The Evolution and
Evolutionary psychology emphasizes evolutionary mechanisms that may help explain human commonalities in cognition, development, emotion, social practices, and other areas of behavior.
Behavioral genetics is concerned with the genetic bases of behavior and personality.
Set point is the genetically influenced weight range for an individual, thought to be maintained by a biological mechanism that regulates food intake, fat reserves, and metabolism.
Unlocking the Secrets of Genes
Genes are functional units of heredity; they are composed of DNA and specify the structure of proteins.
Chromosomes are within every body cell, and are rod-shaped structures that carry the genes.
DNA is the chromosomal molecule that transfers genetic characteristics by way of coded instructions for the structure of proteins.
Genome is the full set of genes in each cell of an organism (with the exception of sperm and egg cells).
Linkage studies look for patterns of inheritance of genetic markers in large families in which a particular condition is common.
Genetic marker is a segment of DNA that varies among individuals, has known location on a chromosome, and can function as a genetic landmark for a gene involved in a physical or mental condition.
The Genetics of Similarity
Evolution is a change in gene frequencies within a population over many generations; A mechanism by which genetically influenced characteristics of a population may change.
Natural selection is the evolutionary process in which individuals with genetically influenced traits that are adaptive in a particular environment tend to survive and to reproduce in greater numbers than other individuals; As a result their traits become more common in the population.
Innate Human Characteristics
Infant reflexes: all people are born with certain reflexes such as eye-blinking, sneezing, knee-jerking, sucking, Moro reflex, etc.
An attraction to novelty: curiosity if basic needs have been met.
A desire to explore and manipulate objects.
An impulse to play: most animals, including humans, learn early in their lives through play.
Basic mental skills: as infants develop and grow they begin to display various mental abilities relatively quick. Example: Object permanence.
Our Human Heritage
The origins of perception.
Sensation: the detection of physical energy emitted or reflected by physical objects; It occurs when energy in the external environment or the body stimulates receptors in the sense organs.
Perception: the process by which the brain organizes and interprets sensory information.
Darwin believed facial expressions that exhibit emotions are biological in nature and are an evolved trait in mankind.
Psychologists agree today with Darwin.
90% of all communication is nonverbal.
Sociability and Attachment
Human infants require the constant care, more than any other species in the animal kingdom.
Human infants must form attachments with their care givers in order to survive.
Infants at only weeks old will use smiling in order to communicate to their caregivers.
Behavioral genetics is concerned with the genetic bases of behavior and personality.
Psychology 101 lecture 3
Studying Human Behavior
Experiment: A controlled test of a hypothesis in which the researcher manipulates one variable to discover its effect on another.
Independent variable is the variable that an experimenter manipulates.
Dependent variable is a variable that an experimenter predicts will be affected by manipulations of the independent variable.
Experimental and Control Conditions
Control condition is a comparison condition in which subjects are not exposed to the same treatment as in the experimental condition.
Random assignment is a procedure for assigning people to experimental and control groups in which each individual has the same probability as any other of being assigned to a given group.
Placebo is an inactive substance or fake treatment used as a control in an experiment or given by a medical practitioner to a patient.
Single-blind study is an experiment in which subjects do not know whether they are in an experimental or a control group.
Experimenter effects these are unintended changes in subjects; behavior due to cues inadvertently given by the experimenter.
Double-blind study is an experiment in which neither the subjects nor the individuals running the study know which subjects are in the control group and which are in the experimental group until after the results are tallied.
Advantages and Limitations of Experiments
Research helps us come to well founded conclusions instead of just guessing.
A limitation is that it is hard for any sample to truly represent the total population. Basically, it is hard to generalize findings.
The more controlled the environment the less one is able generalize back to the population. The less controlled the environment the less likely the independent variable had an effect on the dependent variable.
Field research is descriptive or experimental research conducted in a natural setting outside the laboratory.
Evaluating The Results
Once you have your results you must do three things.
Assess how reliable and meaningful they are
Figure out how to explain them.
Descriptive statistics are statistical procedures that organize and summarize a body of data.
Arithmetic mean is an average that is calculated by adding up a set of quantities and dividing the sum by the total number of quantities in the set.
Standard deviation is a commonly used measure of variability that indicates the average difference between scores in a distribution and their mean.
When interpreting the results it is not always easy to explain why a change occurred with the dependent variable.
Two types of studies can be used to gather data.
Cross-sectional study is which subjects of different ages are compared at a given time.
Longitudinal study in which subjects are followed and periodically reassessed over time.
It is important that the research findings have some importance to either the world of science or can be applied to the general population.
Two things to consider when determining importance are:
Effect size: the amount of variance in the data accounted for the independent variable
Meta-analysis: A procedure for combining and analyzing data from many studies; It determines how much of the variance in scores across all studies can be explained by a particular variable.
According to the APA (American Psychological Association) all human subjects used in research must be volunteers.
There should be no physical or emotional harm done to the subjects.
It is important that the human subjects are notified about the research briefed and debriefed about the experiment.
Animals are studied for the following reasons:
To conduct basic research on a particular species
To discover practical applications
To study issues that cannot be studied experimentally with human beings because of practical or ethical considerations
To clarify theoretical questions
To improve human welfare
The Meaning Of Knowledge
Psychology 101 lecture 6
Neurons, Hormones, and the Brain
The Biology Of Memory
The biological perspective offers insights into the mysteries of memory.
Short-term memory appears to involve temporary changes in the ability of neurons to release neurotransmitters.
Long-term memory involves long-term potentiation, a lasting increase in the strength of synaptic responsiveness.
Hormones released by the adrenal glands during stress or emotional arousal enhance memory, possibly by increasing glucose levels in the bloodstream, which in turn alter the effects of neurotransmitters.
High levels of these hormones can interfere with the retention of complex information or tasks; A moderate level is optimal.
The Biology Of Sleep And Dreams
Sleep is necessary for normal mental and physical functioning.
During sleep, periods of rapid eye movement (REM) alternate with non-REM sleep.
During REM sleep, the brain is active and aroused, yet most of the skeletal muscles are limp; Dreams are reported most often in REM sleep.
Some researchers emphasize the weakening of unnecessary synaptic connections during REM sleep; Others emphasize the strengthening of synaptic changes associated with memory for what has recently been learned.
The activation-synthesis theory holds that dreams occur when the cortex tries to make sense of spontaneous neural firing initiated in the pons; The resulting interpretation, or synthesis of the signals with existing knowledge and memories, is the dream.
The Oldest Question
Neurons, Hormones, and the K