A cross-lagged panel correlation refers to a study in which two variables are measured once and then again at a later time. By comparing the strength of the relationship between each variable at the first point in time with the other variable at the second point in time, the researcher can determine which variable is the cause and which the effect. A cross-lagged panel correlation provides a way of drawing tentative causal conclusions from a study in which none of the variables is manipulated.
Cross-Lagged Panel Correlation Example
Researchers have used cross-lagged panel correlations to determine whether watching televised violence causes aggression or aggression causes people to prefer viewing television violence. To do so, the researchers measured both the preferred amount of violent television viewed and aggressive behavior of third graders. Ten years later, they again measured the preferred amount of violent television viewed and the aggression of those same people.
Interpreting a Cross-Lagged Panel Correlation
The key to interpreting the results of a cross-lagged panel correlation is to remember that the cause has to come before the effect in time. The researcher can determine which variable influences the other because the variables are measured at each of two different points in time. If both variables are measured simultaneously and only once, causal conclusions cannot be drawn. In the case of a researcher studying television violence and aggression, the researcher cannot be sure whether television violence causes children to become more aggressive, aggressive kids choose to watch more violent shows, or some other factor is causing both aggressive behavior and the viewing of television violence.
To interpret the results of a cross-lagged panel correlation, compare the strength of the relationship between variable A at time 1 and variable B at time 2 with the strength of the relationship between variable B at time 1 and variable A at time 2. In the television violence and aggression example, this means comparing the strength of the relationship between third graders’ aggressiveness and their television viewing preferences 10 years later with the strength of the relationship between third graders’ television viewing preferences and their aggressiveness 10 years later.
If aggressiveness at the first point in time (when the participants were third graders) is related to the amount of violent television viewed at the second point in time (10 years later), but the viewing of violent television in third graders is unrelated to aggressiveness 10 years later, then aggressiveness causes people to prefer watching television violence. If instead television viewing at the first point in time is related to aggressiveness at the second point in time and aggressiveness in third graders is unrelated to their viewing habits 10 years later, then television violence causes aggression.
This particular study was conducted by Leonard D. Eron and his colleagues and published in 1972. They concluded that watching television violence causes aggression; aggression does not cause people to watch more violent television.
Reference:
- Eron, L. D., Huesmann, L. R., Lefkowitz, M. M., & Walder, L. O. (1972). Does television violence cause aggression? American Psychologist, 27, 253-263.
Read More:
- Social Psychology Research Methods