"The higher divorce rate of couples who previously cohabited compared to those who did not can be explained by different attitudes toward marriage and divorce held by individuals in these two groups." This explanation illustrates:.

Selection effect  

Explanation:

The selection effect or the selection biased is the procedure of distortion in the statistical analysis. collecting in the data from the sample population. It is a threat from out of the four for validity. It shows the result of the test variables. It is a type of conversion rate. It is like collecting the data from the unrepresentative population.  

Thus here the higher diverse report of the divorce of the couples. This is the explanation of the selection bias.  

good question. i'll be looking into that. (this is a joke sir)