We assess how "implicit" selections based on non-cognitive abilities may have changed in the context of the great higher education expansion in China, applying the classic supply-demand framework and utilizing the Big Five personality model. Using the Chinese General Social Survey (CGSS) data from 2012, difference-in-difference (DID), difference-in-difference-in-difference (DDD) and descriptive analyses establish the following three major findings. First, from the generation entering college before the expansion--post-70s--to the generation entering college after the expansion--post-80s and post-90s--implicit selections in higher education based on personality have weakened with the increased supply of higher education opportunities. Second, selections have significantly weakened in terms of the openness dimension of personality, yet there is some evidence that selections have strengthened in terms of conscientiousness. This reflects that open-mindedness has become a relatively higher supply trait and conscientiousness has become a relatively lower supply trait among members of the post-90s generation. Third, selections have weakened only on the openness dimension for males, but on multiple dimensions beginning with agreeableness for females, reflecting a greatly increased supply of higher education opportunities for females with this dominant trait. The finding on strengthened selections based on conscientiousness has important implications for what and how to educate today's college students.