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 stimulation smell in sexual arousal due to its link to immunological profile and offspring viability. This is because olfactory cues may be able to trigger an incest avoidance mechanism by reflecting parts of an individual's genetic equipment. In one study, males rated visual and olfactory information as being equally important for selecting a lover, while females considered olfactory information to be the single most important variable in mate choice. Additionally, when considering sexual activity, females singled out body odour from all other sensory experiences as most able to negatively affect desire. Auditory stimulants may also serve to intensify sexual arousal and