test 1(a) Flashcards
What are 3 fundamental characteristics of human development?
nature vs nurture
continuity vs discontinuity
universal and context-specific development
Correlational Studies
- investigators look at relations between variables as they exist naturally in the world
- The results of a correlational study are usually measured by calculating a correlation coefficient, which expresses the strength and direction of a relation between two variables (-1.0 to 1.0)
- CORRELATION DOE NOT MEAN CAUSATION
Experimental studies
an experiment is a systematic way of manipulating the key factor or factors that the investigator thinks causes a particular behavior
Independent variable
In experimental studies, is the factor being manipulated
Dependent variable
In experimental studies, is the behavior being observed
1) people are assigned randomly to conditions that differ in the amount of the independent variable they are given
2) an appropriate measure is taken of all precipitants to see whether the treatment or treatments had the expected effect
Longitudinal Studies
same individuals are tested throughout their lives
-most direct way to identify change
What are some limitations of longitudinal designs?
1) Age effects and time of measurements effects are confounded
2) costly and time consuming
3) Measurement methods may become obsolete
4) Participants are lost-don’t want to keep coming ack
5) effects of repeated testing-people get better
Cross-sectional studies:
Developmental differences are identified by testing people of different ages.
- takes less time than longitudinal studies
- since people are tested only once, we learn nothing about the continuity of development
How is development charted in cross-sectional studies?
charted by noting the difference between individuals of different ages at the same point in calendar time (generate correlations)
What can affect a cross-sectional study?
affected by cohort effects which means that difference between age groups (cohorts) may reflect environmental events instead of developmental processes
What information does cross-sectional studies produce?
provides info about age differences:
1) Age effects: relationship between age and a particular aspect of development
2) Cohort effects: effects o being born a member of a cohort or a generation in a historical context
What are four approaches to doing developmental research?
- systematic observation
- sampling behavior with tasks
- self reports
- physiological measures
Systematic Observation
involves watching people and carefully recording what they do
What are the two types of systematic observation?
Naturalistic observation:
observing people in a real-life situation (already know what you are looking for)
Structured Observations: creating a setting to bring out the behavior of interest
Dizygotic Twins
- Fraternal Twins
- two zygotes or fertilized ova (two separate eggs fertilized by two separate sperm)
Monozygotic Twins
- Identical Twins
- one zygote that divides into two individuals
- about 1 in 285 births
Twin Studies
helps us understand human development based on environmental and experiential differences
Genotype
the complete set of genes that make up a person’s heredity (the genetic makeup of an organism)
Phenotype
Observable features that result from the interaction between a person’s genes and enviroment
Polygenic Inheritance
when phenotypes reflect the combined activity of many separate genes
-since so many genes are involved, we cannot usually race the effects of each gene.
Behavorial Genetics
study of the extent to which genetic and enviromental differences contribute to differences in traits
What is the first stage of Prenatal development?
Zygote (month 1)
- fertilized egg reaches the uterus and attaches itself to the uterus
- cell multiplication begins
- internal organs and circulatory system begins to form
- cell division takes place and at the end of two weeks the zygote is the size of a pin-head
- heart begins to beat
- arms and legs begin to form