Data mining social group's interests, demographics, and geography

Question

Facebook has Graph Search, which allows finding people by specifying information about them. Facebook, LinkedIn, and Google ads services allow counting the number of people who search certain phrases or fit some characteristics.

Where can I find a kind of reverse of this information, namely, what interests and characteristics a certain group of people has?

For instance, the social group of "teachers" is X years old on average and their most popular interests are "children," "education," and so forth.

There're two groups of possible sources:

• Censuses and other government data (very limited and relatively easy to find)
• Social networks and their subservices, like AdWords, as well as general online data services

And I believe the latter needs a deeper exposition.

Answer 1

There are also academic surveys. Check ICPSR for open-access survey results.

Answer 2

The University of California, Berkley has an interactive form for query social survey data they have compiled ('SDA: Survey Documentation and Analysis'). I don't know if they have a REST or other API interface.

You can find it at this link: http://sda.berkeley.edu/

Their archives are at this link: http://sda.berkeley.edu/archive.htm

The 1972-2010 cumulative General Social Survey (GSS) interactive form is at this link: http://sda.berkeley.edu/cgi-bin/hsda3

Note, they also reference the ICPSR as referred to by the previous answer.