I have argued that persons outside of any social context can be scientists. Recently, I watched and listened to a recording of an interview of one philosopher by another, in which the two agreed that science is intrinsically social, that persons outside of social contexts cannot be scientists.
Towards explaining what was wrong with their argument, I'll first explain their argument. One of the very most important things that a scientist ought to do is to look for areas of potential vulnerability in theories, and to test those theories against what evidence may practicably be gathered. And any one researcher is imperfect in his or her ability to find such potential vulnerabilites, in knowledge of existing evidence, and in capacity to collect new evidence. It is often particularly difficult for any one researcher to recognize the unconscious presumptions that inform his or her own theories; exposing the work of one researcher to the scrutiny of other researchers may mean that those presumptions are recognized and challenged.
All right; but, just as any one researcher is imperfect, so are jointly any two researchers, or any three researchers, or any n researchers, for all finite values of n. In fact, I am nearly certain that even an infinite number of scientists would be insufficient to overcome weaknesses across the whole body of theories that these scientists could construct; but, in any case, science is not an unattainable limiting case of behavior. One might instead pick a finite n, and insist that one does not have science until one has n participants engaging in behavior of some sort, but the choice of n would seem to be quite arbitrary; and I'd like to know what one should then call the behavior when there are fewer participants.
As a practical matter, it is far from clear that two people each in isolation engaged in that behavior would continue to engage in that behavior when brought together. Social contexts can promote peculiar forms of irrationality. Historically, a great deal of what has been widely taken to be science by participants and by most observers in wider society has often been grossly unscientific behavior resulting exactly from social pressures. A great deal of what passes for science these days is socially required to conform to consensus, which is to say that social mechanisms protect widely shared presumptions from scrutiny.
 As it happens both one of those philosophers and I referred to Robinson Crusoe as an individual outside of a social context. It was natural for us each independent of the other to reach for the most famous example within our shared cultural context, but it heightened my sense of annoyance.