3 copies of chromosome 21. 1 in 800. Distinct facial features. Delayed motor devlopment. Speech difficulties. Sociable.
Single X Chromosome (X0). Don't menstruate. Stunted growth. Stubby fingers/toes. Lower spatial, mathematical abilities.
Extra X chromosome (XXY). Undeveloped testes, low sperm count, lang and learning disabilities. At puberty develop both breasts and penis enlargment.
Fragile X syndrome
X chromosome may has split in two. Learning disabilities, behavioural problems, autism, cognitive impairment. 1 in 1000 males. more common in males.
- Germinal period (1st Trimester) - First 2 weeks after conception.
Over first 2/3 days = Meiosis. Day 5 becomes a blastocyst of 150 cells. On day 6 this reaches the uterus. Day 12 - Blastocyst completely buried in uterine tissue, cells specialise into what will be embryos body.
2. Embryonic period (1st Trimester) - 2-8 weeks.
Week 4 Organogenisis - Organs take place. CNS, backbone and spine form. Development of amniotic fluid. Week 8 Heart begins to beat. Brain development. Own blood type. Endocrine system prepares for sexual differentition.
3. Fetal period (2nd/3rd Trimester) - 2months- Birth
(2nd trimester) Neuron proliferation & migration - development of neurons. Week 12 gender differentiation, organs and limbs fully formed. Week 13 hair follicles form. Week 18 swallowing, bones harden. Week 20 respond to light and mother voice, 'Quickening', finger + toenails.
(3rd trimester) Week 24 Skin covered in vernix, hand/startle reflex. 50-75% chance survival - Viable. Week 28 rapid brain development. 90%, Week 32 fetal position, HR activity and movement organised into coherant patterns of sleep/wake.
Motor Milestones - Basic motor skills aquired in infancy and childhood,
Gross motor skills - Large muscle groups (Running, walking)
Fine motor skills
- Gross manipulative skills: Limb movement (Throwing, catching)
- Fine manipulative skills: Precise use of hands and fingers
Maturational theory Global > Specific
- Cephalocaudal trend - Development from head to foot. Physical control and co-ord.
- Proximodistal trend - Development from centre of body to outer peripheral segments.
Dynamic systems theory Nervous system development. Interaction with physical capabilities and environmental constraints. e.g Kicking, walking.
Perception - Interpretation by the brain of the sensory input.
Reflex - Involuntary and unlearned response to stimuli. Presence, strength and persistence of a reflex is important sign of nervous system function.
Survival reflexes of neonates: Breathing + blinking = permanent
Sucking =Disappears by 7mnths (Becomes voluntary)
Rooting = Weakens by 2mnths, disappears by 5.
Grasping =Disappears 3/4 mnths
Babinski = Disappears 12-18 mnths
Stepping = Disappears 2 mnths
Swimming = Disappears 4-6 mnths
Sensory development: Vision -40xs worse than adults, first 3mnths, 8inches distance. Hearing -Newborns can hear better tha see. Taste&Smell - Tastebuds mature early, preference for sweet than bitter. Smell earliest perceptual systems even in utera.
Cognitive Development I - 4 Stages of development
- Sensorimotor 0-2 years
Use senses and motor actions to explore world - Innate reflexes to do this. Repetitive behaviour, then becomes goal directed. Object permanence. Form mental representations - deferred imitation.
2. Pre-operational 2-7 years
Symbolic representation - to develop language, pretend play and problem solving. Egocentric - Cannot see other perspective i.e 3 mountains task.
Intuitive thought (sub stage) 4-7 years - Shift in reasoning. From rational - Perceptive and intuition.
3. Concrete operational 7-12 years
Thoughts more logical and flexible, manipulate mental representations, Grasp concepts of conservation, reversibilty.
4. Formal operations 12+ years
Mental actions on ideas. More abstract thinkers. Age and experience can form hypotheses and systematically test them.
Cognitive Development II
Vygotsky Social-Cultural theory (1978)
Zone of proximal development: Difference between what can do unassisted and what cannot yet do.
Private speech: As children master language, use internal self directed speech to guide thinking and planning.
Scaffolding: Adults structure and simplify env. to facilitate learning.
Guided participation: Ability to learn from interaction with others.
Information processing approach
Perceptual system to explore world + gain info. Info must then me attended to, stored, retrieved and acted upon to gain knowledge.
Case's Neo-Piagetian theory (1978, 1985)
Expanded Piaget's work - Changes within/across stages = inc. central processing speed + WM capacity.
Develops because: Brain development/ Automatisation - Practice and repetition leads to automatic operations. / Formation of Central Conceptual Structures - Children move onto next stage of dev. after
Language and Reading Development
Children can perceive language in the utero- Preference for mothers voice.
Adults use Motherese or Infant non-directed speech when speaking to infacts to help them indentify words.
Speech consists of phonemes. 40 in English language.
Children learn language by: Seperating continuous stream of speech
Universal Phonology - Newborns ability to percieve all languages between 0-12months. Lose the ability after 12months - accent may be affected.
Neural commitment - Learning results in a commitment between neural networks to the patterns of variation that describe a particular language.
Fast-mapping - Children can learn new words from single exposure.
Methods for studying reading: Reaction time, Reading fluency, Reading rate, Eye-tracking.
Phonological awareness - Sensitivity to the sound system of language that enables children to segment spoken words into sounds or phonemes.
Theoretic reading models: Stage models, Dual route models.
Obesogenic eating behaviours: Satiety responsiveness, emotional eating, eating speed.
Food neophobia - Reluctance to eat/avoidance of new foods. Based on sight + previous exp. not taste.
Fussy eating - Rejection of familiar and unfamiliar foods. Based on sight, flavour, texture.
Food refusal - Refusal to eat all or most foods presented, resulting in child failing to meet caloric nutritional needs.
- Functional: Attention/escape
- Externally motivated: Environment or learning dependant e.g lack of experience/exposure
- Internally motivated: Fear or phobias, followed by negative experience.
Exposure -How frequently a child is offered a particular food item. Duration and quality of each experience.
Early exposure to breast milk > Inc. acceptance of bitter tasting fruit and veg. Weaning period effects future tasting preference. Variety, exp. and exposure decreases food refusal.
Modelling and positive reinforcement important in promoting adaptive feeding behaviours. Pressure to eat > Inc fussy eating. Restriction > Overweight
Social development & Theory of the mind
Piaget claimed 3types:
- Sensorimotor (0-2yrs) - Mastering motor skills
- Symbolic/representational (2-6)- Pretend play
- Games with rules (School years) - Understanding co-operation
Types of play:
Solitary play - Unoccupied, onlooker, solitary.
Parellel - Playing near eachother, same material.
Group - Associative, Co-operative
Peer - One that is of equal standing with another.
Friendship - Close relationship between two people. Physical attachment and trust.
Theory of mind - An ability to make inferences about others' mental states. Imp for cogntion and social interaction. E.g False belief task (Maxi task, Sally anne task) Develops 3-4 years.
Distinction between right and wrong and ability to act on it.
How it is studied:
Theoretically, Empirically or Naturalistic observation
- Universal set of rules
- Rights ethic
- Deontological (duty based) - Right/wrongness not in terms of consequence, own features
- Teleological (Goal orientated) - Egoism, Utilitarianism.
Morality not present at birth, product of emotional development.
Explanations - Psychoanalytic, SLT, Cognitive development theory
Measuring morality - Production meaures (Justification), Recognition measures (Mulitiple choice)
Link between morality and prosocial behaviour.
Attachment across lifespan
Attachment - An enduring emotional tie with a significant other.
- Freud (Psychoanalytical) - Oedipus complex
- Bowlby - Parental response determines the quality of represenational models of attachment in the child. E.g secure, insecure.
- Ainsworth (Strange situation) - Attachment representations established in childhood tend to guide the quality of relationships in adulthood.
Mary Main - Adult attachment interview
Autonomous adults: Those who speak about thier childhood without contradictions. > Secure children
Insecure adults: Those who speak about thier childhood with contradictions.
Internal working models of self and other people arising from early experiences in relationships.
Role of oxytocin - Love/bonding hormone. Produced: when giving birth, breastfeeding, ******, small amounts when holding hands.
Artificial oxytocin in form or nasal spray can impact the trust we have for someone.
Old age and Generativity
Ageing - Continual process of change. 'Social' ageing - A fabric of society e.g pension age.
3 factors influencing ageing population: Mortality, Fertility, Migration.
Methodolical problems w/ measuring age related change:
- Age differences - Cohort effects (differences in social behaviour which characterise a generation)
- Age change - Selective attrition (type of people which drop out)
Crystallised intelligence - Resistance to change, stable into 70s. Accumlated exp and wisdom. Verbal and numeric ability from past experiences.
Fluid intelligence - Steady decline from late childhood to adulthood. Using information to solve problems and think abstractly. Independent of learning, experience and education.
Intellectual functioning can be improved by exercise mentally, physically and nutrition.
Dementia. Chronic progressive degeneration of the brain. Memory loss, Problems w/language, disorientation ect. Risk factors - Demographic, lifestyle, illness.
Generativity - 8 stages (Eriksons theory) Active involvement in guiding/teaching of the next generation.
Stage 7, 35-55 - Generativity v stagnation (not seeking outlets of generativity). Parenting
Stage 8, 55+ - Ego-integrity (Looking back with satisfaction) v despair (Anger, frustration)