Human Development

1. Human Development

2. Human development – the study of the human over the life span Genes – our biological blueprints Many of our characteristics are determined at the moment of conception, when 23 chromosomes on the egg pair up with 23 chromosomes on sperm Genotype – all information stored in genes Phenotype – observable characteristics The likelihood of traits being expressed can be worked out with a Punnett Square

3. Chromosomes contain DNA, which is made up of 1,000s of genes (total of ~100,000) • Each gene is a self-replicating segment of DNA capable of synthesizing proteins • Genes are composed of NUCLEOTIDES – a linear sequence of structural units that form DNA – these biochemical bases combine to form 3 billion pairs that determine your individual biological development • The nucleotide base letters are: • A adenine • C cytosine • G guanine • T thymine

4. Some Genetic Abnormalties: 1. Turner’s Syndrome – X - karyotype Sterile, limited secondary sex characteristics, short “webbed” neck 1 in 2,500 live births 2. Klinefelter’s Syndrome – XXY karyotype Sterile, tall, small testicles, passive, reclusive 1 in 1,000 live births 3. Jacob’s Syndrome – XYY karyotype Webbed neck Tall, lower mental ability, high level of testosterone 1 in 1,000 live births 4. Super female – XXX karyotype No specific abnormalities 1 in 1,000 live births

5. 5. Edward’s Syndrome – Trisomy of 18th chromosome Severe mental retardation, most die in infancy 6. Down Syndrome – Trisomy of 21st chromosome Mocaism – some do not have the abnormality in every chromosome; affects level of mental retardation and expression of characteristics HOW DOES PSYCHOLOGY STUDY HUMAN DEVELOPMENT? • Twin studies, adoption studies, temperament research, heritability studies WHO ARE THE PERFECT SUBJECTS FOR STUDYING HUMAN DEVELOPMENT? • Identical twins

6. Monozygotic twins: Dizygotic twins: Twin studies show remarkable similarities in intelligence, temperament, stress response and rates of mental illness **Most ideal twins? Identical twins separated at birth – offer both nature and nurture opportunity for study

7. 3 major issues researched by developmental psychologists: Nature vs. nurture Stability vs. change Continuity vs. stages PRENATAL DEVELOPMENT: • Female is born with 500,000 O ocytes – cells with potential to develop into ovum. 10,000 remain at puberty and approx. 400 will be ovulated in a lifetime • Male begins producing sperm at puberty, and produces it for the rest of his life One ejaculation contains 200 to 400 million sperm!! The odds against you being you are billions to one!

8. When is a female most fertile and likely to conceive? **14 days from the start of her last period Conception occurs! Newly fertilized cell is called a zygote Stages of Prenatal Development: 1. Germinal Period – Conception through 14th day • Ends when zygote implants into the wall of uterus (or cells are sloughed off)

9. 2. Embryonic Period – 2nd through 8th week Critical period of pregnancy (though entire pregnancy is important) – time when environment can have the greatest effect on the organism Development is cephalo -caudal (from the head to the trunk) 6 week embryo

10. 3. Fetal Period – 9th through 40 weeks 20 week fetus Development shifts to Proximo-distal (from trunk outward to limbs) Teratogen – agent that can cause damage to embryo/fetus Most infamous teratogen: thalidomide

11. Age of viability – time when fetus has a 50 – 50 chance of survival if premature: 24 weeks THE NEWBORN: Reflexes: sucking rooting grasping stepping Babinsky 24 week premie Moro

12. Infant intelligence: Recognize mother’s voice Recognize mother’s milk Prefer faces to patterns Imitate facial expressions at 2 weeks

13. Physical Development: Motor milestones of the first 2 years: 1-2 weeks Turns head to follow moving object 6 weeks Rolls from stomach to back 3 months Rolls from back to stomach 6-7 months Sits alone for 1 minute 8-9 months Crawls 10 months Says dada 8-10 months Walks while holding on to something 12 months Takes first steps 14 months Walks alone, says several words 18 months Climbs stairs, says many words 18-24 months Runs, combines two words 24 months Puts on shoes **All require biological maturation

14. Cognitive Development: Jean Piaget’s Theory of Cognitive Development Child develops thinking abilities through stages as their SCHEMAs grow and change Schema – framework for organizing information • New information fits easily into schema sometimes - assimilation • New information requires a change of the schema - accomodation

15. 1. Sensorimotor Stage – 0 to age 2 Babies understand their world through their senses and motor activities Abilities they develop: * Object permanence – an understanding that objects exist when no longer visible * Stranger anxiety * Language develops • All take place at age 8-9 months

16. 2. Preoperational stage – ages 2 through 6 The child is EGOCENTRIC – cannot take another person’s point of view The preoperational child loves to : pretend use animism use artificialism

17. 3. Concrete Operations 7 - 12 The school aged child now uses LOGIC • Egocentrism, animism and artificialism break down • Concrete (not abstract) types of activities such as multiplication and division are possible • Conservation – the understanding that quantity remains the same regardless of shape • The concrete operations child rejects the magical beliefs in Santa, tooth fairy, etc.

18. 4. Formal Operations 13 and up • The child can now use ABSTRACT reasoning • Abstract math and science are possible • Interest in world affairs, religion and politics increase **Critics of Piaget say all of the ages in the stages should begin earlier**

19. Self-concept Development Babies recognize themselves by 15 months Social Development ATTACHMENT – intense infant love for caregiver It lies at the heart of the nature vs. nurture issue • Studied by Harry Harlow • Baby rhesus monkeys were raised in individual cages, away from mother with fabric for a blanket

20. They were distressed when he took the fabric out to wash it; he thought about what it meant • It made him question the conventional idea that babies attach to mothers because they provide food He created surrogate figures: one covered in cloth, the other with a bottle

21. The babies became very attached to the cloth-covered figure He called this need for soft, loving contact CONTACT COMFORT Good news for dad – he can provide contact comfort too! Another key to attachment: familiarity Konrad Lorenz discovered a rigid attachment process in animals:

22. IMPRINTING • He made himself the first thing baby geese or ducks saw after hatching • The bird followed him like he was the mother

23. He also identified a critical period for imprinting

24. Parenting styles and attachment: Mary Ainsworth studied mothers and toddlers - mothers left toddlers in room for a few minutes, how did child respond? She identified 3 types of attachment: 1. Securely attached – child explored around mom, cried when mom left, joyous when she returned 2. Insecurely attached – child was clingy, cried when mom left, angry when she returned 3. Avoidant – little contact between mother and child Could this foretell the relationship patterns of a lifetime??