Research methods and prenatal development

Operationalize

define the concept of interests so that it is observable and measurable

Correlational methods

seek to identify whether an association between two factors exists

Positive correlation

As one increases, the other increases

Negative correlation

As one increases, the other decreases

Small magnitude

R = +- .2

Moderate magnitude

r = +- .5

Large magnitude

r = +- .7

independent variable

variable manipulated by researchers

dependent variable

variable measured by researchers to see if it changes as a result of manipulation

self reports

info provided by people directly. For example, verbal interview and written survey

naturalistic observation

naturally occurring behavior in people’s usual settings

structured observation

create a situation in which the behavior of interest is likely to occur

Fertilization

The sperm pushes through the membrane of the ovum, and the two reproductive cells fuse into one zygote

Ovum always carries what type of Chromosome

X chromosomes

Sperm always carry what type of chromosomes

Either an x or y chromosome

intersex

born with physical features that don’t completely fit the usual expectations for a male or female body

genotype

A set of genes inherited from parents

phenotype

observable characteristics of a person, influenced by genotype and environment.

dominant trait

expressed when two competing traits are present

recessive trait

present within an organism but not expressed

behavioral genetics

Studies the effects of genetics on our behavior and psychological characteristics

monozygotic twins

one original zygote splits after fertilization, share 100% of genes.

dizygotic twins

Two separate sperm fertilize two separate ova, share 50 % of genes

twin studies

if monozygotic twins are more similar than dizygotic twins on a trait, suggests stronger role for genetics.

adoption studies

if adopted children are similar to their biological parents on a trait -> genetics; if adopted children are similar to their adoptive parents -> environment

germinal stage

fertilization to 2 weeks: zygote implants to uterine wall and rapid cell division

embryonic stage

2 to 8 weeks. embryos major organs and basic anatomy start to develop in three layers.

ectoderm- outer layer

skin, hair, teeth, brain, spinal cord, sense organs

mesoderm- middle

muscles, bone, blood, circulatory system.

endoderm-inner layer

digestive system, liver, pancreas, respiratory system.

fetal stage

8 weeks to birth. rapid growth continues. brain doubles in size.

first trimester

often feel ill or tired

second trimester

expanding body

quickening

first feelings of fetus moving around

Cross sectional designs

Compare people of different ages on the same measure to infer how changes occur over the course of development

Longitudinal designs

follow a single group of people as they grow. Changes occur over the course of development

sequential designs

a combination of cross-sectional and longitudinal designs

research ethics

Key rights of people as participants in research: For example, protection from physical harm, up-front consent, and privacy of data

third trimester

Getting very large and waiting for birth. Backaches, leg cramps, heartburn, and insomnia.

Braxton hicks contractions

The uterus occasionally contracts to get ready for delivery

What are the things about a pregnancy that makes it healthy?

Nutrition, Exercise, Age, and Stress

Infertility

Inability to conceive after 12-18 months of trying

In vitro fertilization or IVF

Ova and sperm are fertilized outside the uterus, and then re-inserted to implant

Teratogens

Threats from the outside that cross the placenta to harm the fetus. For example, Aspirin, caffeine, alcohol, smoking, and eating fish.