But what about social pains and pleasures? We often speak poetically and metaphorically about the pain of experiencing envy, or the pleasure of donating to a favorite charity. Turns out, such talk need not be considered quite so metaphorical.
A study published in the 13 February 2009 issue of Science magazine by H. Takahashi and collaborators has investigated what happens in the brain when we experience those socially triggered feelings of envy or self-satisfaction. The results are rather stunning, if perfectly logical in hindsight: the researchers found that the same neural circuitry that is involved in the generation of physical pain and pleasure is also in charge of generating the analogous reactions in response to apparently more abstract situations.
For instance, people experiencing envy because of another's success activate the pain circuitry of their brains, and when that person is befallen by misfortune, the reward neurocircuitry is activated because we feel delighted. On the more positive side, making a donation to a charity not only stimulates the reward system, but it does so more intensely than when we receive money ourselves.
Biologically this makes sense because the human species' survival and reproduction -- those golden standards of evolution -- depend as much on social interactions as on interactions with the physical environment. Cutting yourself may turn out to be lethal, but so may be getting on the wrong side of enough people in the group which you depend upon for long term sustenance. Not finding enough sugary and fatty foods is certainly bad news, but so is not finding a mate willing and able to copulate and have progeny with you (evolutionarily speaking).
I find the implications of the new research, however, to be particularly compelling for the continuing philosophical debate about the nature of emotions and the primacy of subjective experience. Some philosophers, usually of the continental tradition (particularly phenomenologists) seem to feel a particular delight (I wonder by which circuits in their brains ) in pointing out that science is intrinsically limited because it will never be able to tell us anything about first person, subjective experience of the world. Not only that, but science -- in these people's minds -- cannot even satisfactorily account for the very generation of subjective experiences (so called "qualia"), such as pain, or color.
If the point is simply that science can at best hope to describe and explain the neural circuitry that makes subjective experience possible, but that only a subject can "feel" what it is like -- in the title of a famous paper by Thomas Nagel -- to be a bat (or anything else for that matter), this seems to be rather trivial and not that interesting (although phenomenologists do make a big deal of it). The objective of science is to provide a mechanistic account of feelings, not to feel the emotions themselves. So it isn't really a failure of science at all, but rather a misconception on the part of some philosophers as to what cognitive research is attempting to do.
But reading some of the philosophical literature, one does get the impression that the science skeptics are after something more fundamental: they seem to be claiming that there is an uncanny, non-materialistic nature to subjective experiences, which therefore not only cannot be "felt" through a third party approach, but cannot even be adequately explained mechanistically. From there to the classic position of mind-matter dualism the step is short indeed.
Yet, research like the one by Takahashi and colleagues continuously chips away at a non-materialistic view of human emotions and subjective experience. We know quite a bit now about how the sensation of color, a staple of the qualia debate, actually originates. To insist that one still needs to personally experience what color feels like is -- again -- entirely beside the point: we know the neural basis of the phenomenon, we have a good understanding of the chemicals involved and how they react to light of different wavelengths, and we even have a pretty good idea of why color vision evolved to begin with. What else does one want in order to acknowledge that we do have a good scientific explanation of color? We are not quite yet in the same explanatory position concerning complex emotions like social pains and pleasures, but the study published in Science is a good step in that direction.
This, I hasten to clarify, is not a tale of science vs. philosophy, where the latter inevitably retreats in the wake of a steady advance of the former. Rather, it is a question of what happens when philosophy unnecessarily pits itself against science. Instead of reveling in pointing out the alleged limitations of science as an explanatory enterprise of natural processes, philosophers should concentrate on how a better understanding of science can help them to deal more effectively with truly philosophical questions. For instance, if we accept that certain social actions are related to neural pains and pleasures because of evolutionary history, what does that tell us about the foundations of our moral reasoning, and how can philosophy help us transcend a naturalistic morality that may have been all right in Pleistocene times, but is clearly inadequate to navigate the complex global society of the 21st century?