An Introduction to Developmental psychology by A. Slater and G. Bremner (third edition) - Chapter 16

Adolescents can see both figures in ambiguous figures, while young children can only see one, or take longer to see the other. This suggests increased flexibility of perception. Adolescents have a superior ability to allocate attentional resources. Selective attention is the ability to allocate attentional resources and focus on a specific topic. Adolescents have superior selective attention. Young children divide their attention, while adolescents selectively focus their attention.

Speed of processing refers to the amount of time needed to carry out any given mental calculation. Speed of processing develops rapidly during childhood and continues to develop during the adolescent years. This development is partially driven by the maturation of white matter in the brain.

There is rapid development in face processing abilities during childhood and adolescence. The encoding switch hypothesis claims that different information about faces is represented in memory by children of different ages. Children prior to the age of 10 primarily use information about individual features and adolescents use information about the configuration of features. Featural processing is a tendency to process the separate features of the face, as opposed to perceiving the relationship between the parts. Configural processing is processing that pays attention to the overall spatial layout of individual features. Adolescents only encode the essential information of faces. Hormonal changes during puberty might account for a poorer facial recognition between the age of 11 and 14.

Adolescents may have a better memory, because they use different memory strategies to remember things, where young children only use basic mnemonics, such as the rehearsal strategy. Adolescents can make use of the organisation strategy, clustering groups of items in memory when they are to be remembered.

There are three important characteristics of adolescents’ general intellectual ability.

1. Adolescents’ general intelligence abilities are significantly advanced compared to children younger than 10 years of age.
2. There are differences in development speed of different intellectual abilities.
3. Adolescents’ IQ is relatively stable and does not change greatly as age increases.

Children’s general intellectual abilities are more unstable at a younger age than in later years. There are two types of intelligence:

1. Fluid intelligence
   This is the person’s ability to think and reason abstractly as measured by culture-free reasoning tasks. This improves up until the age of 30 and then slowly declines.
2. Crystallised intelligence
   This is the store of information, skills and strategies acquired through education and prior experience. This keeps improving up until late in life and then remains stable. It is associated with information processing in the neocortex, the most recently developed area of the cerebral cortex.

The Flynn-effect is the increase in IQ in generations. There are generational IQ gains.

Reasoning is the set of mental processes by which we draw conclusions on the basis of information known to us. There are three types of reasoning:

1. Deductive reasoning
   This is from the general to the specific. 
2. Inductive reasoning
   This is from the specific to the general.
3. Analogical reasoning
   This is comparing a problem to a similar problem that has been solved previously.

Performance with reasoning varied considerably depending on the form of the premises and the conclusion. Younger people are better at reasoning if the statements are concrete, rather than abstract, although this improves with age. Children are better at deductive reasoning than inductive reasoning. Children are not good at solving analogies, but this increases rapidly with age after the age of 9 or 10. There are three stags in analogical reasoning:

1. Analogies with familiar elements (age 9 or 10)
2. Concrete relations among elements are considered in analogies (age 12)
3. Full understanding, second-order analogies can be used (age 13 or 14)

Second-order analogies are analogies that require crystallised intelligence

This term is used by Piaget to refer to the unique way of thinking in adolescence. Adolescents think rationally and logically and make use of abstract thought. Adolescents make use of interpropositional thinking. This is thinking where the individual is able to relate one or more parts of a proposition to another part to arrive at a solution to a problem. Intrapropositional thinking is the thought of the child in the concrete operations stage, which includes concrete content rather than abstract symbols. Adolescents apply logical thinking to the possible and not just to the real.

Adolescents can make use of hypothetico-deductive reasoning. This is the ability to develop theories in an attempt to explain certain phenomena, generate hypotheses based on these theories and systematically devise tests to confirm or refute these hypotheses. Children in the concrete operational stage only accept confirmatory evidence and dismiss counter-evidence. Adolescents can reason like scientists.

The balance scale task shows the thinking of adolescents because they can think in a combinatory manner (combining rules) and children cannot. The pendulum problem showed that adolescents think in a more systematic way than children do.

It is unclear whether all adolescents reach the formal operational stage. Piaget seemed to overestimate the average adolescent. Adolescents’ ability to use formal operations appears to develop gradually. In early adolescence, formal operations are not fully developed, nor are they used consistently. Training and instruction might be useful in developing formal operations. This shows that the role of experience is big in developing formal operations.

The information-processing approach states that adolescent thinking is a process of obtaining information from the environment, storing that information in the short-term and long-term memory systems and using various rules and strategies to manipulate information. It views the adolescents as rule-based problem-solvers. Siegler proposed that children use a single rule and that the rules they use get more complex with age. Adolescent thinking is rule-based and the rules are domain-specific.

The children and adolescents as an intuitive scientist approach state that both children and adolescents are capable of constructing theories to explain how the world operates in a law-like manner and conducting experiments to confirm them. The difference with Piaget is that there is no overarching principle that a child of a particular age can use to solve all problems, but that knowledge is domain-specific. There are three common flaws in children’s and adolescents’ use of theories:

1. Failure to separate theory and evidence
   This mainly occurs when older children or adolescents already have a favoured theory.
2. Selecting evidence consistent with their theory instead of modifying theory in the face of counter-evidence.
3. A plausible alternative-explanation is needed in order to accept counter-evidence to their existing theory.

Keating summarised five major characteristics associated with the development of thinking in adolescence:

1. Adolescent thinking emphasises the world of possibility
2. The ability to carry out systematic hypothesis testing and scientific reasoning emerges
3. Thinking about the future by planning ahead
4. Adolescents are capable of introspecting about their own thought processes (thinking about thinking)
5. Content of adolescent thinking includes social moral and political issues

Some aspects of thinking mature during adolescence, other aspects continue to develop beyond adolescence.