Sexual arousal though they are generally considered secondary in role to the other three. Erotic stimuli which can result in sexual arousal can include conversation, reading, films or images, or a smell or setting, any of which can generate erotic thoughts and memories in a person. Given the right context, these may lead to the person desiring physical contact, including kissing, cuddling, and petting of an erogenous zone. This may in turn make the person desire direct sexual stimulation of the breasts, nipples, buttocks and/or genitals, and further sexual activity. Erotic stimuli may originate from a source unrelated to the object of
Sexual arousal of sexual arousal. The degree to which genital and subjective sexual response correspond is termed "concordance". Research has shown a reliable gender difference in concordance of sexual arousal, such that men have a higher level of concordance between genital and subjective sexual responding than women do. Some researchers argue that this gender difference can be attributed to the type of method used to assess genital responding in women. There may be a difference in women's ability to perceive internal versus external genital engorgement subjectively, as measured by vaginal photoplethysmography (VPG) and thermography respectively. Chivers and colleagues found that men's and