... With the breakthrough in conceptualizing this construct and the aid of this highly valid and reliable instrument, researchers have been able to conduct systematic investigations (e.g., MacIntyre and Gardner, 1991;Phillips, 1992;Aida, 1994;Saito and Samimy, 1996;Cheng et al., 1999;Yan and Detaramani, 2008;Liu and Li, 2019), and a consistent negative correlation has been found between FLA and achievement. The adverse effect of FLA on language achievement has been confirmed by studies on the learning of different languages (e.g., Kitano, 2001;Yan and Wang, 2001;Kondo and Yang, 2004;Matsuda and Gobel, 2004;Elkhafaifi, 2005;Frantzen and Magnan, 2005), and various aspects of language proficiencies (e.g., Oh, 1992;Cheng et al., 1999;Saito et al., 1999;Kim, 2000;Sellers, 2000;Argaman and Abu-Rabia, 2002;Elkhafaifi, 2005;Liu, 2006). ...