Correlational Research Statistical analyses of relationships between variables.

Purpose To identify relationships and assess how well one variable predicts* another. *Meets psychology goal of prediction. It does NOT show cause and effect!

Importance Understanding correlations can help us lead safer and more productive lives. Ex. Correlational studies have repeatedly found high correlations between birth defects and a pregnant mother’s use of alcohol. This kind of information allows us to reliably predict our relative risks and to make informed decisions.

Caution A correlation between two variables does not mean that one variable causes another. Ex. Some media reports about stress and cancer. There is a correlation but does stress cause cancer? What else might contribute?

Types of correlation Or Or Positive (same) Negative (different) Both factors move in the same direction Negative (different) Both factors move in the opposite direction Or Or

Positive Correlation As studying goes up, grades tend to go up!

Positive Correlation As a child’s screaming decreases, so does its mother’s stress level.

Negative Correlation As typing practices increase, errors decrease!

Negative Correlation As stress decreases, health improves (increases)

Zero Correlation There is no relationship Is it true? If you were glasses then you must be smart.

Some potential questions that may be answered with correlational studies Are people who are experiencing severe stress more prone to develop physical illness than people who are not? Are children whose parent(s) have schizophrenia more likely to develop this disorder than other children? When someone needs help, is it more likely that someone would help them if many bystanders are present or just a few?

Quiz: What type of correlation? As a professional bowler’s score goes up, the amount of money he makes goes up. Answer: Positive As a professional golfer’s score goes down, the amount of money he makes goes up. Answer: Negative A researcher finds that students who attend fewer classes get poorer grades. The more ice cream sandwiches someone eats, the greater their ability in math will be Answer: Zero