understanding correlations
Handout Master 1.4
Understanding Correlations
Correlational studies show relationships between variables. If high scores on one variable predict high scores on the other variable, the correlation is positive. If high scores on one variable predict low scores on the other variable, the correlation is negative.
Showing that two variables are related does not justify claiming that a causal relationship exists. There may be a causal relationship, but other explanations usually exist. For example, the variables may be related because both have a causal relationship with a third variable.
For each of the correlational studies described below, decide whether the correlation is positive or negative and give two alternative explanations for each finding.
1. A study of married couples showed that the longer they had been married, the more similar their opinions on social and political issues were.
Positive or negative? - POSITIVE
Explanation 1: They could have dealt with similar problems and issues in the past to make them whom they are now which makes them more compatible for each other.
Explanation 2: Couples married for a longer are more similar and may lead to a longer future together.
2. An intelligence test was given to all the children in an orphanage. The results showed that the longer children had lived in the orphanage, the lower their IQ scores.
Positive or negative?
NEGATIVE
Explanation 1: Being inside the orphanage can shelter the individuals intellect making the education development .
Explanation 2:The Smart kids that were in the orphanage could more likely be adopted than a kid proved to have an lower iq.
3. In a study of American cities, a relationship was found between the number of violent crimes and the number of stores selling violence-depicting pornography.
Positive or negative?
POSITIVE
Explanation 1:The more that stores was selling of the pornography stimulated the crime rate making it increase.
Understanding Correlations
Correlational studies show relationships between variables. If high scores on one variable predict high scores on the other variable, the correlation is positive. If high scores on one variable predict low scores on the other variable, the correlation is negative.
Showing that two variables are related does not justify claiming that a causal relationship exists. There may be a causal relationship, but other explanations usually exist. For example, the variables may be related because both have a causal relationship with a third variable.
For each of the correlational studies described below, decide whether the correlation is positive or negative and give two alternative explanations for each finding.
1. A study of married couples showed that the longer they had been married, the more similar their opinions on social and political issues were.
Positive or negative? - POSITIVE
Explanation 1: They could have dealt with similar problems and issues in the past to make them whom they are now which makes them more compatible for each other.
Explanation 2: Couples married for a longer are more similar and may lead to a longer future together.
2. An intelligence test was given to all the children in an orphanage. The results showed that the longer children had lived in the orphanage, the lower their IQ scores.
Positive or negative?
NEGATIVE
Explanation 1: Being inside the orphanage can shelter the individuals intellect making the education development .
Explanation 2:The Smart kids that were in the orphanage could more likely be adopted than a kid proved to have an lower iq.
3. In a study of American cities, a relationship was found between the number of violent crimes and the number of stores selling violence-depicting pornography.
Positive or negative?
POSITIVE
Explanation 1:The more that stores was selling of the pornography stimulated the crime rate making it increase.