title: Normal variations in personality are associated with coital orgasmic infrequency in heterosexual women: a population-based study.
abstract: BACKGROUND
  As many as 20-30% of women report an inability to orgasm during sexual intercourse. Some female sexual problems have been reported to cluster with psychological and social problems. Underlying personality type may play a role in the development or maintenance of such problems.
  
  
  OBJECTIVE
  The aim of this study was to investigate whether certain domains of personality are associated with female coital orgasmic infrequency. To our knowledge this is the first such study in a large unselected population.
  
  
  METHODS
  A total of 2632 women (mean age 51) from the TwinsUK registry completed questionnaires relating to personality and sexual behavior. Personality domains were assessed using the validated Ten-Item Personality Index (TIPI). Coital orgasmic frequency was measured using a seven-point Likert scale.
  
  
  METHODS
  Using logistic regression, we investigated whether variations in five domains of personality are associated with female coital orgasmic infrequency. Discordant twin analysis was used to verify findings.
  
  
  RESULTS
  Introversion (odds ratio [OR] 2.5, 95% confidence interval [CI] 1.7-3.7), emotional instability (OR 2.0, 95% CI 1.3-3.1), and not being open to new experience (OR 2.4, 95% CI 1.6-3.6) were significantly associated with orgasmic infrequency, whereas indices of agreeableness and conscientiousness were not significantly associated with orgasm frequency.
  
  
  CONCLUSIONS
  Specific personality subtypes appear to be significant risk factors for orgasmic infrequency. Consideration of these behavioral risk factors may need to be incorporated into research into female orgasmic disorder, and possible approaches to its treatment.
authors.affiliation: Twin Research & Genetic Epidemiology Unit, Kings College School of Medicine, London, UK;. Electronic address: juliette.m.harris@kcl.ac.uk.
authors.forename: Juliette M
authors.initials: JM
authors.lastname: Harris
authors.affiliation: Twin Research & Genetic Epidemiology Unit, Kings College School of Medicine, London, UK.
authors.forename: Lynn F
authors.initials: LF
authors.lastname: Cherkas
authors.affiliation: Twin Research & Genetic Epidemiology Unit, Kings College School of Medicine, London, UK.
authors.forename: Bernet S
authors.initials: BS
authors.lastname: Kato
authors.affiliation: The Kinsey Institute for Research in Sex, Gender and Reproduction, Bloomington, IN, USA.
authors.forename: Julia R
authors.initials: JR
authors.lastname: Heiman
authors.affiliation: Twin Research & Genetic Epidemiology Unit, Kings College School of Medicine, London, UK.
authors.forename: Tim D
authors.initials: TD
authors.lastname: Spector
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003075:Coitus; D005260:Female; D020010:Heterosexuality; D006801:Humans; D008875:Middle Aged; D009948:Orgasm; D010551:Personality; D012042:Registries; D012307:Risk Factors; D020018:Sexual Dysfunctions, Psychological / Q000523:psychology*; D014427:Twins