Journal of Evolutionary Psychology
Volume/Issue:
Volume 9: Issue 4
A preliminary investigation of synchronous pregnancies in women
Authors:
K. WorthUniversity of Ottawa, Ottawa, Canada

Search for other papers by K. Worth in
Current site
Google Scholar
PubMedClose
and
Maryanne L. FisherSaint Mary's University, Halifax, Canada
Department of Psychology, Saint Mary's University, 923 Robie Street, Halifax, Nova Scotia, B3H 3C3, Canada

Search for other papers by Maryanne L. Fisher in
Current site
Google Scholar
PubMedClose
Pages:
309–326
Online Publication Date:
01 Dec 2011
Publication Date:
01 Dec 2011
Article Category:
Research Article
DOI:
https://doi.org/10.1556/jep.9.2011.4.3
Keywords:
pregnancy; sharing behavior; mothering; women's sexuality; menstrual synchrony
Restricted access

Abstract

Menstrual synchrony is when the menstrual cycles of friends or family members coincide, such that women conform to the same cycle. In this paper, we propose for the existence of synchronous pregnancies, which may be analogous to menstrual synchrony. Menstrual synchrony is a well studied topic, whereas synchronous pregnancies among friends or family members is an overlooked area of investigation. In this exploratory study of 81 pregnant women, we hypothesize that women's pregnancies are synchronized with those of friends or family members. We also examine whether women intentionally plan their pregnancies in accordance with these individuals. Finally, we investigate the sharing of resources among women who have simultaneous pregnancies. Our findings suggest that the pregnancies of women are more synchronized with friends than family members, and often the synchronicity is unplanned. The majority of women indicated that they intend to share resources (including parenting) with others who are pregnant at the same time, or who have recently given birth. Using an evolutionary framework, we propose that the sharing of resources is highly valuable and might represent a reason for women to, albeit inadvertently, have synchronized pregnancies.

  • R. D. Alexander 1975 Natural selection and specialized chorusing behavior in acoustical insects D. Pimental Insects, Science and Society Academic Press New York 37 77.

    • Search Google Scholar
    • Export Citation

  • R. Axelrod W. D. Hamilton 1981 The evolution of cooperation Science 211 1390 1396.

  • P. A. Bell L. M. Kline W. A. Barnard 1998 Friendship and freedom of movement as moderators of sex differences in interpersonal distancing Journal of Social Psychology 128 305 310.

    • Search Google Scholar
    • Export Citation

  • B. C. R. Bertram 1975 Social factors influencing reproduction in wild lions Journal of Zoology 177 463 482.

  • N. Burley 1979 The evolution of concealed ovulation American Naturalist 114 835 858.

  • N. A. Chagnon 1979 Mate competition, favoring close kin, and village fissioning among the Yanomamo Indians N. A. Chagnon W. Irons Evolutionary Biology and Human Social Behavior Duxbury Press North Scituate 213 237.

    • Search Google Scholar
    • Export Citation

  • M. Daly M. Wilson 1988 Evolutionary social psychology and family homicide Science 242 519 524.

  • Elliott, D. W. (2001): Peer pressure. In: Lerner, J. V., Lerner, R. M., Finkelstein, J. (eds): Adolescents in America: A-M, pp. 494–497.

    • Search Google Scholar
    • Export Citation

  • S. T. Emlen N. J. Demong 1975 Adaptive significant of synchronized breeding in a colonial bird: A new hypothesis Science 188 1029 1031.

    • Search Google Scholar
    • Export Citation

  • L. A. Fairbanks 1990 Reciprocal benefits of allomothering for female vervet monkeys Animal Behavior 40 553 562.

  • J. A. French J. A. Stribley 1985 Synchronization of ovarian cycles within and between social groups in golden lion tamarins (Leontopithecus rosalia) American Journal of Primatology 12 469 478.

    • Search Google Scholar
    • Export Citation

  • R. E. Frisch 1984 Body fat, puberty and fertility Biological Reviews 59 161 188.

  • R. Gattermann K. Ulbrich R. Weinandy 2002 Asynchrony in the estrous cycles of golden hamsters (Mesocricetus auratus) Hormones and Behavior 42 70 77.

    • Search Google Scholar
    • Export Citation

  • C. A. Graham 1991 Menstrual synchrony: An update and review Human Nature 2 293 311.

  • Gulli, C. (2008, January 17): Suddenly teen pregnancy is cool? MacLeans, retrieved online from http://www.macleans.ca/culture/lifestyle/article.jsp?content=20080_117_99497_99497, December, 11, 2008.

  • M. Gurven W. Allen-arave K. Hill A. M. Hurtado 2001 Reservation food sharing among the Ache of Paraguay Human Nature 12 273 297.

  • W. D. Hamilton 1964 The genetical evolution of social behaviour Journal of Theoretical Biology 7 1 52.

  • G. Handelmann R. Ravizza W. J. Ray 1980 Social dominance determines estrous entrainment among female hamsters Hormones and Behavior 14 107 115.

    • Search Google Scholar
    • Export Citation

  • M. Haselton K. Gildersleeve 2011 Can men detect ovulation? Current Directions in Psychological Science 20 87 92.

  • S. Hrdy 2009 Mothers and Others: The Evolutionary Origins of Mutual Understanding Harvard University Press Cambridge, MA.

  • L. R. Jarett 1984 Psychosocial and biological influences on menstruation: Synchrony, cycle length and regularity Psychoneuroendocrinology 9 21 28.

    • Search Google Scholar
    • Export Citation

  • Jayson, S. (2009, July 1): Teen birth rates up in 26 states, USA Today, retrieved August 26, 2009 from http://www.usatoday.com/news/health/2009-01-07-teenbirths_N.htm.

    • Search Google Scholar
    • Export Citation

  • R. A. Kiltie 1982 On the significance of menstrual synchrony in closely associated women American Naturalist 119 414 419.

  • Kingsbury, K. (2008a, June 18): Pregnancy boom at Gloucester High, Time, retrieved online from http://www.time.com/time/world/article/0,8599,1815845,00.html, December 11, 2008.

    • Search Google Scholar
    • Export Citation

  • Kingsbury, K. (2008b, June 23): Gloucester pregnancy plot thickens, Time, retrieved online from http://www.time.com/time/nation/article/0,8599,1817272,00.html, December 11, 2008.

    • Search Google Scholar
    • Export Citation

  • Kingsbury, K. (2008c, June 26): Gloucester principal stands by story, Time, retrieved online from http://www.time.com/time/nation/article/0,8599,1818337,00.html, December 11, 2008.

    • Search Google Scholar
    • Export Citation

  • B. B. Little D. S. Guzick R. M. Malina M. D. Rocha Ferreira 1989 Environmental influences cause menstrual synchrony, not pheromones American Journal of Human Biology 1 53 57.

    • Search Google Scholar
    • Export Citation

  • B. S. Low 1979 Sexual selection and human ornamentation N. A. Chagnon W. Irons Evolutionary Biology and Human Social Behavior Duxbury Press Belmont, CA 462 486.

    • Search Google Scholar
    • Export Citation

  • J. Maynard Smith 1977 Parental investment: a prospective analysis Animal Behavior 25 1 9.

  • M. K. Mcclintock 1971 Menstrual synchrony and suppression Nature 229 5282 244 245.

  • M. K. Mcclintock 1978 Estrous synchrony and its mediations by airborne chemical communication (Ratus norvegicus) Hormones and Behavior 10 264 276.

    • Search Google Scholar
    • Export Citation

  • M. K. Mcclintock 2000 Human pheromones: primers, releasers, or modulators? K. Wallen J. E. Schneider Reproduction in Context: Social and Environmental Influences on Reproduction MIT Press Cambridge, Massachusetts 355 420.

    • Search Google Scholar
    • Export Citation

  • L. E. L. Rasmussen B. A. Schulte 1998 Chemical signals in the reproduction of Asian (Elephas maximus) and African (Loxodonta africana) elephants Animal Reproduction Science 53 19 34.

    • Search Google Scholar
    • Export Citation

  • M. L. Reaka 1976 Lunar and tidal periodicity molting and reproduction in Stomatopod Crustacea: A selfish herd hypothesis Biology Bulletin 150 468 490.

    • Search Google Scholar
    • Export Citation

  • J. C. Schank 2000 Menstrual-cycle variability and measurement: Further cause for doubt Psychoneuroendocrinology 25 837 847.

  • J. C. Schank 2001 Do Norway rats (Rattus norvegicus) synchronize their estrous cycles? Physiology and Behavior 72 129 139.

  • J. C. Schank 2001 Oestrous and birth synchrony in Norway rats, Rattus norvegicus Animal Behavior 62 409 415.

  • J. C. Schank 2004 Avoiding synchrony as a strategy of female mate choice Nonlinear Dynamics, Psychology, and Life Sciences 8 147 176.

  • K. Stern M. K. Mcclintock 1998 Regulation of ovulation by human pheromones Nature 392 6672 177 179.

  • B. I. Strassman 1997 The biology of menstruation in Homo sapiens: Total lifetime menses, fecundity, and nonsynchrony in a natural-fertility population Current Anthropology 38 123 129.

    • Search Google Scholar
    • Export Citation

  • B. I. Strassman 1999 Menstrual synchrony: Cause for doubt Human Reproduction 14 579 580.

  • W. R. Trevathan M. H. Burleson W. L. Gregory 1993 No evidence for menstrual synchrony in lesbian couples Psychoneuroendocrinology 18 425 435.

    • Search Google Scholar
    • Export Citation

  • R. L. Trivers 1971 The evolution of reciprocal altruism Quarterly Reviews in Biology 46 35 57.

  • J. Wallis 1985 Synchrony of swelling in captive group-living chimpanzees (Pan troglodytes) International Journal of Primatology 6 335 350.

    • Search Google Scholar
    • Export Citation

  • N. M. Weissenböcka H. M. Schwammerb T. Ruf 2009 Estrous synchrony in a group of African elephants (Loxodonta africana) under human care Animal Reproduction Science 113 322 327.

    • Search Google Scholar
    • Export Citation

  • A. Weller L. Weller 1992 Menstrual synchrony in female couples Psychoneuroendocrinology 17 171 177.

  • L. Weller A. Weller 1993 Multiple influences of menstrual synchrony: Kibbutz roommates, their best friends, and their mothers American Journal of Human Biology 5 173 179.

    • Search Google Scholar
    • Export Citation

  • A. Weller L. Weller 1997 Menstrual synchrony under optimal conditions: Bedouin families Journal of Comparative Psychology 111 2 143 151.

    • Search Google Scholar
    • Export Citation

  • K. D. Wells 1977 The social behavior of anuran amphibians Animal Behavior 25 666 693.

  • H. C. Wilson 1992 A critical review of menstrual synchrony research Psychoneuroendocrinology 17 6 565 591.

  • Z. Yang J. C. Schank 2006 Women do not synchronize their menstrual cycles Human Nature 17 4 434 447.

  • A. Ziomkiewicz 2006 Menstrual synchrony: Fact or artifact? Human Nature 17 4 419 432.

  • Collapse
  • Expand
Cover Journal of Evolutionary Psychology
Journal of Evolutionary Psychology
Print ISSN:
1789-2082
Online ISSN:
2060-5587

Journal of Evolutionary Psychology 
Language English
Size  
Year of
Foundation		 2007 (2003)
Publication
Programme		 changed title
Volumes
per Year		  
Issues
per Year		  
Founder Akadémiai Kiadó
Founder's
Address		 H-1117 Budapest, Hungary 1516 Budapest, PO Box 245.
Publisher Akadémiai Kiadó
Publisher's
Address		 H-1117 Budapest, Hungary 1516 Budapest, PO Box 245.
Responsible
Publisher		 Chief Executive Officer, Akadémiai Kiadó
ISSN 1789-2082 (Print)
ISSN 2060-5587 (Online)

Monthly Content Usage

Abstract Views Full Text Views PDF Downloads
Aug 2022 0 0 0
Sep 2022 0 0 0
Oct 2022 1 0 0
Nov 2022 2 0 0
Dec 2022 5 0 0
Jan 2023 12 0 1
Feb 2023 0 0 0