Must Scientific Knowledge Be Considered Relative?

In the late nineteenth century, Nietzsche wrote: "Against that positivism which stops before phenomena, saying 'there are only facts,' I should say: no, it is precisely facts that do not exist, only interpretations."

Abstract
Biology is seen not merely as a privileged oppressor of women but as a co-victim of masculinist social assumptions. We see feminist critique as one of the normative controls that any scientist must perform whenever analyzing data, and we seek to demonstrate what has happened when this control has not been utilized. Narratives of fertilization and sex determination traditionally have been modeled on the cultural patterns of male/female interaction, leading to gender associations being placed on cells and their components. We also find that when gender biases are controlled, new perceptions of these intracellular and extracellular relationships emerge.

Social Constructivism

One outcome of the historical turn in the philosophy of science and its emphasis on scientific practice was a focus on the complex social interactions that inevitably surround and infuse the generation of scientific knowledge. Relations between experts, their students, and the public, collaboration and competition between individuals and institutions, and social, economic, and political contexts, became the subjects of an approach to studying the sciences known as the sociology of scientific knowledge, or SSK. Though in theory, a commitment to studying the sciences from a sociological perspective is interpretable in such a way as to be neutral with respect to realism, in practice, most accounts of science inspired by SSK are implicitly or explicitly antirealist. This antirealism in practice stems from the common suggestion that once one appreciates the role that social factors (using this as a generic term for the sorts of interactions and contexts indicated above) play in the production of scientific knowledge, a philosophical commitment to some form of “social constructivism” is inescapable, and this latter commitment is inconsistent with various aspects of realism.

The term ‘social construction’ refers to any knowledge-generating process in which what counts as a fact is substantively determined by social factors, and in which different social factors would likely generate facts that are inconsistent with what is actually produced. The important implication here is thus a counterfactual claim about the dependence of facts on social factors. There are numerous ways in which social determinants may be consistent with realism; for example, social factors might determine the directions and methodologies of research permitted, encouraged, and funded, but this by itself need not undermine a realist attitude with respect to the outputs of scientific work. Often, however, work in SSK takes the form of case studies that aim to demonstrate how particular decisions affecting scientific work were influenced by social factors which, had they been different, would have facilitated results that are inconsistent with those ultimately accepted as scientific fact.

From: Chakravartty, Anjan, "Scientific Realism", The Stanford Encyclopedia of Philosophy

Though in theory, a commitment to studying the sciences from a sociological perspective is interpretable in such a way as to be neutral with respect to realism, in practice, most accounts of science inspired by SSK are implicitly or explicitly antirealist. This antirealism in practice stems from the common suggestion that once one appreciates the role that social factors (using this as a generic term for the sorts of interactions and contexts indicated above) play in the production of scientific knowledge, a philosophical commitment to some form of “social constructivism” is inescapable, and this latter commitment is inconsistent with various aspects of realism.

That virtually all science is socially constructed is an important truth, but from that it is does not follow that all social constructions are scientific. But I've never heard any social theorist assert that they are.