There are normative changes in  sexual interest and arousal across the life span. Fur-
thermore, women in relationships of longer du ration are more likely to report engaging in
sex despite no obvious feelings of sexual desi re at the outset of a sexual encounter com-
pared with women in shorter-duration relationships. Vaginal dryness in older women is
related to age and menopausal status. 
Risk and Prognostic Factors 
Temperamental. Temperamental factors include negati ve cognitions and attitudes about
sexuality and past history of mental disorders. Differences in propensity for sexual excitation
and sexual inhibition may also predict the likelihood of developi ng sexual problems.
Environmental. Environmental factors include relationship difficulties, partner sexual
functioning, and developmental history, such as early relationships with caregivers and
childhood stressors. 
Genetic and physiological. Some medical conditions (e.g., diabetes mellitus, thyroid
dysfunction) can be risk factors for female se xual interest/arousal disorder. There appears
to be a strong influence of genetic factors on vulnerability to sexual problems in women.
Psychophysiological research using vaginal photoplethysmography has not found differ-
ences between women with and without perceived lack of genital arousal.
Culture-Related Diagnostic Issues 
There is marked variability in prevalence rates of low desire across cultures. Lower rates of
sexual desire may be more common among East Asian women compared with Euro-
Canadian women. Although the lower levels of sexual desire and arousal found in men
and women from East Asian countries compared with Euro-American groups may reflect
less interest in sex in those cultures, the possibility remains that such  group differences are
an artifact of the measures used to quanti fy desire. A judgment about whether low sexual