Concealed ovulation

Human females have concealed ovulation or hidden estrus. Most female animals show distinctive signs when they are "in heat". These include swelling and redness of the genitalia in baboons and bonobos, pheromone release in the feline family, etc. By comparison, human females have few external signs of fertility. It is difficult to tell, by means of external signs only, whether or not a woman is ovulating at the time. Humans are the only mammal to lack obvious, visible manifestations of ovulation, although some argue that the extended estrus period of the bonobo (reproductive-age females are in heat for 75% of their menstrual cycle)^[1] has a similar effect to the lack of a "heat" in human females.^[2]

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While women can be taught to recognize their own ovulation (fertility awareness), whether men can detect ovulation in women is highly debated. At least one recent study has argued that men are more likely to initiate sex with fertile women^[3], while another has found male-initiated sex to occur at a constant rate throughout the menstrual cycle.^[4]

One group of authors has theorized that concealed ovulation and menstruation were key factors in the development of symbolic culture in early human society.^[5]

See also

• Menstrual cycle
• Mittelschmerz
• Ovulation

References

1. ^ Lanting, Frans; Waal, F. B. M. de (1997). Bonobo: the forgotten ape. Berkeley: University of California Press, p.107. ISBN 0-520-20535-9. Retrieved on 2007-09-05. 
2. ^ Stanford, Craig B. (March-April 2000). "The Brutal Ape vs. the Sexy Ape? The Make-Love-Not-War Ape". American Scientist 88 (2): 110. doi:10.1511/2000.2.110. Retrieved on 2007-09-05.
3. ^ Petrie, M. (August 2004). "Female facial attractiveness increases during the fertile phase of the menstrual cycle". Proc.R.Soc.Lond.B (Suppl.) 271: S270-S272. doi:10.1098/rsbl.2004.0174.
4. ^ Susan B. Bullivant, Sarah A. Sellergren, Kathleen Stern, et al (February 2004). "Women's sexual experience during the menstrual cycle: identification of the sexual phase by noninvasive measurement of luteinizing hormone". Journal of Sex Research 41 (1): 82-93. PMID 15216427.
5. ^ Chris Knight (1991). Blood relations: menstruation and the origins of culture. New Haven, Conn: Yale University Press. ISBN 0-300-04911-0. 
   Knight, Chris; Camilla Power & Ian Watts (1995). "The Human Symbolic Revolution: A Darwinian Account". Cambridge Archaeological Journal 5 (1): 75-114. Retrieved on 2006-12-13.

Further reading

• Marlowe, F.W. (October 2004). "Is human ovulation concealed? Evidence from conception beliefs in a hunter-gatherer society: the Hadza of Tanzania". Archives of Sexual Behavior 33 (5): pp. 427-432. Retrieved on 2007-10-11.
• Pawłowski, Bogusław (June 1999). "Loss of Oestrus and Concealed Ovulation in Human Evolution". Current Anthropology 40 (3): pp. 257-276. Retrieved on 2007-10-11.