I'd like to see the inclusion of data related to the structure and dynamics of the family unit. In the US the family desintegrates as kids are encouraged to leave home as soon as they finish high scool, say, 18 years of age.
This, in a huge number of cultures and countries around the world is an unthinkable attrocity. It isn't uncommon to have children live with their parents until they are ready to form their own families, say, 25 to 30 years of age. Under the stereotypical US culture this is looked down upon to the point of making fun of those still living with their parents.
Having millions of socially unprepared kids go off to try to make it on their own created, in my opinion, a society filled with various levels of dysfunctionalities. People tend to grow up, to some degree, in a "wild" setting where selfishness can become a necessity. In this context it is easy to see how work time can take the place of the social context lost due to having left the nest.
Having grown up and lived in three cultures it is easy for me to remove myself from my US culture and watch it from afar as a visitor from another planet might. Americans are said to seem socially inept and dry from the perspective of other cultures, and this is true. All you have to do is spend six months in Italy or Argentina to undrerstand this. Americans men develop a weird homophobic form of "macho" that is down-right funny from the perspective of other cultures. Hugging, or worst, kissing, another man is frowned upon. Human contact, in general, is just not considered to be "normal". I have lived in cultures where it was quite normal to greet your kids parents with hugs and kisses on the cheeks. In fact, it would be rude to come to a party or gathering and not go around the room kissing everyone, man, woman, kids. Yes, you kiss your friend's wives. School friends do this in high school when they greet each other. Again, unthinkable in the US. In fact, a teacher can get in trouble with the law for greeting a student with a hug and a kiss. Showing affection is alien. Weird.
In general terms, as much as TV shows and commercial try to stereotype this warm southern cowboy culture at the ranch with grandma this is, for the mist part, not the norm. The US family scatters and the kids are left to navigate a very important phase of their lives on their own.
Sorry to harp on this but i do think this is a very important part of the equation and one that explains so much about US society, their behaviors, beliefs, relationships, work and family life. Once you realize that some of these people become politicians that shape US policies and laws it is easy to see where some of our problems might come from.
There are subtle examples of this. For example, let's say you are working with a US friend on a project in their garage. He will use phrases like "give me my hammer" or "it's in my toolbox". In other cultures this becomes "give me the hammer" and "it's in the toolbox". I am convinced this egocentric view of the world is connected to leaving the nest early.
Another example that is particularly bothersome to me are cases where parents pay their children for things that in what I am going to call more socially adjusted societies is simply unthinkable. One of my friends pays his 18 year old kid to go pick him up at the airport. Another pays his kids to help paint the house. My neighbor across the street pays his kid to mow the lawn. Viewed from far more family-centric cultures these woukd be examples of seriously dysfunctional family units. As a teenager I helped my parents in their business. Money was never a part of it. This is simply how a family behaves in other cultures.
Of course I am painting with a wide brush. There are lots of cases of families that behave very differently from this. And, of course, the US has lots of multicultural families, such as mine. Yet I still think that a huge portion of the attitude towards work has to do with a bunch of single people existing "in the wild" and a setting where work can easily become a substitute for the family unit they effectively lost.