A simple regression is conducted using a sample from one population (e.g., girls) and the standardized regression coefficient is estimated to be= 0.4. The same regression analysis is conducted using a sample from a different population (e.g., boys) and the standardized regression coefficient is also estimated to be= 0.4. On the basis of this result showing homogeneity of standardized slope, the researcher decides to pool the data from the two samples.

Under what circumstances would we expect the standardized slope of the combined sample to be stronger than 0.4, if ever? Weaker than 0.4, if ever? The same as 0.4, if ever? Explain your answer in detail.