Social scientists and literary scholars have claimed that many things are social constructions or social constructs, or that they have been socially constructed.
The term "social construction"
The first book with "social construction" in its title was Peter L. Berger and Thomas Luckmann's The Social Construction of Reality, first published in 1966. Since then, the term found its way into the mainstream of the social sciences. For a description of key concepts, see social constructionism and deconstruction.
Philosopher and historian of science Ian Hacking (1999, p. 18) claims that the term is also used where its usage isn't meaningful. As an example, he relates that Rom Harré's publisher insisted that Harré change the title of one of his works from The Social Production of Emotions to The Social Construction of the Emotions (Wikipedia's emphasis) since more copies would sell under the new title. "Social construction" may also sometimes be used primarily to make friends or enemies; as Hacking (1999, p. vii) says, "The phrase has become code. If you use it favorably, you deem yourself rather radical. If you trash the phrase, you declare that you are rational, reasonable, and respectable".
Even if "social construction" has become something of a buzzword, Berger and Luckmann's book has influenced the social sciences on a deep level. They have described how the invisible but mighty borders and sets of rules of society are created, changed, institutionalized and transmitted to the next generation.
What entails a social construct?
Different authors have different views on what being a social construct entails. Nonetheless, following, Gross and Levitt, we can classify many views into one of two roughly defined camps: "weak" and "strong" social constructionism.
Weak social constructionism
Linguist Steven Pinker (2002, p. 202) writes that "some categories really are social constructions: they exist only because people tacitly agree to act as if they exist. Examples include money, tenure, citizenship, decorations for bravery, and the presidency of the United States."
In a similar vein, Stanley Fish (Fish 1996) has suggested that the baseball's "balls and strikes" are social constructions (Hacking 1999, pp. 29-31).
Both Hacking(?) and Pinker agree that the sorts of objects indicated here can be described as part of what John Searle calls "social reality". In particular, they are, in Searle's terms, ontologically subjective but epistemologically objective. Informally, they require human practices to sustain their existence, but they have an effect that is (basically) universally agreed upon. The disagreement lies in whether this category should be called "socially constructed". Hacking (1997) argues that it should not. Furthermore, it is not clear that authors who write "social construction" analyses ever mean "social construction" in Pinker's sense. If they never do, then Pinker (probably among others) has misunderstood the point of a social construction argument.
People who write social construction analyses are sometimes called social constructionists. They are not the only ones, however. To the annoyance of Hacking (1999, p. 65), some people count all scholars in the fields known as Sociology of Scientific Knowledge, Science and Technology Studies, and Social Studies of Science as constructionists, even those who do not discuss science in the terms described above.
Strong social constructionism
"Science is a highly elaborated set of conventions brought forth by one particular culture (our own) in the circumstances of one particular historical period; thus it is not, as the standard view would have it, a body of knowledge and testable conjecture concerning the real world. It is a discourse, devised by and for one specialized interpretive community, under terms created by the complex met of social circumstance, political opinion, economic incentive and ideological climate that constitutes the ineluctable human environment of the scientist. Thus, orthodox science is but one discursive community among the many that now exist and that have existed historically. Consequently its truth claims are irreducibly self-referential, in that they can be upheld only by appeal to the standards that define the scientific community and distinguish it from other social formations." (Gross and Levitt, Higher Superstition)
Scientists and historians generally do not attempt to refute the idea that most (or all) of the world is a social construction. The entire idea is widely dismissed as a disguised version of solipsism. Some literary critics do think it is worth refuting this position. A few attempts have been made to refute the idea that everything is socially constructed. However, it is not clear that anyone has seriously claimed that everything is a social construct. (Hacking 1999, pp. 24-25). Consider The Social Construction of Reality. In the introduction, Berger and Luckmann clarify that they are not investigating "reality" in any deep philosophical sense, only what the common man takes as real on a day-to-day basis.
What kind of analyses are "social construction" analyses?
This is a difficult question to answer; "social construction" may mean many things to many people. Hacking, having examined a wide range of books and articles with titles of the form "The social construction of __________" or "Constructing __________", argues that when something (let's call it X) is said to be "socially constructed", this is shorthand for at least the following two claims:
- (0) In the present state of affairs, X is taken for granted; X appears to be inevitable. (Hacking 1999, p. 12)
- (1) X need not have existed, or need not be at all as it is. X, or X as it is at present, is not determined by the nature of things; it is not inevitable. (Hacking 1999, p. 6. Emphasis added.) 
Hacking adds that the following claims are also often, though not always, implied by the use of the phrase "social construction":
- (2) X is quite bad as it is.
- (3) We would be much better off if X were done away with, or at least radically transformed. (Hacking 1999, p. 6)
Thus a claim that gender is socially constructed probably means that gender, as currently understood, is not an inevitable result of biology, but highly contingent on social and historical processes. In addition, depending on who is making the claim, it may mean that our current understanding of gender is harmful, and should be modified or eliminated, to the extent possible.
According to Hacking, "social construction" claims are not always clear about exactly what isn't "inevitable", or exactly what "should be done away with." Consider a hypothetical claim that quarks are "socially constructed". On one reading, this means that quarks themselves are not "inevitable" or "determined by the nature of things." On another reading, this means that our idea (or conceptualization, or understanding) of quarks is not "inevitable" or "determined by the nature of things"  Hacking is much more sympathetic to the second reading than the first (Hacking 1999, pp. 68-70). Furthermore, he argues that, if the second reading is taken, there need not always be a conflict between saying that quarks are "socially constructed" and saying that they are "real" (Hacking 1999, pp. 29-30).
As we step from the physical word to the world of human beings, "social construction" analyses can become more complex. Hacking briefly examines Helène Moussa’s analysis of the social construction of "women refugees" (Hacking 1999, pp. 9-10). According to him, Moussa's argument has several pieces, some of which may be implicit:
- Canadian citizens' idea of "the woman refugee" is not inevitable, but historically contingent. (Thus the idea or category "the woman refugee" can be said to be "socially constructed".)
- Women coming to Canada to seek asylum are profoundly affected by the category of "the woman refugee". Among other things, if a women does not "count" as a "woman refugee" according to the law, she may be deported, and forced to return to very difficult conditions in her homeland.
- Such women may modify their behavior, and perhaps even their attitudes towards themselves, in order to gain the benefits of being classified as a "woman refugee".
Hacking suggests that this third part of the analysis, the "interaction" between a socially constructed category and the individuals that are actually or potentially included in that category, is present in many "social construction" analyses involving types of human beings.
 Numbering begins with 0 for consistency with Hacking's usage.
 The distinction between "quarks themselves" and "our idea (or conceptualization, or understanding) of quarks" will undoubtedly trouble some with a philosophical bent. Hacking's distinction is based on an intuitive metaphysics, with a split between things out in the world, on one hand, and ideas thereof in our minds, on the other. Hacking is less advocating a serious, particular metaphysics than suggesting a useful way to analyze claims about "social construction". See (Hacking 1999, pp. 21-24).
Reference and further reading
- Peter L. Berger and Thomas Luckmann: The Social Construction of Reality. New York: Doubleday, 1966.
- Ian Hacking (1999). The Social Construction of What?. Harvard University Press: 2001.
- Ian Hacking (1997). John Searle's building blocks. History of the Human Sciences.
- Steven Pinker (2002). The Blank Slate: The Modern Denial of Human nature. Viking Penguin.