In Academic Year 2013-14 the grades given in the Arts & Humanities Division at Dartmouth were on average 0.29 points higher than in the Science Division on a 4-point grading scale, and in 1977 the difference was 0.25 (you can see the data here). The Social Sciences Division has always been sandwiched between the two, with grades about 0.05 points higher than the Sciences on average over the years. Finally, grades in our Interdisciplinary Programs show more variability over time, but are more similar to the Arts & Humanities than the Sciences and Social Sciences (again, see the data here).
Discussions about grade inflation typically devolve into a shouting match between the Sciences and Humanities, which is completely wrong. Grades in all Divisions and in all departments within them over the past 50 years have risen at nearly identical rates (again, see the data here). Let me say that again: grades in every Science department at Dartmouth are increasing at the same rate as grades in every Social Sciences and Arts & Humanities department and in every Interdisciplinary Program over the past 50 years.
Our committee believes that these differences in grade distributions among academic disciplines are natural. Our effort is decidedly not to equalize grades across Departments or Divisions at all. I think very good educational reasons exist why grades in the Arts & Humanities and Interdisciplinary Programs are higher than in the Sciences and many areas of the Social Sciences. Let me outline some of them here, but in so doing challenge everyone in every discipline to return to more rigorous grading standards. If we do, our students will be better and accomplish more.