A review of the literature on partner personality judgments in both approaches suggests that individuals tend to perceive their partners with both substantial accuracy & a considerable amount of bias

Accuracy and Bias of Trait Judgments in Romantic Relationships. Shanhong Luo and David Watson. In The Oxford Handbook of Accurate Personality Judgment, edited by Tera D. Letzring and Jana S. Spain. Oxford Handbooks Online, Aug 2019. DOI: 10.1093/oxfordhb/9780190912529.013.17

Abstract: This chapter provides a review of recent theoretical developments and empirical evidence regarding accuracy and biases of trait judgments in romantic relationships. Consistent with prior theorizing, personality judgments may be conceptualized to consist of accurate perceptions, systematic biases, and random errors. Two common biases in romantic relationships—positivity bias and similarity bias—are the focus of the chapter. The two major approaches to conceptualizing and assessing accuracy and biases—the variable-centered approach and the person-centered approach—are discussed. A review of the literature on partner personality judgments in both approaches suggests that individuals tend to perceive their partners with both substantial accuracy and a considerable amount of bias. Judges’ personal characteristics, trait properties, and relationship factors may moderate the extent to which the judgments are accurate and biased. Finally, accuracy, positivity bias, and similarity bias all have important positive implications for romantic relationship functioning.

Keywords: accuracy, positivity bias, similarity bias, partner personality judgment, variable-centered approach, person-centered approach, relationship functioning