Chapter 3 Part 1
Developing through the Life Span
Psychology 101: General
Instructor: Mark Vachon
Prenatal Development: Genes

Chromosomes
containing DNA
(deoxyribonucleic acid)
are in the nucleus of a
cell
Prenatal Development

Zygote: the fertilized egg



Identical Twins


46 chromosomes total
23 from sperm cell, 23 from egg
Fertilized egg splits into two halves
Fraternal twins

Two eggs fertilized by two sperm
Prenatal Development (cont.)

Embryo: 2 weeks to 2nd
month


Teratogen: any substance that can
cause a defect
Fetus: 9 weeks to birth

Length grows 20 times, weight from
1 ounce to 7 pounds
At Birth

Competent Newborn:


Born with survival reflexes
Senses:






Touch fully developed
Taste developed
Hearing is functional
Preference for faces
Recognizes smell of mother
Temperament:


Reactive, intense, fidgety
Easygoing, quiet, placid
Physical Development

Brain Development



At birth, born with most brain cells you will need
After birth, neural networks grow
Critical Period:


Period in life when exposure to something is needed
Example: before adolescence, need exposure to language
Motor
Development
Cognitive Development
Jean Piaget



Children’s mind develops in stages
Children are active thinkers: build Schemas
4 stages:
1.
2.
3.
4.
Sensorimotor
Preoperational
Concrete Operational
Formal Operational
Cognitive Development (cont.)
Sensorimotor: birth to age 2
1.


Object Permanence: an object exists if not in sight, 6
months
Stranger anxiety
Preoperational: 2 to 7
2.


Egocentrism: difficulty taking another point of view.
Lack Conservation: quantity remains even if the shape
changes.
Theory of Mind
Cognitive Development (cont.)
Concrete Operational: 7 to 11
3.


Conservation: understand that altering the appearance
does not change the amount
Reversible Thinking: ability to mentally reverse actions
Formal Operations: 12 to adult
4.


Understand abstract concepts
Hypothetical thinking