title: So you think you're bulletproof: Development and validation of the Invincibility Belief Index (IBI).
abstract: Risk-taking propensity can be influenced by sensation-seeking traits and self-perceived invincibility. We hypothesized that the latter factor may reflect a stable trait that endures across situations and may influence risk-taking behavior. We developed and validated a 20-item scale, the Invincibility Belief Index (IBI) to measure this construct. The IBI demonstrated good internal consistency and excellent test-retest reliability in the development sample (n = 100) and sustained similar levels of reliability in a cross-validation sample (n = 74). Principal components analysis yielded three orthogonal factors measuring self-perceived impunity (immunity from consequences), boldness/audacity (self-assuredness and competitiveness), and adroitness (mental agility and survival skill). In the prediction of risk taking, IBI scores contributed additional unique variance beyond sensation-seeking scores alone. IBI scores demonstrated convergent and discriminant validity with concurrently administered measures. These preliminary results support the reliability and validity of the IBI as a brief measure of self-perceived vulnerability-invincibility in the face of adversity.
authors.affiliation: Harvard Medical School, Brain Imaging Center, McLean Hospital, 115 Mill Street, Belmont, MA 02478, USA.
authors.forename: William D S
authors.initials: WD
authors.lastname: Killgore
authors.forename: Amanda
authors.initials: A
authors.lastname: Kelley
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Balkin
mesh_terms: D000328:Adult; D003130:Combat Disorders / Q000523:psychology; D003469:Culture; D005260:Female; D006801:Humans; D008297:Male; D008889:Military Personnel / Q000523:psychology*; D008890:Military Psychiatry / Q000379:methods*; D025341:Principal Component Analysis; D011594:Psychometrics; D015203:Reproducibility of Results; D012309:Risk-Taking; D012649:Self Concept; D011795:Surveys and Questionnaires; D014481:United States