Female sexual arousal can be elicited in laboratory setting by exposure to different kind of sexual stimuli (pictures, videostimuli, imaginery) and measured by vaginal photopletysmography (VPA). Sexual video stimuli have a great potential to elicit female sexual arousal regardless of content, e.g. heterosexual and homosexual intercourse, bonobos engaging in sexual activity (Chivers et al., 2005) or rape (Suschinsky & Lalumière, 2011).
However, videostimuli are too complex to detect the aspects of the stimuli responsible for the elicitation of genital arousal. Some theorists assume, that female genital response is an automatic reaction to any sexual stimuli, preparing a women for a potential sexual intercourse (Laan, 1994).
This was supported by Spape's et al. (2014) findings that female sexual arousal was greater while exposed to a stimuli depicting detail of male erect penises compared to flaccid penises. It is also assumed, that female is more sexually aroused when exposed to attractive men (Chivers et al., 2010).
These assumptions were, however, not directly experimentally tested yet.