Development
Characteristics influenced by heredity
The Physical Development researchers believe that although environment exerts an important influence on human development, physical traits are the ones more evidently influenced by heredity. Personality and intellectual characteristics are also affected by it Mechanism of heredity: Transmission of genetic characteristics the process begins from the moment of conception; a sperm from the father unities with the ovum egg of the mother to form zygote, a single cell/one celled product, containing the complete genetic package for the one to be born much later.
Physical Characteristics- The physical characteristics of people include things like hair and eye color, skin pigmentation, height, weight, gender and others.
Intellectual Characteristics- The Intellectual characteristics of people include thing like memory, intelligence, Age of language acquisition, reading disability, and mental retardation.
Emotional characteristics and disorders- Includes shyness, extraversion, emotionality, anxiety etc.
Earliest Development
Embryo- A development zygote that has a heart, a brain, and other organs. 2-8 weeks.
Fetus- A developing individual, from 8 weeks after conception until birth.
Genetic Influence on the Fetus
Phenylketonuria (PKU)- A child born with the inherited disease phenylketonuria cannot produce an enzyme that is required for normal development.
Sickle cell anemia- About 10% of the African-American population has the possibility of passing on sickle cell anemia, a disease that gets its name from the abnormally shaped red blood cells it causes.

Tay-Sachs disease- Children born with Tay-Sachs disease, a disorder most often found in Jews of eastern European ancestry, usually die by age 3 or 4 because of the bodies inability to break down fat.
Down Syndrome- Down syndrome, one of the causes of mental retardation, occurs when the zygote receives an extra chromosome on the 21st pair at the moment of conception.
Prenatal Environment influences
Mothers nutrition- What a mother eats during her pregnancy can have important implications for the health of her baby. Seriously undernourished mothers cannot provide adequate nutrition to a growing fetus, and they are likely to give birth to underweight babies.
Mothers illness- Several diseases that have a relatively minor effect on the health of a mother can have devastating consequences for a developing fetus if they are contracted during a sensitive period of embryonic or fetal development.
Mother use of drugs- Mothers who take illegal, physically addictive drugs such as cocaine run the risk of giving birth to babies who are similarly addicted. Their newborns suffer painful withdrawal symptoms and sometimes show permanent physical and mental impairment as well.
Alcohol- Alcohol is extremely dangerous to fetal development.
Development of the senses
Milestones of physical development, birth to age 2
3.2 months- rolling over 3.3 months-grasping rattle 5.9 months- sitting without support 7.2 months- standing while holding on 8.2 months- grasping with thumb and finger
11.5 months- standing alone well 12.3 months- walking well 16.6 months- walking up steps 23.8 months- jumping in place
Parenting styles
Authoritarian parents- Parents who are rigid and punitive and value unquestioning obedience from their children.
Permissive parents- Parents who give their children relaxed or inconsistent direction and, although they are warm, require little of them.
Authoritative parents- Parents who are firm, set clear limits, reason with their children, and explain things to them.
Uninvolved parents- Who show little interest in their children and are emotionally detached.
Erik Erikson's 8 Stages The first stage is Trust vs. Mistrust and is from ages zero to about one and a half years. The social concerns of this stage are feeding, changing, and sleeping of the newborn and the baby’s relationships is generally with the parents