I noticed on the Bowdoin admissions website under Test Optional Policy that they now superscore the ACT. This change I believe has been very recent as during the tour a few months ago they said specifically that they did not Superscore the ACT. Here is the information straight from the website:
http://www.bowdoin.edu/admissions/apply/testing-policy.shtml
Superscoring
Bowdoin will “superscore” the SAT. That is, the admissions committee will consider the highest Critical Reading, Math, and Writing Scores submitted by an applicant, irrespective of test date.
Bowdoin will NOT combine results from Redesigned and pre-Redesign SAT exams to create a new total score. We will superscore Redesigned and pre-Redesign results separately, considering the highest section and total scores submitted from either set of results.
Bowdoin superscores the ACT. The admissions committee will consider the highest submitted Composite score and subsection scores, and will also recalculate a new Composite score from subsection scores earned on different test dates.