“…Unfortunately, just as the term language is often taken to refer to spoken language alone, some have mistakenly believed the critical period applies only to spoken languages. The baseless idea that there is a longer critical period for sign language acquisition has been used to argue that spoken language exposure must be prioritized at the expense of sign language exposure (Sugar & Goldberg, 2015). In contrast, research with the sign-language-as-a-fallback option reveals that deaf adults who did not have access to or achieved age-appropriate mastery of a sign language in childhood do not ever achieve such fluency in their lifetime (Cheng, Halgren, & Mayberry, 2018; Emmorey, 2018; Mayberry, 2010; Mayberry, Chen, Witcher, & Klein, 2011; Mayberry, Davenport, Roth, & Halgren, 2018; Mayberry & Eichen, 1991; Mayberry & Lock, 2003; Newport, 1990; Skotara, Salden, Kügow, Hänel-Faulhaber, & Röder, 2012; Woll, 2018).…”