Lifespan Development

This is Unit Eight of Psychology, Part Two: bonds, stages, and the lifespan. Part One covered how thinking develops. This part covers everything else — how the first bond forms, how families differ, how moral reasoning changes, and what happens across the decades after childhood ends. Two error entries in this part are worth arriving prepared for, because both correct beliefs that are held very widely. The first is that an early attachment classification determines adult relationships. It does not. And the second is about grief — the five responses are real, and they are not a sequence anybody passes through in order. There is also one piece of adolescent neuroscience that explains a great deal. The reward systems mature earlier than the frontal regions that regulate impulse — so for a period there is a strong accelerator and a developing brake. And the part closes on two methods. One for placing a child on the cognitive sequence, including what to do when two tests disagree. And one for reading a developmental study by naming what its design forbids concluding. By the end you will be able to do five things. One: name the attachment patterns and say why classification is not destiny. Two: place a parenting style on its two dimensions. Three: name the three levels of moral reasoning and the critique. Four: say what adolescent brain development explains. Five: place a child on the sequence, including when tasks disagree.

Six entries. The bond, a study that answered what it is built on, a structured assessment, its patterns, and then an error entry — because the classifications are useful and they get read as predictions about a whole life, which they are not.

The bond.

Psych 0900 Attachment

The enduring emotional bond between an infant and a primary caregiver. Enduring is part of the definition — a brief preference is not this.

What it rests on.

Psych 0902 Harlow's Contact Comfort

Harlow found that infant monkeys preferred a soft cloth surrogate over a wire one that provided food. Contact rather than feeding — which overturned the assumption the bond was built on nourishment.

The assessment.

Psych 0904 The Strange Situation

A structured observation assessing attachment through an infant's response to separation and reunion. The reunion is the informative half.

The first pattern.

Psych 0906 Secure Attachment

Exploring freely with the caregiver present, showing distress at separation, and being comforted at reunion. All three — the distress is part of the secure pattern, not a departure from it.

The others.

Psych 0907 Insecure Attachment Patterns

Avoidant, resistant and disorganized responses to separation and reunion. Three distinct patterns rather than one category of not-secure.

And the error.

Psych 0908 The "Attachment Is Destiny" Error

Treating an early attachment classification as a fixed determinant of adult relationships. The classification describes an infant's response in one assessment — it is not a forecast of a life.

Four entries, and they are a two-by-two rather than a list. Demands on one axis, responsiveness on the other — and every style is one position on each. Learning the grid is more useful than learning the four names.

High, and high.

Psych 0910 Authoritative Parenting

High demands with high responsiveness — clear expectations that get explained. Both axes at the top, which is the combination the research generally favours.

High, and low.

Psych 0912 Authoritarian Parenting

High demands with low responsiveness — obedience required, without explanation. The demands are the same as the previous style; what differs is everything else.

Low, and high.

Psych 0914 Permissive Parenting

Low demands with high responsiveness — warmth offered with few expectations attached. Responsive without structure.

Low, and low.

Psych 0916 Uninvolved Parenting

Low demands with low responsiveness — providing neither structure nor engagement. The fourth cell of the grid, and the one with the poorest outcomes.

Two entries. Eight stages spanning a whole life, each built on a conflict rather than a capacity — which is a different kind of stage theory from the one in Part One, and worth noticing as different.

Eight stages.

Psych 0918 Erikson's Psychosocial Stages

Eight lifespan stages, each centred on a psychosocial conflict whose resolution shapes later development. Conflicts rather than abilities — and they continue past childhood, which Piaget's do not.

The best-known.

Psych 0920 Identity versus Role Confusion

The adolescent stage, centred on forming a coherent personal identity against confusion about one's role. The stage that gave the phrase identity crisis its meaning.

Four entries. Three levels of moral reasoning, ordered — and then a critique arguing that the ordering itself encodes a preference, by treating reasoning from justice as more advanced than reasoning from care.

The first level.

Psych 0922 Preconventional Morality

Reasoning based on avoiding punishment and obtaining rewards. The consequences to oneself are the whole content of the judgment.

The second.

Psych 0924 Conventional Morality

Reasoning based on social approval and on maintaining law and order. The reference point moves outward, from oneself to the group.

The third.

Psych 0926 Postconventional Morality

Reasoning based on abstract principles that can override particular laws. Which requires the formal operational capacity from Part One to be available.

And the critique.

Psych 0927 Gilligan's Critique

Gilligan argued the sequence privileges reasoning from justice over reasoning from care and relationship. A criticism of what the ranking treats as advanced, rather than of the observations.

Three entries, and the middle one explains a great deal in a single sentence. Two brain systems mature on different schedules — the one that responds to reward gets there first, and the one that regulates impulse and plans ahead arrives later.

The physical change.

Psych 0929 Puberty

The period of hormonally driven physical maturation producing reproductive capability. A biological event with a large social one attached to it.

The timing mismatch.

Psych 0931 Adolescent Brain Development

Reward-related systems mature earlier than the frontal regions regulating impulse and planning ahead. A strong accelerator and a developing brake, for a period of years — which explains a pattern without excusing anything.

After it.

Psych 0933 Emerging Adulthood

A proposed period from the late teens through the twenties, marked by extended identity exploration before settled adult roles. Proposed — the course marks it as a proposal rather than a finding.

Four entries. Two later periods where something declines and something else does not — and then a model of grief that is among the most widely known ideas in psychology and among the most widely misused.

The middle decades.

Psych 0935 Middle Adulthood

Gradual physical decline alongside stable or increasing expertise and crystallized ability. Both things happening at once, in opposite directions.

Later.

Psych 0937 Late Adulthood and Cognitive Change

Processing speed and fluid reasoning decline while vocabulary and accumulated knowledge are largely preserved. Unit Seven's two intelligences, following different courses exactly as that entry said they would.

The five responses.

Psych 0939 Kübler-Ross's Stages of Grief

Denial, anger, bargaining, depression and acceptance, described as responses to terminal diagnosis and loss. Five real responses, observed.

And the error.

Psych 0940 The "Grief Follows Five Stages" Error

Treating the five as a fixed sequence every grieving person passes through in order. They were described as responses rather than as stages in a queue — and reading them as a schedule tells people their grief is wrong.

Five entries, and the last one is the most honest thing in this unit. A method, three cases — and then what to do when two tests place the same child at different stages. The answer is to report the disagreement, not to take the higher result.

The method.

Psych 0942 Placing a Child on Piaget's Stages

Testing for each stage's marker capacity and naming the highest one reliably present. Reliably is the qualifier that keeps a single success from deciding it.

The first case.

Psych 0943 Placing a Child at Sensorimotor

A child who does not search for a fully hidden toy is placed at sensorimotor, before object permanence. One test, one boundary.

The second.

Psych 0945 Placing a Child at Preoperational

A child who uses symbols freely and fails conservation is placed at preoperational. Two observations together, not one.

The third.

Psych 0947 Placing a Child at Concrete Operational

A child who conserves quantity and cannot reason from a premise they believe false is placed at concrete operational. The second half is the ceiling test — it is what the next stage adds.

And disagreement.

Psych 0949 When Two Piagetian Tasks Disagree

When two tasks place the same child at different stages, the disagreement is reported rather than resolved by choosing the higher result. Which is an admission that the sequence is less uniform than the stages suggest.

Four entries closing the material, and the method has three steps with the third being the useful one. Name the design. Name the confound it carries. Then name what that confound forbids you from concluding.

The method.

Psych 0951 Reading a Developmental Study Design

Naming the design, then the confound that design carries, then what that confound forbids concluding. The third step is the one that changes how a paper gets read.

The first design.

Psych 0952 Reading a Cross-Sectional Design

A cross-sectional design supports statements about age differences and not about change within a person. Two very different claims, and only one is available.

The second.

Psych 0954 Reading a Longitudinal Design with Attrition

A longitudinal design with heavy attrition supports conclusions only about the participants who remained. Who left is not random, which is what makes the restriction necessary.

And the third.

Psych 0956 Reading a Sequential Design

A sequential design follows several cohorts over time, allowing age effects and cohort effects to be separated. It answers the problem the first two designs each had.

One capstone, and it refuses to pick a theory. One developmental outcome, run through four separate accounts — cognitive, sociocultural, attachment, psychosocial — and then a comparison of what each one manages to capture.

The capstone. One child, four accounts.

Psych 0958 One Child, Four Theories

Running the same case through cognitive, sociocultural, attachment and psychosocial accounts and comparing what each captures. Both parts of this unit, applied to one child at once.

Five things you can now do, and Unit Eight is complete. You can name the attachment patterns — secure, avoidant, resistant, disorganized — and say that a classification describes an infant's response in one assessment rather than forecasting an adult life. You can place a parenting style on its two dimensions, demands and responsiveness, and read the four styles off the grid. You can name the three levels of moral reasoning and state the critique — that ranking justice above care is a preference built into the sequence. You can say what adolescent brain development explains: reward systems maturing before the regions that regulate impulse, which accounts for a pattern without excusing anything. And you can place a child on the cognitive sequence, naming the highest marker reliably present — and reporting a disagreement between tasks rather than resolving it upward.