Social science studies human behaviour, hence the question for a philosopher would be what the definition of being a human is? Where do we draw the line of human and non-human? The natural scientific answer would be based on Carl von Linné who classified the human species as “homo sapiens”. But are biological features such as bipedal locomotion and a larger brain than other primates enough to explain what it means to be human?
This might be recognized as the metaphysical expression of the mind-body problem, regarding the relation between consciousness and brain as expressed by Descartes (see among others Treanor, 2006); Can the two be distinguished from one another, is one a cause of the other, where do they meet, can we know for sure both exist? These questions are far from being resolved, however a naturalist would argue that the mental is caused by the physical, or perhaps “faked” by physics as Rosenberg (2013) puts it. But still, we cannot that easily dismiss consciousness, something even creatures appears to have although to a lesser extent. Humans still not only think and feel as a foundation for their own actions, they also are aware that others do the same.
Then which level of consciousness, self-conceptualization, does one need to have in order to be human? If it is a higher level of intelligence, as argued by Roth and Dicke (2005), then which level of intelligence, since there seems to be individual variations? And turning it around, can there be certain traits that we can loose and still be human? There is also a moral dimension to humanity, where the deontological approach seems to be the dominant in society in that every human has certain fundamental rights and value, which are superior to others. These rights are increasingly being applied also to animals leading to veganism and animal rights-movements. It becomes clear that defining exactly what it means to be human is complex and that it looks to go beyond what it means on a natural level. Naturalistic method seems to be incapable in answering these questions, despite its capability in answering such complicated matters as the Higgs boson holding the world together. But why not give the naturalists the benefit of the doubt, perhaps neuroscience is the Holy Grail in answering these questions, and will be able to do so in the future.