What is a primary characteristic of positive correlation?

A primary characteristic of positive correlation is that both variables trend in the same direction. When one variable increases, the other variable also tends to increase; conversely, when one variable decreases, the other variable typically decreases as well. This relationship indicates a direct association between the two variables, meaning that changes in one variable are reflected in the same direction by changes in the other.

In contrast, the other options describe different types of relationships. For instance, one option suggests that one variable increases while the other remains constant, indicating no correlation. Another option describes a scenario where one variable decreases while the other stays unchanged, again reflecting a lack of correlation. Finally, stating that variables have no predictable relationship describes a situation of zero correlation or randomness instead of the consistent directional relationship that defines a positive correlation. Understanding positive correlation is vital in psychology, as it often helps researchers identify trends and patterns in behavior or responses among populations.