Anorgasmia is significantly more common in women than in men, which has been attributed to the lack of sex education with regard to womens bodies, especially in sex-negative cultures, such as clitoral stimulation usually being key for women to orgasm.Approximately 25% of women report difficulties with orgasm, 10% of women have never had an orgasm, and 40% or 40–50% have either complained about sexual dissatisfaction or experienced difficulty becoming sexually aroused at some point in their lives. A 1994 study by Laumann et al. found that 75.0% of men and 28.6% of women always had orgasms with their spouse, while 40.2% of men and 79.7% of women thought their spouse always orgasmed during sex. These rates were different in non-marital straight relationships (cohabitational, long-term and short-term heterosexual relationships), with rates increasing to 80.5% for men and 43.0% for women orgasming during sex with their short-term partners, and 69.3% for men and 82.6% for women thinking their short-term partners always orgasmed. Women are much more likely to be nearly always or always orgasmic when alone than with a partner. However, in a 1996 study by Davis et al., 62% of women in a partnered relationship said they were satisfied with the frequency/consistency of their orgasms.
His research indicates that "[a] prominent and sharply raised lip tubercle has been associated with greater odds (odds ratio = 12.3) of ever having a vaginal orgasm, and also with greater past month vaginal orgasm consistency (an effect driven by the women who never had a vaginal orgasm), than less prominent lip tubercle categories." However, lip tubercle was not associated with social desirability responding, or with orgasm triggered by masturbation during penile-vaginal sex, solitary or partner clitoral or vaginal masturbation, vibrator, or cunnilingus.An empirical study carried out in 2008 provides evidence for Freuds implied link between inability to have a vaginal orgasm and psychosexual immaturity. In the study, women reported their past month frequency of different sexual behaviors and corresponding orgasm rates and completed the Defense Style Questionnaire (DSQ-40), which is associated with various psychopathologies. The study concluded that a "vaginal orgasm was associated with less somatization, dissociation, displacement, autistic fantasy, devaluation, and isolation of affect." Moreover, "vaginally anorgasmic women had immature defenses scores comparable to those of established (depression, social anxiety disorder, panic disorder, and obsessive–compulsive disorder) outpatient psychiatric groups." In the study, a vaginal orgasm (as opposed to a clitoral orgasm) was defined as being triggered solely by penile–vaginal intercourse. According to Wilhelm Reich, the lack of womens capacity to have a vaginal orgasm is due to a lack of orgastic potency, which he believed to be the result of cultures suppression of genital sexuality.