Objectivity

A colleague recently sent out a link to the Postmodernism Dictionary, which has an entry for the term Objective:

Being objective means to have no bias or distortions; to see things [as] they actually are. It assumes the individual is able to bracket their subjective perspective, biases, and prejudices. Postmodernism, in general, questions the degree to which we can obtain objectivity.

 This is not a good scientific definition of objective; it is, rather, a straw argument, set up as a convenient wall against which to play intellectual ping pong.  Lest I be accused of setting up my own straw postmodernism, let me call your attention to Schultz and Lavenda's textbook, Cultural Anthropology: A Perspective on the Human Condition (Oxford 2012).  This book is written largely from the perspective of non-scientific, postmodern, and interpretivist anthropology.  On page 44, they define objective knowledge as:

Knowledge about reality that is absolute and true.

This is no better.  It reduces the notion of objectivity to a cartoon of itself.  But before I offer something more, er, realistic, let me explain why I am so incensed by these kinds of definitions.

I take anthropology to be a social science.  This is relatively uncontroversial; here at UNF, we're even located in the Social Sciences building (but then, so is the Dean's office!). It is true that we often say that anthropology as a discipline overlaps with the "sciences" and the "humanities" (history, philosophy, world languages, literature, etc.), as if these were normally non-overlapping magisteria, to borrow from Stephen Jay Gould. Scientific method applies here, but not over there.  (I disagree with this divide, I think it's an artifact of a particular cultural history, but that might be another post.)
In any case, the business of the sciences is to develop what I am going to call, after Lett, objective synthetic propositional knowledge. A synthetic proposition is one that's not simply an identity. For example, the proposition "bachelors are unmarried men" is not synthetic, it's analytic, because it's simply a definition.  On the other hand, the proposition "all bachelors are unhappy" is synthetic, it's not a definition but rather a proposition that can be tested and shown to true or false.  I don't want to go any further with these terms; the object of this post is to talk about the notion of objective.
Now, organisms need to be able to acquire knowledge of the world around them to survive, multiply, and prosper.  The knowledge of the world that any organism can acquire and make use of is contingent upon the sort of organism that it is. The contingency is defined by the complexity of the organism's nervous system, and also by the needs of the organism- what it has to "know" to make it through its world.  No organism takes in, processes, and acts on raw data; all organisms "filter" incoming data through their senses, which have been shaped by natural selection.  Frogs, for example, have a visual system that is tuned, by evolution, to make them aware of those things around them that they need to "know" about in order to prosper.  Specifically, frogs' visual system consists of the following sorts of "detectors" (Lieberman 1984: 54-55):

• Edge detectors identify boundaries of objects.
• Bug detectors identify small convex moving objects.
• Event detectors identify sudden movements.
• Dimming detectors identify falling light intensity.
• Blue detectors identify bodies of water.

Having knowledge about these aspects of the world allows frogs to eat, sit by the waterside, and leap into the water when a potential danger appears.  Frogs need to "know" these things (and some others) about the world if they're going to live long enough to reproduce.   This is as true for humans as it is for frogs, although humans, via culture, can manipulate to some degree the contingencies that apply to them.  So, although we have evolved to be able to perceive and respond to narrow (compared to what the Universe makes available) ranges of light and sound, we can create technology that allows us to see and hear beyond the limits of our native visual and auditory systems.  We can do a lot "better" than frogs, in the sense that our visual system allows us to develop more fine-grained visual knowledge of the world around us.  But we, and frogs, are both constrained by our natures; neither of us can develop knowledge about the world that is "absolute and true."
So, back to objectivity. A scientific definition of objectivity as it relates to the construction of propositional knowledge might go something like this (Lett 1997: 46):

[A proposition] is objective in the scientific sense of the term if it is both publicly verifiable and testable.

Example:  I tell students that the Aymara word for 'your house' is utama.  This bit of knowledge is objective not because it's "absolute and true," but because my students can go to Bolivia or Perú, or nowadays even email an Aymara speaker, and ask them how to say 'your house', and the answer should come back utama.  It's publicly verifiable and testable.
Subjective knowledge is about me: The Aymara language sounds beautiful. Not publicly verifiable, not testable.  Objective knowledge is about us, working together, to develop an understanding of the world: The Aymara language is Head-final (heads of phrases follow their complements).  That proposition can be publicly verified and tested.  And that's what science is about.

References
Lett, J. 1997. Science, Reason, and Anthropology: The Principles of Rational Inquiry. Rowman & Littlefield Publishers.
Lieberman, P. 1984. The Biology and Evolution of Language. Cambridge, MA: Harvard University Press.
Schultz, E. and R. Lavenda. 2012.  Cultural Anthropology: A Perspective on the Human Condition. Oxford University Press.