Sciences and humanities, one harder than the other?

Wayne Soon has a piece in CNA (originally TODAY) in which he discusses the ongoing efforts to "create a 'thinking school, learning nation'" (I've always disliked that slogan, but whatever...)--focusing on "the 'software' of the education system, especially at the secondary school and pre-university levels." He proposes a "two-pronged approach to facilitate critical thinking skills among young Singaporeans": (1) remove "arbitrary barriers to curriculum choices"; and (2) "introduce subjects that inherently encourage and teach thinking skills"--including social science and humanities subjects such as sociology, religion, politics and economics.

Now I'll leave the readers to make his or her own judgments about these proposals, but in arguing for the first proposals Wayne made some interesting points that bear highlighting. Focusing on the existing "grade criteria for students who want to take a subject combination known as "triple science" in secondary school or who intend to enter the science stream in junior college", Wayne asks three questions:

(a) Is there statistical evidence to prove that higher pre-qualifications are needed to succeed in a "science" stream as compared to in an "arts" stream?

(b) Does this reinforce innate biases that students who study the sciences are "smarter" than those who study the humanities and social sciences? / Does such a policy create the perception among students and parents that those interested in such subjects as history, geography and literature are "less intelligent" as their counterparts taking "hard" sciences?

(c) Ultimately, are subjects such as literature - deemed by many Singaporeans as "fluffy" - easier compared to the hard science of, say, biology?

It would be interesting to see if anyone has any thoughts on these questions. For myself, I don't really have any data on the basis of which (a) can be attacked on any meaningful basis. For (b) and (c), on the other hand, I have to say that there are definitely humanities and social science subjects that are widely considered in some way "less practical" or "useful" than the hard sciences, but nevertheless hard to do well in. I've ran into my share of science or engineering students who confessed that they find the argumentative essays required in arts and humanities courses a considerable challenge to write ("show me an equation; but to argue in words?..."). This might suggest that the perception and bias angle may not be as one sided as might be suggested. But this is mostly at the undergraduate level. Even back in JC days, I though the folks in both the triple sciences and in the hard core humanities were pretty cool (I doubt that you would guess what I took then, unless you knew me).

Any thoughts would be appreciated.

update: just came back from choir practice to notice the extensive comments--thank you everyone for dropping by. In fact, the discussion has so moved Singapore Classics that he "cannot fall asleep", prompting him to blog in response.

I should be clear about something though. I think the original questions as posed by Wayne were meant to be applied to the study of the various subjects at the, say, JC level (I added the university level as well). In other words, the question is whether it is harder to read science as opposed to arts/humanities subjects (at roughly the 'A' levels) and to do well (i.e., get good grades) in them. The discussion seems to have become broader--e.g., the "sciences" or "the arts" in general. Not that I mind, but the difference should be kept in mind. I should have more later but it will be in the comments section. See you there.