The Phi Beta Kappa Society (PBK), the nation’s oldest academic honor society, held its MIT induction ceremony this year admitting 115 graduating seniors into the MIT chapter, Xi of Massachusetts.PBK, founded in 1776 at the College of William and Mary, honors the nation’s most outstanding undergraduate students for excellence in the liberal arts, which includes the humanities and the natural and social science fields. In addition to extraordinary students with liberal arts majors, PBK honors engineering students who have excelled in extensive coursework in the liberal arts.Only 10 percent of higher…