Answer:

soc

Answer	Crossword Clue
SOC	One sci.
SOC	Sci. of behavior
SOC	An S in USSR

SOC	Part of ASPCA (abbr.)
SOC	... Sec.
SOC	Part of SSA (abbr.)
SOC	College major (abbr.)
SOC	Assn.
SOC	Org.
SOC	Pt. of SSN
SOC	Humanities course, briefly

SOC	Part of SPCA: Abbr.
SOC	Coll. course
SOC	Eugene Debs's party: Abbr.
SOC	Informal major
SOC	Informal college major
SOC	Part of SDS: Abbr.
SOC	SPCA part: Abbr.
SOC	Religious org., perhaps

SOC	A behavioral sci.
SOC	Humanities maj.
SOC	Part of SSN
SOC	Liberal arts class, for short
SOC	Part of S.P.C.A. (abbr.)
SOC	Pt. of ASCAP
SOC	Part of SSN (abbr.)
SOC	College class, briefly

SOC	Greaser rival in the novel "The Outsiders"
SOC	Liberal arts maj.
SOC	John Birch, for one (abbr.)
SOC	Part of SPCA (abbr.)
SOC	Part of SPCA
SOC	Eugene Debs, e.g.: Abbr.
SOC	Part of ASPCA: Abbr.
SOC	Caseworker's coll. major, perhaps

SOC	Part of ASPCA
SOC	Coll. major
SOC	Part of ASCAP
SOC	The S in ASPCA: Abbr.
SOC	.. Studies (HS class)