SHANK2 and Anxiety: In the classical behavioral assays, Shank2−/− mice were found to show behavioral impairments in anxiety-related behavior (Figure 1B and Figure S3A) and a pronounced hyperactivity phenotype (genotype: p < .0001) (Figure 1C) in the open field test and deficits in learning (p < .0001) and reversal learning (genotype: p < .0001) during the water Y maze compared with their WT littermates (Figure 1E).