Reading B

Although a few early pioneers of the study of human development, such as G. Stanley Hall, viewed all phases of the life span as worthy of study, the science of human development began to break into age-group specialty areas during the twentieth century. Some researchers focused on infant or child development, others specialised in adolescence, and still others formed the specialisation of gerontology, the study of the social, psychological, mental and biological aspects of ageing and old age. In the 1960s and 1970s, however, a true life span perspective on human development began to emerge. In an influential paper, noted developmentalist Paul Baltes (1939-2006) laid out the seven key assumptions of the life span perspective seen in the following list (Baltes, 1987; also see Baltes, Lindenberger, & Staudinger, 2006). These are important themes that you will see echoed throughout this book. They will also give you a good sense of the challenges facing re-searchers and practitioners who study human development from a life span perspective.

1. Development is a Lifelong Process

Today’s developmentalists appreciate that human development is not just ‘kid stuff’, we can change throughout the entire life span. They also believe that development in any period of life is best seen in the context of the whole life span. For instance, our understanding of adolescent career choices is bound to be richer if we concern ourselves with formative influences in childhood and the implications of such choices for adult careers and success.

2. Development is Multidirectional

To many pioneers of its study, development was a universal process leading in one direction – toward more ‘mature’ functioning. Today’s develop-mentalists recognise that different capacities show different patterns of change over time; for example, some intellectual skills decline faster than others in late adulthood, some don’t change much, and some even continue to improve (see Chapters 6 and 7). Different aspects of human functioning have different trajectories of change.

3. Development Involves Both Gain and Loss

As we have noted already, development is not just gain in childhood and loss in old age. Rather, gain and loss are intertwined during every phase of the life span. Baltes believed that gain inevitably brings with it loss of some kind, and loss brings gain – that gain and loss occur jointly. Examples? As infants gain com-mand of the sounds of the language they hear spoken, they lose their early ability to ‘babble’ sounds heard in other languages of the world (see Chapter 8); gaining a capacity for logical thought as a school-age child means losing some of the capacity for fanciful, imaginative thinking one had as a preschooler (see Chap-ter 5); and choosing to hone certain skills in one’s career can mean losing command of other skills (see Chapter 9).

4. Development is Multiply Influenced

Today’s developmental scientists share Urie Bronfen-brenner’s belief that human development is the product of many interacting causes – both inside and outside the person, both biological and environmental (see Chapter 3). It is the often-unpredictable outcome of ongoing interactions between a changing person and his or her changing world. Some influences are experienced by all humans at similar ages, others are common to people of a particular generation, and still others are unique to the individual.

5. Development is Characterised by Lifelong Plasticity

Plasticity refers to the capacity to change in response to both positive and negative experiences. Developmental scholars have long known that child development can be damaged by a deprived environment and optimised by an enriched one. It is now understood that this plasticity continues into later life – that the developmental process is not fixed but rather can be altered considerably depending on the individual’s experiences. As discussed in the chapter Application box, elderly adults can maintain, regain or even enhance some of their intellectual abilities and lessen their risk of dementia with the help of physical exercise and a mentally and socially active lifestyle, or training designed to improve specific cog-nitive skills (Hertzog, Kramer, Wilson, & Lindenberger, 2009; Park et al., 2014). Studies tell us such cognitive benefits are rooted in neuroplasticity, the remarkable ability of brain cells and structures to change in response to experience throughout the life span, as when the brain recovers from injury or benefits from stimulating learning experiences. It is now clear that physical exercise and mental stimulation can result in changes in neuro-chemistry, the formation of new connections among neurons, and, remarkably, new neurons in the hippocampus of the brain – an area involved in learning and memory – even in an ageing brain (see Chapter 4).

6. Development is Shaped by its Historical-Cultural Context

This theme was discussed in some depth in Section 1.1 and will be illustrated throughout the book. For now, consider the launching of the internet as an example of an historical change with implications for human develop-ment. When baby boomers grew up, there were no mobile phones or home computers, much less an internet. The internet came into being in the early 1980s, around the time that home computers were becoming common (see, for example, Cotten, McCullough & Adams, 2011). Facebook was launched in 2004, Twitter in 2006, Snapchat in 2011. Media are now a big part of the daily lives of children and teens (Calvert, 2015; Lenhart et al., 2015). How are these technologies affecting adolescent development?

According to one analysis (Valkenburg & Peter, 2009), early studies of the impact of the internet on adolescents suggested that it was isolating them and keeping them from dev-elopmentally important social experiences such as interacting with peers. More recent studies are revealing positive effects of time on the internet and digital media use. Why? In the 1990s, adolescent internet users were fewer in number and usually surfed the net or talked to strangers in chat rooms. Now, many more adolescents use the internet and digital media to network with their friends – mainly through Facebook and other social media sites if they are girls, and often through video game sites if they are boys (Lenhart et al., 2015). And now that teens are spending much of their online time interacting with friends, studies are showing more positive correlations between internet use and social adjustment and wellbeing (Reich, Subrah-manyam, & Espinoza, 2012; Valkenburg & Peter, 2009). For emerging adults who have gone away to study, for example, social networking sites can be a way to hold on to the social support offered by their high school friends (Manago et al., 2012).

However, the question of the effects of digi-tal media on adolescents is far from resolved. For example, Roy Pea and his colleagues (2012) found that heavy media use – especi-ally spending large amounts of time watching videos, engaging in online communication and using multiple media at once – was nega-tively associated with feeling good about one’s close relationships and social acceptance, whereas spending more time in face-to-face conversations was positively related to these aspects of social wellbeing. Then there are the negative effects of cyberbullying to consider. Cyberbullying, which has increased in recent years (Jones, Mitchell, & Finkelhor, 2013; and see Chapter 10), is linked to stress, depression and suicidal thoughts among its victims (Hamm et al., 2015; Kowalski et al., 2014). We still have much to learn about how human development is being affected by the internet and digital media.

7. Development Must Be Studied by Multiple Disciplines

Because human development is influenced by everything from biochemical reactions to historical events, it is impossible for one discipline to have all the answers. A full understanding of human development will come only when many disciplines, each with its own perspectives and tools of study, join forces. Not only psychologists but also bio-logists, neuroscientists, educators, historians, economists, sociologists, anthropologists and many others have something to contribute to our understanding of human development. Where we once talked of developmental psychology as a field of study, we now talk of developmental science.