Our cultural attitudes about marriage, living together without getting married and having children have been shifting dramatically. Look at these rather amazing findings about the world we are now living in.

As recently reported in the New York Times by David Brooks, in 1957, 57 percent of those surveyed said that they believed adults were “immoral” or “neurotic” if they remained single. Today, 45 percent of all households consist of single adults, according to the 2008 census. In 1990, almost two-thirds of Americans said that children were very important to a successful marriage. Today, only 41 percent say that. There are now more houses that have dogs than have children.

A generation or two ago, it was considered shameful for adults to have children unless they were married. Today, more than half of all births born to women under 30 occur outside of marriage. There are now more households that consist of single adults than there are married-with-children households. In Manhattan, roughly half of all residences are single households. In Denver, Washington DC and Atlanta, more than 40 percent of residential units are single households.

In the late 1960’s, 10 percent of couples lived together before marriage. Today, 60 percent of couples live together first, and an increasing number of couples are living together and choosing not to get married. The age in which people first marry have now hit record highs: 28.7 years for men, and 26.5 for women. The divorce rate today for people 50-64 has doubled since 1990, and tripled for those 65 and above.

And just in case you thought this was strictly an American phenomenon, 30 percent of German women of child-bearing age say they do not intend to have children. The number of marriages in Spain has declined by 37 percent from 1975 to today. In a 2011 survey of Taiwanese women, a majority of women of child-bearing age said that they did not want children. Fertility rates in Brazil have dropped from 4.3 babies per woman to 1.9 babies in the last 35 years. And of course there is now same-sex marriage, which has been legalized in the Netherlands, Belgium, Spain, Canada, South Africa, Norway, Sweden, Portugal, Iceland, Argentina, Denmark, Mexico and 9 states in the US.

It is clear that attitudes are changing rapidly about marriage and the rules that govern intimate relationships, and they’re changing throughout much of the world. In attempting to interpret this data, let me offer a few observations. First, people are increasingly less tolerant and less willing to remain in unsatisfactory or unhappy marriages, and today people tend to be more enlightened about what a good marriage is. Fewer and fewer people are willing to feel trapped in an unhappy relationship indefinitely.

Second, societal and religious “moral” codes of “right vs. wrong” behavior have become less honored by an increasing number of people, spanning a variety of different cultures and religions. Third, there is an increasing interest in alternative lifestyle choices, and a far greater willingness to live outside of traditional norms.

Fourth, there is an unmistakable acknowledgement that marriage is hard to successfully traverse over a long period of time. (Last year, several lawmakers in Mexico City proposed the creation of renewable marriage contracts, where you would in essence get married for a couple of years, and then you would have the option of renewing the contract or opting out. The law was not passed, but the fact that it was proposed in Mexico, an overwhelmingly Catholic country, tells us that people are seriously reconsidering the wisdom of the marriage contract as we have always known it.)

The vows that we take: “Till death do us part,” come from the middle ages, where the average life span was 30 years of age. Today the average life span is approximately 80 for women and 75 for men. (In New Zealand, it is 78 for men and 82 for women. In Japan, it is 79 for men and 86 for women.) So now, when you’re 40 and you’re looking at the face across the breakfast table, you can pause and ask: “Another 40 years of you? Another 40 years of this?”

You can see why “Till death do us part” didn’t have the same meaning that it does today, and it’s a much bigger challenge than it used to be.

That being said, when a marriage works today, it works better than it has ever worked in the past. There is more communication, more shared decision making, more equality, more respect, less violence, more closeness and greater connection for an ever larger number of couples spanning different cultures and continents, and encompassing an ever wider range of lifestyle choices.