Anzeichen für Fruchtbarkeit bei Frauen

Der Spiegel hat einen interessanten Bericht zu Anzeichen von Fruchtbarkeit bei Frauen. 

Der Spiegel verweist zunächst auf die Annahme, dass die fruchtbaren Tage beim Menschen deswegen verdeckt vorliegen, also nicht wie bei Schimpansen durch Schwellungen angezeigt werden, damit insoweit zum einen mehr Anreiz für eine dauerhafte Beziehung und nicht nur Interesse an den den fruchtbaren Tagen besteht und zum anderen damit auch der Seitensprung erleichtert wird, da eine Kontrolle bei Kenntnis der fruchtbaren Tage erleichtert wurde.

Diese Betrachtung würde nun eingeschränkt, da anscheinend verschiedene Anzeichen für die fruchtbaren Tage vorhanden sind:

Forscher der Universität Bern haben nun herausgefunden, wie Fruchtbarkeit sich im Gesicht einer Frau ausdrückt. Dass Fotos von fruchtbaren Frauen attraktiver wirken, war bereits bekannt, nicht jedoch, ob zum Beispiel Änderungen in Hautfarbe, Augenfunkeln oder Gesichtsform für die erhöhte Anziehungskraft der Bilder verantwortlich sind.

Die Studie, die gemeint ist, ist die Folgende:

Recent studies have revealed that there may be perceptible cues to ovulation in humans. This study aims at extending these findings by using female faces that were shape transformed towards a late follicular (fertile) and a luteal (non-fertile) prototype. Fertile prototypes were created by averaging 25 photographs taken of females during ovulation (as determined by ovulation tests); non-fertile prototypes were created by averaging 25 photographs of the same women during the luteal phase. Twenty different (new) female faces were then shape transformed towards the luteal prototype and towards the follicular prototype in 50% and 100% steps. The two 50% transforms and the two 100% transforms were paired, resulting in stimulus pairs of two different difficulties. Thirty-six male participants were asked to choose the more attractive (Task 1), the more caring (Task 2), and the more flirtatious face (Task 3). In a final task the participants were asked to choose the woman with which the participant would have better chances to get a date (Task 4). For all tasks we found a significant preference for the follicular face. In trials with a 100% transformation towards the shape of the prototype, the preference for the follicular stimulus was significantly stronger than in trials with a 50% transformation. We conclude that subtle shape differences in faces are sufficient to trigger men’s preference for a woman in her fertile cycle phase.

Quelle: Men’s preference for the ovulating female is triggered by subtle face shape differences

Die diesbezüglichen Anzeichen genau zu ermitteln, ist aus meiner Sicht hoch interessant. Ich vermute, dass einige der Veränderungen bereits durch Schminke umgesetzt werden.

Dabei sind die Unterschiede wohl schwer bewußt zu erkennen:

Obwohl die Veränderungen mit bloßem Auge kaum erkennbar sind (siehe Fotostrecke oben), bewerteten 36 Männer die ins fruchtbare Spektrum veränderte Gesichter mehrheitlich als attraktiver und schätzen die so veränderten Frauen als fürsorglicher, flirtbereiter und als eher zu einer Verabredung bereit ein.

„Eine so allgemeine Präferenz hatten wir gar nicht erwartet, da fürsorglich und flirtbereit ja nicht unbedingt zusammenpassen“, sagt Autorin Cora Bobst. Als nächstes will sie besser verstehen, wie genau sich die Gesichtszüge verändern, denn offensichtlich ist es nicht: „Wir können bisher nicht nachvollziehen, was den Unterschied ausmacht; die Schwankungen sind extrem subtil.“

Es werden noch weitere Studien dazu genannt:

Recent evidence suggests that the concept of ‘concealed ovulation’ in women should be reconsidered, as there appear to be certain behavioural, visual, olfactory, and vocal cues that serve as indirect cues to female fertility. Here we test the hypothesis that men are able to discern fertile from non-fertile women based on their dance and gait movements. Digital videos of dances and gaits of 48 heterosexual women, aged 19–33 years, were recorded twice, once in the late follicular phase, and once in the mid-luteal phase of their menstrual cycle. Short video clips comprising movement silhouettes of dances and gaits were judged on attractiveness by a total of 200 men. Dances and gaits recorded in the late follicular were rated significantly more attractive compared to recordings in the mid-luteal phase. We suggest that (i) menstrual cycle effects on women’s body movements exist, and (ii) men are sensitive to these effects, as they expressed a stronger preference (via attractiveness judgments) for women’s body movements at times of peak fertility. Our data add body movements to the list of features that show systematic changes across the menstrual cycle and support the assertion that men are able to detect cues of female fertility.

Quelle: Women’s body movements are a potential cue to ovulation

Und:

Previous research has demonstrated that women’s physical appearance or sexual interest is different across the menstrual cycle. However, the nonverbal behavior of women toward men according to their menstrual cycle has not been previously explored. In this study, the gait of women walking ahead a male confederate was recorded with the help of a spy-camera. The amount of time that women spent walking was the first dependent variable whereas the extent to which the women were perceived to be sexually attractive by two judges was the second dependent variable. Comparisons were performed according to the women’s ovulation phase measured with an LH salivary test. Near ovulation, it was found that women walked slower and their gait was subjectively rated as sexier. Such behaviors were interpreted as unconscious desires of women near ovulation to reinforce their attractiveness in order to attract more men and to increase their choice of a partner.

Highlights

► Gait and women’ walking were examined according to their menstrual cycle. ► The amount of time that women spent walking ahead a male was measured. ► The sexiness of their gaits recorded with the help of a spy-camera was evaluated by males. ► Ovulation phase was measured with an LH salivary test. ► Near ovulation, women walked slower and their gait was subjectively rated as sexier.

Quelle: Gait and menstrual cycle: Ovulating women use sexier gaits and walk slowly ahead of men

Und zudem die Geoffrey Miller Studie:

To see whether estrus was really “lost” during human evolution (as researchers often claim), we examined ovulatory cycle effects on tip earnings by professional lap dancers working in gentlemen’s clubs. Eighteen dancers recorded their menstrual periods, work shifts, and tip earnings for 60 days on a study web site. A mixed-model analysis of 296 work shifts (representing about 5300 lap dances) showed an interaction between cycle phase and hormonal contraception use. Normally cycling participants earned about US$335 per 5-h shift during estrus, US$260 per shift during the luteal phase, and US$185 per shift during menstruation. By contrast, participants using contraceptive pills showed no estrous earnings peak. These results constitute the first direct economic evidence for the existence and importance of estrus in contemporary human females, in a real-world work setting. These results have clear implications for human evolution, sexuality, and economics.

Quelle: Ovulatory cycle effects on tip earnings by lap dancers: economic evidence for human estrus (PDF)

Es ist nicht anzunehmen, dass sie verdeckte (wenn anscheinend auch nicht so verdeckte) Ovulation ein kultureller Faktor ist. Wir nehmen diese Informationen unterbewusst auf. Solche Zeichen, die eben die fruchtbaren Tage anzeigen, unterliegen auf Seiten des Mannes einer starken Selektion: Wer Frauen in diesem Zustand attraktiver findet, der hat höhere Chancen Nachwuchs zu bekommen. Das macht deutlich, wie stark Schönheit mit Biologie verbunden ist.