Abstract
Social behaviors are guided in part by motivational and emotional responses to affective facial expressions. In daily life, facial expressions communicate varying degrees social reward signals (happiness), social threat signals (anger), or social reward-threat conflict signals (co-occurring happiness and anger). Thus, motivational and emotional responses must be sensitive to variations in social signal intensity to effectively guide social behavior. We recently developed a novel social approach-avoidance paradigm (SAAP), which uses morphed facial expressions to assess sensitivity to linear increases in social reward and/or social threat intensity. Prior to large-scale studies validating the test quality of the SAAP, however, it is necessary to first establish the psychometric properties and generalizability of these sensitivity metrics. In Study 1, we independently replicated SAAP task effects and demonstrated that motivational and emotional sensitivity measures exhibit strong psychometric properties and robust individual variability. In Study 2, we demonstrated that more complex social judgements (e.g., trustworthiness) are also sensitive to linear increases in social signal intensity, which differs across judgements. Although future research in larger samples will be needed to establish the test quality of the SAAP, these preliminary findings suggest that the SAAP exhibits adequate psychometric properties to justify this type of large-scale individual differences research.