Social strain. Social strain was assessed using the Inventory of Negative Social Interactions (INSI) (20). The INSI is a 40-item self-report measure that assesses various types of adverse social experiences
(e.g., being criticized, ignored, and left out). The frequency with which these events have taken place in the preceding month are rated using a 1 to 5 scale, with higher total scores corresponding to greater social strain. The INSI is psychometrically sound [a = 0.92, test–retest reliability = 0.68 (20)]. High internal consistency was found in the present study (a = 0.95).