A baby has nearly all its neurons. So why does its brain triple?

From a tube to a brain

• In the first few weeks after conception, the nervous system is a simple neural tube.
• Its front end swells into three parts: the forebrain, midbrain and hindbrain. The rest becomes the spinal cord.

Built from the bottom up

• The parts mature in order, from the oldest, deepest parts to the newest.

What grows after birth

• A neuron is a nerve cell that carries signals. A newborn has almost all its neurons.
• Neurons pass signals across tiny gaps called synapses.
• After birth, neurons branch and form huge numbers of new synapses. Fatty myelin sheaths and support cells add weight.
• Rarely used synapses are later removed: synaptic pruning.
• The nervous system: central (brain, spinal cord) and peripheral (nerves to the body).

Stages of development

IQ tests

• Intelligence is the ability to learn, reason and solve problems.
• An IQ test uses standardised tasks (vocabulary, patterns, memory) and compares a score with others of the same age.
• Scores are scaled so that the average is 100.
• Strength: standardised, reliable, and predicts school achievement.
• Weakness: questions can be culturally biased, and tests sample only some abilities.

A hidden toy is "gone" to a baby; a year later they find it. Why?

Schemas: how knowledge is built

• A schema is a mental framework of knowledge about something, built from experience.
• Assimilation: fitting a new experience into an existing schema (a toddler calls a cow "doggy").
• Accommodation: changing a schema, or making a new one, when an experience doesn't fit ("cows say moo").
• Children build schemas actively, by exploring.

Four stages in a fixed order

• The stages are invariant: every child goes through them in the same order without skipping, though ages vary.
• Maturation makes a child ready for the next stage; exploring the world moves them on.

Three ideas from the early stages

• Object permanence: knowing that an object still exists when out of sight. It develops at about 8 months, in the sensorimotor stage. Before that, out of sight is out of mind.
• Egocentrism (pre-operational): seeing the world only from your own point of view.
• Animism (pre-operational): believing objects are alive and have feelings ("the sun follows me because it likes me").

Piaget in the classroom

• Readiness: a child learns a concept only when at the right stage, so teaching matches the stage.
• Active learning: children learn by exploring and doing; the teacher sets up tasks, not just tells.
• Concept of intelligence: not a fixed amount but a way of thinking that develops as schemas grow.
• Key stages group school years by age (KS1 5–7, KS2 7–11, KS3 11–14), roughly matching the stages.

Pour juice into a taller glass and a 5-year-old sees more. Why?

Conservation

• Conservation: understanding that a quantity stays the same when its appearance changes (number, volume, mass).
• Pre-operational children fail because of centration: they focus on one feature, such as the height of the juice, and ignore the width.
• They also lack reversibility: they can't mentally pour the juice back.
• At about 7 (concrete operational), children use decentration (weighing height and width together) and reversibility, so they conserve.

Egocentrism and how it fades

• Egocentrism: a pre-operational child assumes other people see what they see.
• Piaget tested this with a model of three mountains, asking which view a doll could see. Young children tended to pick their own view.
• Egocentrism declines as children learn to decentre from their own viewpoint, mainly during the concrete operational stage: the reduction of egocentricity.

Criticism: reductionism and holism

• Reductionism breaks behaviour into simple parts; holism considers the whole person and situation.
• Piaget's theory is fairly reductionist: it explains thinking mainly by maturation through fixed stages and underplays the social situation, such as how questions are asked.
• Children conserve more when the change looks accidental or the question is asked once, so the whole situation matters.
• In its favour, stages make the theory testable and useful for schools.

Telling a child "you're so clever" can make them do worse. Why?

Two mindsets

• A mindset is a belief about whether your abilities can change (Dweck).
• Fixed mindset: ability is fixed. Needing effort means you're not clever, so you avoid challenges and give up after failing.
• Growth mindset: ability grows through effort, practice and good strategies. Mistakes are chances to learn.

Praise and beliefs about ability

• Person praise ("You're so clever") links success to a fixed trait; after failing, the child decides they aren't clever.
• Praise for effort (process praise: "You worked hard") links success to things they control, building a growth mindset.
• Example study: Mueller and Dweck (1998): children praised for intelligence did worse after failing than those praised for effort.

Mindsets in school, and the critics

• Schools praise effort and strategy, say "not yet" instead of "fail", and teach that the brain changes with practice.
• Large reviews find mindset programmes raise grades only slightly on average, perhaps more for students at risk of low achievement.
• Nature/nurture: Dweck stresses nurture (beliefs, praise, effort). Critics point to nature: twin studies suggest intelligence is partly inherited. Most see an interaction.

Teach a "visual learner" with pictures: will they learn more?

The learning styles idea

• A learning style is a person's preferred way of taking in information, e.g. visual, auditory or kinaesthetic (VAK).
• The claim: students learn more when teaching matches their style.
• In one survey, 93% of UK teachers believed this.

Willingham's criticism

• Daniel Willingham, a cognitive psychologist, calls learning styles a myth: there is no good evidence that matching teaching to a style improves learning.
• People do have preferences, but in controlled tests students taught "in their style" don't learn more.
• The best method depends on the content, not the learner: everyone learns a map from a picture and pronunciation by listening.
• People are more alike than different in how they learn.

What does help learning

• Meaning: you remember what you think about ("memory is the residue of thought"). Lessons should make students think about what material means.
• Factual knowledge precedes skill: you need facts before you can think critically or solve problems in a topic. Known facts free up working memory.
• Practice and effort: practise until knowledge and skills become automatic. Ability can grow with effort.

Willingham in schools

• Teaching through meaning, not learning styles: plan around what students should think about; fit the method to the content; don't sort students by style.
• Combine with growth mindsets: praise effort and strategy; treat mistakes as part of learning.
• Nature/nurture: Willingham stresses nurture (knowledge, practice, meaning) but accepts genes affect ability. Critics say he says little about individual differences.

Big ideas

• The brain starts as a neural tube; the forebrain, midbrain and hindbrain develop into the cortex, thalamus, brain stem (medulla) and cerebellum, maturing from autonomic functions to sensory processing, movement and cognition.
• After birth the brain grows mainly by forming synapses and myelin, and then pruning unused synapses.
• The brain keeps developing through the pre-natal stage, childhood, adolescence and adulthood; IQ tests measure intelligence but can be culturally biased.
• Children build schemas through assimilation and accommodation as they explore the world.
• Thinking develops through four invariant stages: sensorimotor (object permanence), pre-operational (egocentrism, animism), concrete operational (logic about real objects) and formal operational (abstract thought).
• Application, the changing role of education: key stages, readiness, active learning and the concept of intelligence.
• Pre-operational children fail conservation tasks through centration and a lack of reversibility; at about 7 they decentre, and egocentrism reduces.
• Piaget's (1952) conservation of number study supports the stages, but the theory is criticised as reductionist for underplaying the social situation.
• A fixed mindset sees ability as fixed; a growth mindset sees it as growing through effort, practice and strategies.
• Praise for effort builds a growth mindset; Blackwell et al. (2007) found it can be taught, though critics argue nature also limits ability.
• Evidence supports the theory, but large reviews suggest school mindset programmes have only small average effects.
• Learning styles (e.g. VAK) are a popular idea, but Willingham argues that matching teaching to them doesn't improve learning; the method should fit the content.
• What helps: thinking about meaning, factual knowledge before skill, and practice with effort.
• Application, the changing role of education: teach through meaning, not learning styles, and build growth mindsets. Nature/nurture: the theory stresses nurture.