Througout the Western world the divorce rate generally climbed in 1960s and 1970s, then leveled off in the 1980s. This reflects the passage of the post - World War II baby boom generation through its twenties, the decade of life when people are most likely to get divorced.
One key cause is a change in values. More people today evidently feel that commitment to staying married and raising children together is less important than personal fulfillment and happiness. Other factors contributing to the high divorce rate include the increased economic independence of women as more of them work, and the declining influence of family, ethnic, and religious ties that reinforce the commitment to marriage.
Along with these social changes, the divorce laws have been greatly modified. They make it much easier to dissolve a marriage; often mutual consent is all that is legally required.