title: Testosterone, the progesterone/estradiol ratio, and female ratings of masculine facial fluctuating asymmetry for a long-term relationship.
abstract: Idiosyncratic variation within the normal range of androgens levels in women account for significant variations in personality and behavior. We studied if testosterone introduces significant biases in women's perception of fluctuating symmetry of male faces suitability for a long-term relationship. Participants were 145 female college students asked to rate in a two-choice forced paradigm the attractiveness, suitability as a long-term partner, and economic success, fatherliness and fidelity of an asymmetric and a symmetric male face. Since our sample consists of random women interested in participating, whether for personal reasons or because they were paid to participate, we controlled for menstrual phase. All participants provided salivary samples to determine testosterone (T), estradiol (E2) and progesterone (P4) levels. When the P4/E2was low and T low-to-normal, the symmetric face was rated as more attractive, and a desirable long-term partner, but these preferences changed to the opposite when P4/E2was high. In high T women, neither face was rated as more attractive, independently from the P4/E2ratio, but the asymmetric face was preferred as a long-term partner when conception risk was high, changing to prefer the symmetric face as the P4/E2increased. The overall perception of male faces was that the symmetric face was more economical successful but a poor parent and highly unfaithful compared to the asymmetric face. A significant interaction between T and P4/E2for ratings success of the asymmetric face suggests that high levels of feminine T might be related to inter-sexual competition when conception risk is high.
authors.affiliation: Departamento de Etología, Dirección de Neurociencias, Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz, Ciudad de México, Mexico.
authors.forename: Leonor
authors.initials: L
authors.lastname: Hernández-López
authors.affiliation: Departamento de Etología, Dirección de Neurociencias, Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz, Ciudad de México, Mexico.
authors.forename: Dafne M
authors.initials: DM
authors.lastname: García-Granados
authors.affiliation: Departamento de Biología de la Reproducción, Instituto Nacional de Ciencias Médicas y la Nutrición Salvador Zubirán, Mexico.
authors.forename: Roberto
authors.initials: R
authors.lastname: Chavira-Ramírez
authors.affiliation: Departamento de Etología, Dirección de Neurociencias, Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz, Ciudad de México, Mexico. Electronic address: rmc@imp.edu.mx.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Mondragón-Ceballos
mesh_terms: D000293:Adolescent; D000328:Adult; D002755:Choice Behavior / Q000502:physiology; D004958:Estradiol / Q000378:metabolism*; D005145:Face; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D011374:Progesterone / Q000378:metabolism*; D012463:Saliva / Q000378:metabolism; D012727:Sex Characteristics; D012725:Sexual Behavior; D013739:Testosterone / Q000378:metabolism*; D055815:Young Adult
chemical_list: D013739:Testosterone; D011374:Progesterone; D004958:Estradiol
keywords: Facial symmetry; Female mate choice; Ovulatory shift; Progesterone/estradiol ratio; Testosterone