.

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