Child Development From Infancy to Adolescence. Laura E. Levine
above. In these theories, each stage has characteristics that distinguish it from the stages that come before and after. Other theories, however, describe processes that change development in small increments.
Figure 1.1 Quantitative change and qualitative change.
One way to describe these two views of development is that continuous development represents quantitative change and discontinuous change represents qualitative change. Quantitative changes are changes in the amount or quantity of what you are measuring. For instance, as children grow they get taller (they add inches to their height), they learn more new words (the size of their vocabulary increases), and they acquire more factual knowledge (the amount of information in their knowledge base grows). However, some aspects of development are not just the accumulation of more inches or words. Instead, they are qualitative changes that alter the overall quality of a process or function, and the result is something altogether different. Walking is qualitatively different from crawling, and thinking about abstract concepts such as justice or fairness is qualitatively different from knowing something more concrete, such as the capitals of all 50 states. Typically, stage theories describe development in terms of qualitative or discontinuous change, while incremental theories describe development as occurring through quantitative or continuous changes. These two types of theories may look at the same aspect of development but describe the way it happens very differently. Both types of theories are described in Chapter 2.
Quantitative changes: Changes in the amount or quantity of what you are measuring.
Qualitative changes: Changes in the overall nature of what you are examining.
Stage theories: Theories of development in which each stage in life is seen as qualitatively different from the ones that come before and after.
Incremental theories: Theories in which development is a result of continuous quantitative changes.
Stability Versus Change
How much do we change during the process of development? As we grow, develop, and mature, are we basically the same people we were at earlier ages, or do we reinvent ourselves along the way? We find evidence of both stability and change as we look at development. For instance, characteristics such as anxiety, depression (Lubke et al., 2016; Nivard et al., 2015), shyness (Karevold, Ystrom, Coplan, Sanson, & Mathiesen, 2012), and aggressiveness (Dennissen, Asendorpf, & van Aken, 2008) tend to be relatively stable over time. However, what does change is the specific way in which these characteristics are expressed. For example, young children hit, kick, or throw things when they are angry, but school-age children are more likely to express their aggression through teasing, taunting, and name-calling (Liu, Lewis, & Evans, 2013), and adolescents attack each other through social means (for example, spreading rumors or excluding others from social activities; Wang, Iannotti, & Luk, 2012).
As another example of stability and change in development, we know that self-esteem goes through predictable changes as children move through childhood and adolescence. As you will learn in Chapter 10, young children often have a very high opinion of themselves and their abilities, but this high self-esteem typically drops as they enter school, and their appraisal of their own abilities becomes more realistic. Early adolescence often brings another downturn, but self-esteem then rises steadily through the remainder of adolescence. If we focus on these age-related changes in self-esteem, we see considerable change. If, however, we shift our focus to the individual, we find that children, adolescents, and adults often maintain their relative position on many of the personality characteristics we measure. From this perspective, we see considerable stability in self-esteem because children who score near the top on a childhood measure of self-esteem tend to become adolescents and later adults who will continue to score high on other measures of self-esteem (Trzesniewski, Donnellan, & Robins, 2013). Figure 1.2 illustrates how there can be both change and stability in a single characteristic.
Figure 1.2 Stability and change in self-esteem.
Individual Differences
Scientific research strives to identify general principles that describe average or typical patterns. We want to be able to make general statements about what usually happens. But you cannot spend much time observing children or adolescents without recognizing how different each one is from all the others. Our study of children needs to deal with both aspects of development—those aspects that are universal and shared by all or almost all members of a particular group, and those in which we differ from each other.
Throughout this book you will learn about general conclusions that are drawn from research. Although these are true as general statements, there also are numerous exceptions that give us insights we would not have otherwise. For example, children who grow up in poverty are at risk for a number of developmental and mental health problems, but some of these children manage to thrive in the face of great difficulty. In Chapter 13 we look at the factors that promote resilience in the face of a wide range of developmental risks and contribute to these individual differences.
While we can make a number of valid general statements about how development proceeds, the developmental pathway of any given individual is difficult to predict. Different pathways can result in the same outcome, a process known as equifinality (equi = equal, finality = ends). For example, depression may result from biological and genetic processes, but it also can result from early traumatic experiences. However, it is also true that the same pathway can lead to different outcomes, known as multifinality (Cicchetti & Toth, 2009). For example, children who are victims of abuse can have many different long-term outcomes that can include depression but also resilience and healing. Individual characteristics of a child or an adolescent, including the child’s temperament, sociability, and physical and intellectual ability are just some of the characteristics that may influence the specific outcome in any given situation.
Equifinality: The principle by which different developmental pathways may result in the same outcome.
Multifinality: The principle by which the same pathway may lead to different developmental outcomes.
Individual differences. Characteristics of individual children, such as age, gender, or ethnic background, can affect the developmental process, so outcomes that apply to one child will not necessarily apply to another. This means we must always be mindful of individual differences when we reach our conclusions.
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Although we routinely pay attention to how personal characteristics such as gender, race, ethnicity, age, socioeconomic status and others impact an individual’s development trajectory, the concept of intersectionality reminds us that these characteristics do not exist in isolation, but rather intersect with each other in complex ways that create unique developmental trajectories. Being a Black woman is a different experience from being a Black man, and being a Black woman is different from being a White woman. Both of