Which is more revealing: the mundane action we repeat every day, or our response to an extraordinary event that will never come again? Anyone familiar with the work of T.C. Boyle already knows his answer: crisis all the way. In “Wild Child,’’ his exhilarating new collection of short stories, Boyle captures characters facing a range of critical turning points. Some of these moments are quiet: An unexpected emotional connection is made in a rundown recording studio (“Three Quarters of the Way to Hell”); a college graduate wonders whether she should accept a menial dog-sitting job (“Admiral”). Others are more obviously dramatic: A woman encounters an escaped tiger in her suburban garden (“Question 62”); a Venezuelan baseball player discovers his mother has been kidnapped (“The Unlucky Mother of Aquiles Maldonado”). In Boyle’s world, they all have the potential to become peak experiences.