The US has fallen 16 places in a ranking of the happiest countries because of a 'social crisis'

All things considered, Americans are a fairly happy lot, ranking 14th out of 156 countries in a UN-commissioned report on the world's happiest countries. But that's changing fast. In the past decade, the US has fallen 16 places on the list, one of the biggest drops in the world.

Interestingly, this nosedive toward misery is happening while Americans' per capita GDP is on the rise. This is a stark departure from most of the countries on the list, where having money appears to play a pretty significant role in determining happiness.

So what's driving Americans away from optimism? According to Jeffrey D. Sachs, one of the authors of the report and a special advisor to the United Nations Secretary General, there are four main problems currently plaguing Americans, all of which he says relate intrinsically to health:

• Isolation - Americans are exhibiting less "pro-social" behavior like helping strangers
• Distrust - We're increasingly wearing of one anothers' motives
• Corruption - Americans increasingly see governments and businesses as corrupt
• Rising inequality - The gap between rich and poor is widening

In other words, "America's crisis is, in short, a social crisis, not an economic crisis," Sachs writes.

Looking for happiness 'in all the wrong places'

Unfortunately, Sachs says, the vast majority of US policymakers have focused on economic fixes to these problems, such as raising the rates of economic growth. Instead, we may need to look at solutions that are more sociological in nature - like making sure people have support networks that encourage them to help others.

In an experiment done to gauge how helpful strangers were toward one another, sociologists in the US and Canada scattered more than 7,000 stamped and addressed envelopes in public urban areas like sidewalks, shopping malls, and phone booths between 2001 and 2011 to see whether people who found them would pick them up and put them in a mailbox. The results of this "Lost letter experiment" suggested that during that 10-year period, Americans' helping behavior declined sharply. Amongst Canadians, it rose.

To Sachs, this decline of what he calls "pro-social behavior" is just one indicator of a much larger picture of social collapse in America driven mainly by economic inequality. At the same time, mortality rates amongst middle-aged white Americans are rising, and those deaths have tended to be the result of drug overdose, alcohol poisoning (and diseases related to alcoholism), and suicide.

"What makes the United States case so disturbing and revealing is that it is clearly a social crisis as much as a health crisis," Sachs writes.