9 10 15 The need for psychology Hindsight bias Commonsense describes what has happened after the fact predicts what will happen before the fact Psychology makes the world a better place to live The innovation the lime green fire truck The rationale perceptual psychologists discovery that the human visual system is more sensitive to light with wave lengths between 510 and 570 nm The result lime green fire trucks are more than 3x more likely to be in a traffic accident than red fire trucks The innovation The sequential police lineup procedure in which a witness is shown suspects one at a time instead of all at once The sequential lineup people make absolute judgments which lead to much lower rates of misidentification The result fewer innocent people are wrongfully convicted How do psychologists ask and answer questions the scientific method Theory an explanation using an integrated set of principles that organizes Theory Hypothesis observations Hypothesis a testable prediction implied by a theory We might theorize that the cause of depression is low self esteem one s feelings of self worth We might test this hypothesis by seeing if people who receive a low score for self esteem tend to receive a higher score for depression How do we generate questions General observation Murder of Kitty Lenovese in 1960 brutally murdered yet in the frame of 30 min no one helped her We re less likely to give aid to others is other bystanders are present Darley and Personal experience psychologists understand their own tendencies limitations and Latane foibles Republication seeing whether a basic finding can be observed again with different people and under different circumstances Establishing operational definitions Operational definition a specific statement of the procedures used to define research variables so as to allow others to replicate what we find or don t find An operational definition of intelligence might be the number correct on tests of verbal spatial numerical and reasoning abilities Choosing a research design Three major types of research designs that psychologists use in their research Setting lab field Methods descriptive correlational experimental Descriptive methods The case study an in depth investigation of a single or very few subjects Jean Piaget our ability to use language unfolds through a series of stages theory of cognitive development The survey an investigation of many cases in less depth by asking people to report opinions and behaviors A technique for ascertaining the self reported attitudes opinions or behaviors of people usually done by questioning a representative sample of people one that accurately portrays the population of interest Naturalistic Observation recording behavior in its natural environments and describing it in detail Jane Goodall used naturalistic observation to study chimps She concluded observations made in the natural habitat helped to show that the societies and behavior of animals are far more complex than previously supposed Psychologists have used naturalistic observation to study people s behaviors One study found that people laugh 30 times more often around other people Experimental method other factors constant Purpose to explore cause and effect by manipulating one of more factors while holding Variable anything that can fluctuate Whether it is rainy or sunny warm or cold or whether a person is male or female or in a good mood or a bad mood are all good examples Independent variable aspect of the situation or of individuals that can vary independently of other variables The variables whose effect is being studied Dependent variable the variable that may change in response to manipulations of the independent variable An example does breastfeeding children impact their intelligence later in life The independent variable is whether mothers are assigned to an experimental condition promoting breastfeeding or to a control condition in which they feed their children formula The dependent variable is the child s score on an intelligence test at the age of 8 Random assignment assigning participants to experimental and control groups by chance thus minimizing preexisting differences between the groups that could affect the dependent variable 9 15 15 The independent variable in this experiment is whether mothers are assigned to an experimental condition in which their children breast feed or to control conditions in which they feed their children formula Random assignment assigning participants to experimental and control groups by chance thus minimizing preexisting differences between the groups that could affect the dependent variable Sometimes its not possible to conduct an experiment For example it isn t possible to assign a child to be male or female for the experiment Other times its unethical to conduct an experiment For example it would be unethical to assign people to polluted or non polluted air for the purpose of seeing the effect of pollution on mental functioning Correlation methods variables Purpose is to observe naturally occurring relationships between variables Correlation coefficient a statistical index 1 to 1 of the relationship between two Scatterplot a graphed cluster of dots each of which represents the values of 2 variables The slope points suggest the direction of the relationship while the amount of scatter suggests the strength of the relationship Correlation and Causation Low self esteem could cause depression Level of depression causes level of self esteem Distressing events or biological predisposition could cause low self esteem and depression MIligram experiments He put up an ad in New Haven for a memory study experiment actually tests learning and punishment teacher is instructed to shock learner when he she make a mistake The shocks get increasingly more severe Severity is labeled Participants believe the final shock is potentially fatal How far would the participants go 65 of the participants would ready to administer the fatal shock Experiment raised troubling questions of ethics in research Research ethics Obtain informed consent Protect them from harm Maintain confidentiality Debrief Biology of the mind Biological Psychology The basic assumption Everything psychological is biological What is the role of the brain in behavior and thinking From the brain and from the brain only arise our pleasures pain etc Hippocrates Phrenology a popular but wrong theory that bumps on the head could reveal mental abilities