FMR1 and Anxiety: The Fmr1 knockout (KO) mouse model displays many phenotypes similar to FXS patients, including ASD‐like behaviors (social behavioral deficits, repetitive behavior), hyperactivity, anxiety, and audiogenic seizures, although many of these phenotypes vary depending on the genetic background of the mouse, the age of the mice, and among research groups (Mineur, Sluyter, de Wit, Oostra, & Crusio, 2002; Moy et al., 2009; Pietropaolo, Guilleminot, Martin, D'Amato, & Crusio, 2011; Spencer et al., 2011).