Subliminally perceived odours modulate female intrasexual competition: an eye movement study

Abstract

Background: Evidence suggests that subliminal odorants influence human perception and behavior. It has been hypothesized that the human sex-steroid derived compound 4,16-androstadien-3-one (androstadienone) functions as a human chemosignal. The most intensively studied steroid compound, androstadienone is known to be biologically relevant since it seems to convey information about male mate quality to women. It is unclear if the effects of androstadienone are menstrual cycle related.

Methodology/principal findings: In the first experiment, heterosexual women were exposed to androstadienone or a control compound and asked to view stimuli such as female faces, male faces and familiar objects while their eye movements were recorded. In the second experiment the same women were asked to rate the level of stimuli attractiveness following exposure to the study or control compound. The results indicated that women at high conception risk spent more time viewing the female than the male faces regardless of the compound administered. Women at a low conception risk exhibited a preference for female faces only following exposure to androstadienone.

Conclusions/significance: We contend that a woman's level of fertility influences her evaluation of potential competitors (e.g., faces of other women) during times critical for reproduction. Subliminally perceived odorants, such as androstadienone, might similarly enhance intrasexual competition strategies in women during fertility phases not critical for conception. These findings offer a substantial contribution to the current debate about the effects that subliminally perceived body odors might have on behavior.

Figure 1. An example of eye movement trajectories.

Eye movement trajectories following exposure to the control compound or androstadienone for (A) men, (B) women in the HCR phase and (C) women in the LCR phase.

Figure 2. A graphical representation of the groups by item category.

Mean viewing time in the three groups of participants with respect to each category. Bars represent the standard error of means.

Figure 3. A graphical representation of the groups by category.

Mean viewing time in the three groups of participants with respect to each category following exposure to the control compound (panel a) and to androstadienone (panel b). Bars represent the standard error of means.

Figure 4. A graphical representation of the ratings of facial attractiveness by the two groups.

Mean ratings of facial attractiveness for the LCR- phase and HCR- phase women following exposure to the control compound or androstadienone. Bars represent the standard error of means.