In the 1970s,a Number of Studies Suggested That Over the Course

Multiple Choice

In the 1970s,a number of studies suggested that over the course of a long marriage,spouses' relationship satisfaction generally followed a U-shaped curve: first declining,then remaining stable,and then increasing (presumably after children left home) .In the 1990s,new research proved this idea wrong.Generally,marital satisfaction declines throughout the course of marriage.What was the difference between the earlier and the later research?

A) The early research was correlational,and the later research was experimental.
B) The early research suffered from attrition bias,and the later research did not.
C) The early research examined only American couples,and the later research examined cross-cultural samples.
D) The early research was cross-sectional,and the later research was longitudinal.