“…Historically, this work has largely relied on subjective self-reports to assess personality, perhaps because researchers previously have questioned the value of collateral informants (e.g., spouse, coworker) in terms of cost, psychometric properties, incremental value (i.e., relative to self-reports), and compliance with completing reports that assess others’ personality traits (for a review, see Vazire, 2006). Importantly, a great deal of research in these areas now indicates that collateral informants’ personality reports (a) can provide cost-efficient, reliable, and valid information about others’ personality traits; (b) can be administered via multiple formats (e.g., in-person clinical assessments, online assessments); and (c) predict variance in external criterion variables over-and-above self-report personality measures (e.g., Balsis, Cooper, & Oltmanns, 2015; Galione & Oltmanns, 2013; Vazire & Mehl, 2008). Yet, with some exceptions (cf.…”