Each participant nominated two peers who knew them well. We only sought to obtain data from one peer, but obtained two contacts for cases in which the first peer did not participate. As in some other past studies (e.g., Marsh & O’Neill, 1984), peers were asked to complete the questionnaires “as if you were your friend who is completing the questionnaires about [themselves].” Each peer completed neuroticism measures: the Big 5-N, the IPIP-N, and the BIS. They also completed a demographic questionnaire that assessed how long they had known the participant, frequency of contact, and confidence for their ratings. Internal consistency for peer measures ranged from .76 to .91. Descriptive statistics indicated that, on average, peers had known participants for 72 months (SD=55), were in contact with the participant 5.3 days per week (SD=1.8), and had high levels of confidence in their ratings of participants’ personalities (mean=5.4 on a 0-7 scale, SD=1.3). Peers received $15 for participating. Peer data were collected between 3 and 22 months (median=6) after participants completed questionnaires.
