The seven-year itch is a psychological term that suggests that happiness in a relationship declines after around year seven of a marriage.
The seven-year itch can be analyzed quantitatively. Divorce rates show a trend in couples that, on average, divorce around seven years. Statistics show that there is a low risk of separation during the first months of marriage. After the “honeymoon” months, divorce rates start to increase. Most married couples experience a gradual decline in the quality of their marriage; in recent years around the fourth year of marriage. Around the seventh year, tensions rise to a point that couples either divorce or adapt to their partner.
In samples taken from the National Center for Health Statistics, there proves to be an average median duration of marriage across time. In 1922 the median duration of marriage that ended in divorce was 6.6. In 1974 the median duration was 7.5. In 1990 the median duration was 7.2. While these can fluctuate from year to year, the averages stay relatively close to the seven year mark.