EARLY ADULTHOOD

PHYSICAL DEVELOPMENT
Early adulthood is, for most people, the time of peak physical capacity. The body reaches full height by the late teens, and physical strength increases into the late 20s and early 30s (Whitbourne, 2001). Manual agility and coordination, and sensory capacities such as vision and hearing, are also at their peak. But change is imminent, even in these basic capacities. Some decline in the perception of high-pitched tones is found by the late 20s (Whitbourne, 2001), and manual dexterity begins to reduce in the mid 30s. In general, people in early adulthood feel robust and energetic, although it is not unusual to see fluctuations around deadlines and exam periods! On the other hand, people in this age group are also legally able to use damaging substances, such as alcohol and tobacco, and many can obtain access to illegal stimulants or narcotics. Young adults also have increasing responsibility for organizing their own eating habits and exercise regimes. Not surprisingly, the health status and prospects of young adults are dependent more than ever before on their own behavioural choices.

COGNITIVE DEVELOPMENT
By the end of adolescence, most people are capable of the levels of reasoning that we would expect for normal functioning in adult society. Although there are wide individual differences in attainment, most young adults are able to deal with cognitive tasks in a more abstract way than before, and to attain solutions to problems by comparing possible explanations. Does this mean that cognitive development has reached a plateau? Many investigators of adult cognition think not. Riegel’s theory of post formal thought Riegel (1975) proposed that adult experiences expose us to a new level of cognitive challenge – the discovery of dialectical (opposing) forces. In other words, we find that many aspects of our environment can manifest contradictory features. This is especially so in the human environment. For example, someone we love can be warm and generous at times, but on other occasions the same person can be self-centered and aloof. Are they generous or selfish, affectionate or remote? There are many other contexts in which we experience contradictory information about a person, group or organization, or we encounter strongly differing points of view on the same issue. There may be no absolute resolution of the conflicts. We simply have to integrate our understanding into a more complex picture. Life, we discover, is often ambiguous and complicated. Riegel argued that achieving the intellectual ability to deal with the contradictions that confront us in our everyday life requires progress to a fifth stage of reasoning – the stage of dialectical operations, now more commonly called post formal thought. Research into post formal reasoning indicates that development continues well into adulthood (Sinnott, 1998). Research participants are often presented with problems relating to complex topics (e.g. in science, education, religion, politics or personal relationships) and encouraged to provide and justify decisions. Their reasoning is coded and categorized into stages. [post formal reasoning a level of thought beyond Piaget’s period of formal operations, characterized by the understanding that there may be multiple perspectives on a problem and that solutions may be context-dependent].

EARLY ADULTHOOD

It makes sense to divide adulthood into three broad phases: early (from approximately 18 to 40 years of age), middle (41–65), and late (66+). Clearly, this is only a rough breakdown, and there are substantial differences within each phase, but it does serve as a preliminary framework for the study of the largest period of human development – our adult lives. By the time we reach early adulthood, we have spent a long time developing. Like the young frog hopping to a new pond, the young person setting up a first home is physically and mentally transformed from the infant first presented to his or her parents. Just as it is difficult to determine precisely when adolescence begins and ends, determining exactly when adulthood commences proves elusive. There are some rough formal markers, such as reaching a particular birthday, gaining the vote or becoming eligible to join the military services, but these markers vary across and within societies. Other criteria, such as gaining financial autonomy, getting married or establishing a home, are met by different people at widely differing ages, if at all. In fact, no single event in and of itself establishes an individual as ‘adult’ in all areas of his or her life. This is part of the challenge of studying adult development. Not only are the boundaries difficult to identify, but the experiences are widely varied too.

ADOLESCENCE

SOCIAL AND EMOTIONAL DEVELOPMENT
The adolescent’s social world is changing fast. The changes reflect the biological and cognitive developments summarized above, as well as new opportunities and the impact of other people’s expectations. Gender and sexual development During adolescence, gender becomes of much more central importance for most individuals. The biological changes discussed above make gender all the more salient – to the adolescent and to others. One consequence is that societies’ expectations about gender appropriate behaviour are brought home more powerfully than ever before. During childhood, cross-sex interests are tolerated to some extent in girls (although, as we have seen in chapter 9, this is less the case for boys). But in adolescence, parents and peers tend to provide stronger messages about acceptable and unacceptable behaviour – there is a narrowing of the gender ‘pathways’ as we move closer to our adult roles (figure 10.3; Archer, 1992). In some cultures, the sexes are increasingly segregated in adolescence, although n others (such as many Western societies) many adolescents are particularly keen to socialize with the opposite sex. In societies that do allow for mixed gender interactions in adolescence, a number of factors bear on young people’s sexual development. Increased hormonal levels are associated with heightened interest in sex in both boys and girls. For boys, this tends to lead to involvement in sexual activity (though much of this is solitary), while girls tend to be more influenced by social factors, such as parental attitudes and friends’ sexual behaviour (Crockett, Raffaelli & Moilanen, 2003; Katchadourian, 1990). Whatever the specific influences and motivations, the outcome is that a lot of adolescents have apparently experienced sexual relations. For example, in America, about two-thirds of 12th graders (16- to 17-year-olds) report having had sexual intercourse (Crockett et al., 2003) – although this figure may be somewhat inflated by peer pressure. The importance of peers There is no doubt that peers are ery important to adolescents. During this phase of the lifespan, people spend increasing amounts of time in the company of their peers (Brown & Klute, 2003; Collins & Laursen, 2000) and increasingly focus on peer relations as crucial to their sense of identity (Pugh & Hart, 1999). You are probably aware of strong popular assumptions about the effects of peers on adolescents. Peers are often regarded as a potentially harmful influence, leading impressionable teenagers into dangerous experimentation (e.g. with drugs and sex), dereliction of responsibilities (e.g. schoolwork) and hostility to adults and adult society. Peer values are often assumed to be the antithesis of parental values. But were these your own experiences? Certainly, friends’ behaviour does tend to be correlated with adolescents’ choices and actions in many areas (Durkin, 1995). But, correlation does not equal causation. In fact, we choose our friends – and adolescents tend to choose friends who have similar interests. If you are a smoker, you probably will not choose to hang out most of the time with the sports crowd. More generally, adolescents themselves report that, although they are subjected to peer pressures sometimes, they do not generally experience this as a major influence on their behaviour or as something that they find particularly difficult to handle (du Bois-Reymond & Ravesloot, 1994; Lightfoot, 1992). Furthermore, perceived peer influence tends to vary across different domains of life. It is quite strong with regard to appearance (e.g. hairstyle, clothing) and socializing (e.g. dating, finding out where it is cool to be seen), but peer pressure is less influential when it comes to moral values, antisocial behaviour and career decisions (Brown, 1999). And when they do try to exert influence, peers are not invariably aiming to promote bad habits: for example, peers often try actively to dissuade their friends from smoking (Paavola, Vartiainen & Puska, 2001). Rather than peers providing the antithesis of parental influences, research suggests that the relationship is more complex. In early adolescence, some patterns of adolescent behaviour (such as drug use) tend to show a greater association with parental than peer practices (Bush, Weinfurt & Iannotti, 1994). Parents are often the first models in terms of drug use (smoking, drinking and other substances) and often the first to offer the young person an opportunity to try (Bush et al., 1994; Engels et al., 1994). Older adolescents perceive peer influence in matters of drug use as greater than parental influence (Bush et al., 1994). But this perception may not take into account that, by this age, individuals tend to have already chosen their peers. Evidence suggests that an adolescent’s choice of peers is itself influenced by his parents (i.e. the parents encourage or discourage particular friendships) and that the impact of friends’ behaviour is moderated by parental guidance (Blanton, Gibbons, Gerrard et al., 1997; Mounts & Steinberg, 1995). So peers are important, but not omnipotent. The ‘peer pressure’ issue is not the only aspect of adolescent development about which there are strong folklore beliefs that are not actually borne out by the research evidence. These discrepancies remind us once again that ‘common sense’ does not always provide a reliable basis for psychological analysis.

Piaget challenged

Although most developmental psychologists would agree that adolescent thought reflects important advances beyond childhood, not all agree with Piagetians about the nature of the changes, and not all of the evidence is consistent with the theory. For example, large-scale studies have reported that only small proportions of adolescents perform sufficiently well to meet the criteria for formal operational reasoning (Neimark, 1975; Shayer, Kuchemann & Wylam, 1976). The comprehensiveness of Piagetian theory is in doubt if it fails to characterize a majority. Contemporary researchers agree with Piaget that cognitive development does proceed during the adolescent years, but they disagree with him about the patterns and processes entailed (Byrnes, 2003; Klaczinski, 2000). During this period, young people show improved abilities in several areas, including deductive and inductive inferences, objective thinking, mathematical operations and decision making (Byrnes, 2003). But the developmental evidence does not support the Piagetian assumption of domaingeneral transitions. For example, participants’ scores on different reasoning tests do not correlate highly during adolescence, and there are greater age differences on some tests than on others (Csapo, 1997). If a general improvement were underway, we would expect to find comparable and simultaneous improvements across cognitive domains. Instead, adolescents appear to function better in cognitive tasks where they have an existing strong knowledge base (Byrnes, 2003) or have received specific training designed to accelerate performance (Iqbal & Shayer, 2000). These findings lead many researchers to favour domain specific models of cognitive development in adolescence. According to such models, developmental progress depends at least in part on the cognitive opportunities, tasks and challenges to which adolescents are exposed (Byrnes, 2003). Alternative accounts of adolescent reasoning have been advanced more recently, drawing upon information-processing theories, and arguing t hat what really underpins development in adolescence is not so much changes in formal logical skills as changes in processing capacity or efficiency – such as improved memory skills or attention span (Keating, 1990). These capacities may also be linked to ongoing neural developments, as there is now substantial evidence that the frontal lobes continue to develop during adolescence (Byrnes, 2003).

ADOLESCENCE

COGNITIVE DEVELOPMENT
Less immediately visible is an intellectual growth spurt during this period (Andrich & Styles, 1994). The young person is becoming capable of thinking about the world, and dealing with the challenges it presents in new and more powerful ways.

The period of formal operations
In Piaget’s view, the cognitive advances of middle childhood (the concrete operational period) are limited because they can only be applied to relatively accessible problems, i.e. tasks concerned with the physical ‘here and now’, or easily imagined scenarios. During adolescence, many individuals progress beyond this limitation, and are able to deal with more abstract cognitive tasks. Piaget calls this (the final stage in his model) the period of formal operations. [period of formal operations the last of Piaget’s stages of intellectual development, when thought is no longer dependent on concrete operations tied to immediately present objects and actions, but is based on reasoning about abstract propositions and the evaluation of alternative possible outcomes] Once again, Piaget and his collaborators studied this phase of development in great detail (Inhelder & Piaget, 1958). They set a number of tasks for children and adolescents, designed to illuminate changes in their reasoning processes. In one task, participants were presented with a set of pendulums, with objects of different weights suspended from strings of different lengths. The task was to determine what influences the speed with which the pendulum swings: is it the weight of the object, the length of the string, the height from which the object is dropped, the speed with which it is pushed, or some combination of factors? Children still in the concrete operational stage set about the task rather haphazardly. They tried guessing and random combinations of actions but were unable to isolate the effects of a single factor. Adolescents (aged 14–15) who had reached formal operations worked in a much more systematic fashion. They tested the effects of varying a factor (e.g. length of string) while holding the other factors constant (e.g. using the same weight for each trial), keeping track of the different manipulations and possibilities. In due course, they came up with the correct answer. (What do you think? Test your own formal operational reasoning.

Another problem devised by Inhelder and Piaget (1958) was a chemistry task, which involved creating a yellow solution from five unidentified liquids, each initially in its own test tube. Some combinations of colours achieved this outcome, and others removed it. How would you set about finding which combinations work, and then how to make the colour disappear? Concrete operational children favoured a trial-and-error approach: they kept trying random mixtures. Some children never worked it out, some hit occasionally on a combination that worked but were not sure exactly how they had done it, or how to reverse the process (i.e. make the colour disappear). The formal operational thinkers were much more systematic. They contemplated the range of possible combinations, formulated hypotheses, and tested them sequentially; they also kept a record of the combinations they had tried and the outcomes. In these (and many other) tasks, formal operational thinkers demonstrate not simply that they are systematic and able to keep track of their attempts, but that they are able to formulate abstract hypotheses about possible outcomes. They are able to conceive of different propositions about the same set of factors, and to work out means of testing them to achieve a resolution. Formal operational thought is not restricted to tackling science education puzzles. Again, from a Piagetian perspective, the important point is that this higher level of reasoning enables young people to deal with many aspects of the world more profoundly. They now have access to more abstract ideas and principles, and some become very interested in the principles governing the broader social environment. For example, many adolescents develop an interest in political issues, human rights, feminism, the environment or spiritual matters (Klaczinski, 2000) – all concerns that reflect their ability to conceive of alternatives to the present reality. This is a time of ‘great ideals’ (Piaget & Inhelder, 1966).

ADOLESCENCE

PHYSICAL DEVELOPMENT
Through most of childhood, people grow at a fairly steady pace – about 5–10 cm and 2–3 kg per annum. But with the beginnings of adolescence, most individuals undergo another radical change, often called a growth spurt. In girls, this typically occurs at around age 10 to 13; in boys, it occurs between 12 and 15. Growth is quite rapid compared to earlier in the lifespan – a girl may add around 9 kg in a year, and boys around 11 kg (Tanner, 1962). The transformations of puberty – as the developing body commences the changes that allow it in turn to contribute to the reproductive process – are almost as radical. Secondary sexual characteristics A particularly important physical change during puberty is the emergence of secondary sexual characteristics. In girls, this means an increase in subcutaneous fat and rounding of the body, the beginnings of breasts and, towards the end of the spurt, pubic hair and the menarche (the first period). In boys, the penis, testes and scrotum begin to enlarge, pubic hair appears, the voice begins to deepen, and muscles grow and strengthen. At around 13 to 14, most boys experience ejaculations or nocturnal emissions (wet dreams). Underlying all of these external changes, there are important hormonal developments, due to the increased production of estrogen (in girls) and androgen (in boys). Young people are now heading towards their mature size and form, but the pace of development varies markedly across individuals. These developmental changes are important from a psychological perspective, because they affect the young person’s sense of self and relations with others (Brooks-Gunn & Paikoff, 1992; Durkin, 1995). Unlike the tadpole, human adolescents are very much consciously aware of the changes they are undergoing. The emergence of the secondary sexual characteristics prompts them to think of themselves as young adults, and to change their appearance and activities accordingly.

The effects of variation
Variations in the pace of development lead to complex outcomes. In some respects, those who mature early tend to have an advantage in that they are seen – and treated – as more adult-like. Some young people, especially males, gain from this, developing greater popularity and confidence that can endure into adult life ( Jones & Bayley, 1950). In contrast, late matures may experience some insecurities as they compare themselves with their peers who are ahead of them in the prized achievement of growing up (Alsaker, 1992). But there can be drawbacks to early maturation, too. For example, some early maturing boys are drawn into activities (like truancy or delinquency) that get them into trouble with parents, teachers and other authorities (Ge et al., 2001). Some early maturing girls report higher levels of psychosomatic distress during their teens. This is perhaps because their earlier involvement in activities such as dating and other people’s expectations of them to behave as adults lead to pressures they are not yet equipped to handle (Ge, Conger & Elder, 1996; Graber et al., 1997).

ADOLESCENCE

It is difficult to decide exactly when adolescence begins or ends, as both boundaries are subject to individual variation. Is a person an adolescent when he or she reaches a particular age – say, the teens? Some people at this age are already relatively mature sexually, whereas others are still pre-pubertal. Intellectual maturity can vary just as widely. And when is adolescence complete – at the end of the teens, at 21, or later? Some people have adult responsibilities – perhaps a job and family – by their late teens, while others can be found skateboarding around university campuses, free of commitments and still quite unsure of where they are heading in life, into their mid 20s. For these reasons, psychologists working on adolescence tend to define the period broadly, as a time of transition between childhood and adulthood, acknowledging that the timing and pace of development is subject to considerable variation.