A behavioral genetic investigation of humor styles and their correlations with the Big-5 personality dimensions Philip A. Vernon a, * , Rod A. Martin a , Julie Aitken Schermer b , Ashley Mackie a a Department of Psychology, University of Western Ontario, London, Ontario, Canada b Management and Organizational Studies, University of Western Ontario, London, Ontario, Canada Received 18 July 2007; received in revised form 26 October 2007; accepted 2 November 2007 Available online 19 December 2007 Abstract Four hundred and fifty six pairs of adult twins completed the Humor Styles Questionnaire – which mea- sures two positive and two negative styles of humor – and the NEO-PI-R, which measures the Big-5 per- sonality traits. Univariate behavioral genetic model-fitting revealed that individual differences in the two positive humor styles (affiliative and self-enhancing) and all five of the Big-5 traits were largely attributable to genetic and nonshared environmental factors, whereas individual differences in the two negative humor styles (self-defeating and aggressive) were largely attributable to shared and nonshared environmental fac- tors. Several significant phenotypic correlations were found between each of the four humor styles and the Big-5, and multivariate behavior genetic analyses revealed that these observed correlations were themselves entirely attributable to genetic and nonshared environmental factors. Ó 2007 Elsevier Ltd. All rights reserved. Keywords: Sense of humor; Personality; Twin study; Behavioral genetics 1. Introduction To what extent are individual differences in sense of humor caused by genetic or environmental factors? Previous behavioral genetic (BG) investigations addressing this question have been quite 0191-8869/$ - see front matter Ó 2007 Elsevier Ltd. All rights reserved. doi:10.1016/j.paid.2007.11.003 * Corresponding author. E-mail address: vernon@uwo.ca (P.A. Vernon). www.elsevier.com/locate/paid Available online at www.sciencedirect.com Personality and Individual Differences 44 (2008) 1116–1125