HUMAN DEVELOPMENT * Exploring Human Development * Nature or Nurture? * John Locke – thought of new born as a blank slate, believed that experiences provided by environment during childhood have a profound and permanent effect. * Jean-Jacques Rousseau – believed children are capable of discovering how the world operates and how they should behave without instruction from adults. * Arnold Gesell – found that motor skills developed in sequence of stages, the order of the stages and the age at which they develop are determined by nature and relatively unaffected by nurture (apart from extreme circumstances).
Maturation: natural growth/change that unfolds in a fixed sequence relatively independent of the environment. * John B Watson – founder of the behaviours approach to psychology. Claimed the environment not nature moulds/shapes development. * Jean Piaget – suggested nature and nurture work together and influences are inseparable and interactive. * Nature/Nurture operate together to make all people similar in some respects. Eg; achieving milestones of physical development in the same order at roughly the same rate. * Nature/Nurture operate to make each person unique. Nature of inherited genes and the nurture of widely different family/cultural environments produce differences among individuals. Eg; intelligence, language skills and personality. * Hereditary creates predispositions that interact with environmental influences that produces the developmental outcomes we see in individuals. * How much they contribute varies from one characteristic to another. Heredity and environment correlate and influence each other.

* Beginnings * Prenatal Development: * Zygote – a new cell, formed from a father’s sperm and a mother’s ovum, carries a genetic heritage from both mother and father. * Stages – * Germinal Stage: zygote divides into many more sells which form an embryo. * Embryonic Stage: embryo develops heart, NS, stomach, oesophagus, ovaries/testes. * Foetal Stage: foetus – the developing individual from the 3rd month after conception till birth. * Prenatal Risks – * Placenta forms from outside layer of zygote and attaches itself to mother’s uterus through umbilical cord. Severe damage can occur if the baby’s mother takes certain drugs, exposed to toxic substances, or has certain illnesses while organs are forming in embryonic stage. * Teratogens – harmful substances that can cause birth defects. (Alcohol/smoking/drugs.) * Critical period – an interval during which certain kinds of growth must occur if development is to proceed normally. (eg; embryonic stage teratogens affect/defect/intellectually disabled; foetal stage teratogens affect size, behaviour, intelligence & health) * The Newborn: * Vision and Other Senses – * Infants can see at birth but vision is blurry, eyes and brain still need time to grow and develop. * Stare longest at objects with large visible elements, movements, clear contours & and a lot of contrast between lighter/darker areas. * Four months old can categorise objects according to shape, but takes approximately seven months to develop depth perception. * Hear poorly at birth, isn’t as sharp as adults till well into childhood. * Can hear soft voices and notice difference between tones about a note apart on musical scale. * Turn heads towards sounds. * Hearing attuned to sound of speech. * Smell is similar to adults but less well developed. * Sensory abilities are important for survival and development because they focus attention on caregiver and draw interaction with infant. * Reflexes and Motor Skills – * Reflexes: simple, involuntary, unlearned behaviours directed by the spinal cord without instructions from the brain (grasping, rooting, sucking.) * Most reflexes disappear after the first 3-4 months when the brain is more developed and allows voluntary control of muscles. * Develop motor skills – roll over, sit up, crawl, stand and walk. * Skills don’t just appear, takes the development of enough muscle strength to support and some active experimentation to get the job done. * Motor development results from a combination of maturation and experience (nature/nurture influence each other.) Brain controls developing behaviour, but its own development is affected by experience, including efforts to build motor skills.

* Infancy and Childhood: Cognitive Development * Changes in the Brain – * Neural networks connecting brain cells grow increasingly complex and then (with pruning) more efficient. * Infancy the cerebellum is most mature part of the brain, allows infants to display simple associative abilities (eg; sucking more when see mothers face/hear her voice.) * 6-12 months neurological development in the medial temporal lobe of cerebral cortex makes it possible for infants to remember and imitate an action they have seen earlier. * Development in the frontal cortext, later in childhood, allows for the development of higher cognitive functions such as reasoning.