Sex differences in olfactory self-recognition Steven M. Platek, Rebecca L. Burch, Gordon G. Gallup, Jr.* Department of Psychology, State University of New York at Albany, 1400 Washington Avenue, Albany, NY 12222, USA Received 9 June 2000; received in revised form 13 April 2001; accepted 16 April 2001 Abstract This study investigated sex differences in the ability to recognize one’s own body odor accompanied by an attempt to account for variance in this ability by comparing ratings of self-body odor and other odors on a visual analog scale (VAS). Whereas over half (59.4%) of the females were able to identify their own odor, only one out of 18 (5.6%) males were able to recognize their own odor. Females rated their own secretions as significantly lower on a pleasant-positive factor than males rated their own odors (axillary secretions), but there was no difference in ratings between those who could and those who could not identify their own odor. The dimensions tapped by the VAS used in this study do not seem to account for the ability to identify one’s own body odors. D 2001 Elsevier Science Inc. All rights reserved. Keywords: Pheromones; Chemical communication; Olfactory self-recognition; Body odor 1. Introduction Karlson and Luscher [1] first described pheromones as airborne chemical signals excreted by one member of a species and received by another member of that species, triggering specific reactions that affect behavior, fertility, and/or development. Today, it is well known that animals can and do use chemical, pheromonal means for communicating important information between members of the same species [2,3]. Humans also exude chemicals that can result in physiological [4,5], menstrual timing [6 – 8], and behavioral changes [9]. These types of pheromones are traditionally referred to as releaser, primer, and signaling pheromones. Recently, McClintock [10] has suggested the existence of state-modulating pheromones. She theorizes that this type of pheromone acts to modulate an individual’s state/mood, and that modulation of the state is situation- or context-depend- ent. These types of chemosignals are a part of a pheromonal mechanism that guides ongoing behavior appropriate for a given context [9]. She hypothesizes that state-modulating pheromones affect (1) the regulation of all sensory inputs during exposure and (2) the state or mood of the individual, therefore, affecting the way the individuals react to incom- ing stimuli. For example, Chen and Haviland-Jones [11] have demonstrated a decrease in nonclinical depression scores in individuals exposed to the underarm secretions of older women as opposed to those of young adult men and women, prepubertal men and women, and older men. Putative human pheromones, as well as other chemical structures that may play a part in chemical communication, have been isolated from the axillary region of humans [12– 17] and used to demonstrate releaser and signaling pher- omonal effects [7,8]. It was not until recently that the state- modulating effects of pheromones were examined in humans. Jacob and McClintock [18] were the first to show clearly that the isolated steroid and putative human pher- omone 4,16-androstadien-3-one (androstadienone) may have state-modulating effects. Monti-Bloch et al. [19] have suggested that androstadienone and 1,3,5(10)16-estrate- trean-3-ol exhibit sex-specific effects on mood regulation as measured by membrane potentials of the human vomer- onasal organ. The context in which an individual perceives or receives information via volatile chemicals has been shown to be important for the way that individual actually perceives a specific volatile [19]. Thus, one would expect to see predictable patterns in the ability to respond to one’s own volatile secretions to the extent that they may interact with environmental volatiles causing actual changes in sensory perception or changes in the attributions given to any environmental volatile. Since one’s most proximate environ- 0031-9384/01/$ – see front matter D 2001 Elsevier Science Inc. All rights reserved. PII:S0031-9384(01)00539-X * Corresponding author. Tel.: +1-518-442-4852; fax: +1-518-442- 4867. E-mail address: gallup@csc.albany.edu (G.G. Gallup). Physiology & Behavior 73 (2001) 635 – 640