<unk>  is the characteristic odor of elderly humans. Much like many animal species, human odor undergoes distinct stages based on chemical changes initiated through the aging process. Research suggests that this enables humans to determine the suitability of potential partners based on age, in addition to other factors. One study suggested that<unk>  may be the result of 2-nonenal, an unsaturated aldehyde which is associated with human body odor alterations during aging; however, there are other hypotheses. Another study failed to detect 2-nonenal at all, but found significantly increased concentrations of benzothiazole, dimethylsulphone, and nonanal on<unk> er subjects. In 2012 the Monell Chemical Senses Center published a press release claiming that the human ability to identify information such as age, illness, and genetic suitability from odor is responsible for the distinctive "old man<unk> ". Sensory neuroscientist Johan Lundström stated, "Elderly people have a discernible underarm odor that younger people consider to be fairly neutral and not very unpleasant."<unk>  is known as in Japan, where much social value is placed on<unk> al grooming, and specific upmarket odor-eliminating soaps are targeted at more elderly consumers.
Old person smell
Body odor
Sense of smell
Mental health of Jesus
Body image 
History of emotions
Sexual function
Body shape