Editing Testosterone (section)

====Mammalian studies====
Studies conducted in rats have indicated that their degree of sexual arousal is sensitive to reductions in testosterone. When testosterone-deprived rats were given medium levels of testosterone, their sexual behaviours (copulation, partner preference, etc.) resumed, but not when given low amounts of the same hormone. Therefore, these mammals may provide a model for studying clinical populations among humans with sexual arousal deficits such as [[hypoactive sexual desire disorder]].<ref name="pmid20920505">{{cite journal | vauthors = Harding SM, Velotta JP | s2cid = 1577450 | title = Comparing the relative amount of testosterone required to restore sexual arousal, motivation, and performance in male rats | journal = Hormones and Behavior | volume = 59 | issue = 5 | pages = 666–73 | date = May 2011 | pmid = 20920505 | doi = 10.1016/j.yhbeh.2010.09.009 }}</ref>

Every mammalian species examined demonstrated a marked increase in a male's testosterone level upon encountering a {{em|novel}} female. The reflexive testosterone increases in male mice is related to the male's initial level of sexual arousal.<ref name="pmid16828762">{{cite journal | vauthors = James PJ, Nyby JG, Saviolakis GA | s2cid = 36436418 | title = Sexually stimulated testosterone release in male mice (Mus musculus): roles of genotype and sexual arousal | journal = Hormones and Behavior | volume = 50 | issue = 3 | pages = 424–31 | date = Sep 2006 | pmid = 16828762 | doi = 10.1016/j.yhbeh.2006.05.004 }}</ref>

In non-human primates, it may be that testosterone in puberty stimulates sexual arousal, which allows the primate to increasingly seek out sexual experiences with females and thus creates a sexual preference for females.<ref name="pmid11534996">{{cite journal | vauthors = Wallen K | s2cid = 2214664 | title = Sex and context: hormones and primate sexual motivation | journal = Hormones and Behavior | volume = 40 | issue = 2 | pages = 339–57 | date = Sep 2001 | pmid = 11534996 | doi = 10.1006/hbeh.2001.1696 | citeseerx = 10.1.1.22.5968 }}</ref> Some research has also indicated that if testosterone is eliminated in an adult male human or other adult male primate's system, its sexual motivation decreases, but there is no corresponding decrease in ability to engage in sexual activity (mounting, ejaculating, etc.).<ref name="pmid11534996"/>

In accordance with [[sperm competition]] theory, testosterone levels are shown to increase as a response to previously neutral stimuli when conditioned to become sexual in male rats.<ref name="pmid6665072">{{cite journal | vauthors = Hart BL | s2cid = 42155431 | title = Role of testosterone secretion and penile reflexes in sexual behavior and sperm competition in male rats: a theoretical contribution | journal = Physiology & Behavior | volume = 31 | issue = 6 | pages = 823–27 | date = Dec 1983 | pmid = 6665072 | doi = 10.1016/0031-9384(83)90279-2 }}</ref> This reaction engages penile reflexes (such as erection and ejaculation) that aid in sperm competition when more than one male is present in mating encounters, allowing for more production of successful sperm and a higher chance of reproduction.