In Japan, it’s known as retired husband syndrome: older couples whose kids are no longer at home decide to throw a fire blanket over the last few embers of their marriage and snuff it out rather than let it expire along with them. Though overall U.S. divorce rates have declined since their peak in the 1980s, the divorce rate among the 50-plus crowd has risen to its highest level on record. In 1990, only 1 in 10 couples seeking a divorce were 50 or older; by 2009, the number was roughly 1 in 4. That year, the poster couple was Al and Tipper Gore, who separated after more than 40 years of marriage. This year it was Hollywood’s turn; Danny DeVito and Rhea Perlman, married a whisker longer than 30 years, announced their separation in October.