> From: "Hewes, Alexa" <ALEXA92@psy.soton.ac.uk>
> Date: Fri, 3 Mar 1995 16:05:49 GMT
>
> I would like to comment on the idea that emerged in the lecture on sex
> differences, of the 'concealed estrus'...
>
> I would like to suggest, that due to the complexity of the human brain
> and our superior intelligence to the animal world, we have developed in
> a way so that we no longer need to rely on instinctual drives to rule
> our behaviour. Perhaps it is the case that the female has evolved in a
> way so that her estrus is now concealed, although this was not always
> the case. There must have been a point in time when it was discovered
> that at a certain time of the month, having sex is very likely to
> result in the female becoming pregnant. Perhaps a certain female didn't
> want to be pregnant so tried to hide the fact that she was ovulating,
> from her potential male partners. As more and more women started using
> this technique as the first historical method of contraception, they
> gradually began to evolve as a species and develop in the way that
> their estrus is naturally concealed as it is today.
"Concealed estrus" is just a figure of speech. Women don't CONSCIOUSLY
conceal estrous (they hardly know when it happens!). It is the CUES to
estrous (like the female baboons red rump) that our species fails to
have.
Your theory also sounds somewhat Lamarckian: In general, acquired traits
cannot be passed on genetically; they are passed on "culturally" (by
imitation or instruction or coercion). I suppose if prehuman females
once had swollen rumps when they ovulated, they could have tried to
conceal them (though our Environment of Evolutionary Adaptedness
probably preceded both the invention of clothing and the knowledge of
the connection between sexuality and reproduction), though it's hard to
see what the advantage of that would have been; in any case, what that
would have led to would have been a culture of concealment. But the
unadvertised human ovulation is not a cultural matter at all. It's
completely involuntary.
So if we drop the conscious strategy and simply ask what advantage
there might have been to a female who HAPPENED to have a less red rump
when she was estrous, it's again hard to see what it might be, because,
as I said, in other mammals, nonestrous females are ignored by males
(and that's no reproductive advantage).
Perhaps it needs to be seen the other way around: That in our species
female noncyclical "sexiness" cues (not clothes or perfume, but the
anatomy our forbears saw) evolved and took on the sexually arousing
role that is usually reserved for advertised estrous. But again it's
not clear why. Some people think there might be a clue in the sexual and
social lives of the Bonobos, who are also sexually active throughout
their cycle (though they do not conceal estrous, and that is still
when sexual activity peaks).
The same Desmond Morris whom Jules mentioned in class in connection
with the possible adaptive value of the female orgasm has a theory that
humans actually evolved sexually arousing "breasts" on their rumps, and
vice-versa, to keep up sexual interest throughout the cycle. (You'll
have to judge for yourselves whether that's just a "Just-So" Story...)
Some Abstacts follow.
Chrs, Stevan
1. Wrangham, Richard W.
The evolution of sexuality in chimpanzees and bonobos.
Human Nature, 1993, v4 (n1):47-79.
ABSTRACT: Discusses the evolution of nonconceptive sexuality in bonobos (pygmy
chimpanzees) and chimpanzees from a functional perspective. Bonobos and
chimpanzees have 3 functions of sexual activity in common (paternity
confusion, practice sex, and exchange for favors), but only bonobos use
sex purely for communication about social relationships. Bonobo
hypersexuality appears closely linked to the evolution of female-female
alliances. It is suggested that these alliances were made possible by
relaxed feeding competition, that they were favored through their effect
on reducing sexual coercion, and that they are ultimately responsible for
the relaxed social conditions that allowed the evolution of communication
sex. A scenario for the evolution of bonobo hypersexuality is offered.
1. Furuichi, Takeshi.
Social interactions and the life history of female Pan paniscus in Wamba,
Zaire.
International Journal of Primatology, 1989 Jun, v10 (n3):173-197.
ABSTRACT: The unit-group of Pan paniscus tends to form one large mixed party
consisting of most of its members. Females stay in the party irrespective
of the estrous state and aggregate in the center. Older females stay in
the most central part. Females leave their natal unit-groups as older
juveniles or in early adolescence and settle in another unit-group after
visiting several. Newly immigrated females become less eager to interact
socially with other females after they have their own offspring. Females
in old age become important members of the unit-group, both as the targets
of association for younger females and as the mothers of high-ranking
males. The consistency of the multimale-multifemale party and the
existence of prominent mother-offspring subunits are unique
characteristics of P. paniscus among the Pongidae.
2. BOOK CHAPTER
Turke, Paul W.
Concealed ovulation, menstrual synchrony, and paternal investment.
IN: Biosocial perspectives on the family. Sage focus editions, Vol. 96.;
Erik E. Filsinger, Ed. Sage Publications, Inc, Newbury Park, CA, US. 1988.
p. 119-136.
ABSTRACT: (from the chapter) analyzing arguments posited to account for
particular changes in the sexual and social characteristics of our early
ancestors... hypothesis for how a somewhat paternal protohominid became a
much more paternal hominid... two reasons why selection acts differently
on males and females... why human males are especially paternal; Alexander
and Noonan hypothesis... evidence (for the evolution of paternal care in
humans); pygmy chimpanzees; hamadryas baboons; marmosets and tamarins...
discuss additional alternatives and/or critiques of the Alexander and
Noonan hypothesis; textbook view of the origin of human paternal care.
3. Turke, Paul W.
Effects of ovulatory concealment and synchrony on protohominid mating
systems and parental roles.
Ethology & Sociobiology, 1984, v5 (n1):33-44.
ABSTRACT: The potential for males to increase fitness by acquiring many mates
is often high and male confidence of paternity is often low; these factors
have been theorized to have precluded the evolution of paternal care in
most species. The present author hypothesizes that ovulatory concealment
and synchrony and extended sexual receptivity constituted pressures that
forced protohominid males to extend consortships and behave increasingly
paternally. Concealment, synchrony, and extended receptivity are expected
to have produced these effects by taxing males' capacities to sexually
monopolize multiple females. Data from the literature on modern humans,
pygmy chimpanzees, hamadryas baboons, and lion tamarins are presented in
support of these arguments.
1. Schroder, Inge.
Concealed ovulation and clandestine copulation: A female contribution to
human evolution.
Ethology & Sociobiology, 1993 Nov, v14 (n6):381-389.
ABSTRACT: Concealed ovulation in human women has generally been interpreted to
have evolved within an a priori multimale social setting. Because there is
evidence that hominids passed through an evolutionary phase with a unimale
social structure, alternative explanations are required. Assuming that
clandestine copulation was a new reproductive strategy of subordinate men,
concealment of ovulation can be regarded as the women's contribution to
the deception of the alpha-male, thus improving the options of female
choice and reducing the risk of infanticide.
2. Baker, Andrew J.; Dietz, James M.; Kleiman, Devra G.
Behavioural evidence for monopolization of paternity in multi-male groups
of golden lion tamarins.
Animal Behaviour, 1993 Dec, v46 (n6):1091-1103.
ABSTRACT: Studied a wild population of golden lion tamarins in which
approximately 40% of groups contained 2 nonnatal adult males. Both males
cared for infants and, in some groups, both males copulated with the
reproductive female. There was evidence for a dominant/subordinate
relationship between males in most groups. Ovulation was probably not
concealed, and dominant males were responsible for almost all sexual
behavior when females were likely to be fertile. A polyandrous group
structure is common in this population, but paternity is probably
monopolized by a single dominant male in most groups.
3. Burt, Austin.
"Concealed ovulation" and sexual signals in primates.
Folia Primatologica, 1992, v58 (n1):1-6.
ABSTRACT: The absence of conspicuous sexual signals in some primates,
particularly humans and vervets, has been interpreted as evidence that
females of these species are "concealing" ovulation from males. This
conclusion is unjustified; the hypothesis that the absence of conspicuous
sexual signals has resulted from the absence of selective pressures
maintaining such adaptations better fits the facts. The related suggestion
that there has been adaptation among females to conceal ovulation from
their own consciousness is also unjustified. Many hypotheses for the
function of sexual signals do not account for their conspicuousness.
Conspicuous sexual signals function to communicate to distant receivers
and/or to convince reluctant receivers.
4. Steklis, Horst D.; Whiteman, Catherine H.
Loss of estrus in human evolution: Too many answers, too few questions.
Ethology & Sociobiology, 1989 Oct, v10 (n6):417-434.
ABSTRACT: Models addressing the importance of loss of estrus in human evolution
assume that endogenous hormonal fluctuations have less influence on human
female sexuality than cognitive and socioenvironmental factors. The role
of hormones and other factors in the reproductive patterns of primates
must be viewed in the context of species' life history and ecological
constraints. Human studies on the relationship between the menstrual cycle
and sexual behavior have been limited to Western women in industrialized
societies and thus may not reveal evolved behavioral-physiological
patterns. No single pattern emerges that can be said to characterize the
human female, and no conclusion can be reached regarding the relationship
between cyclic hormonal fluctuations and sexual behavior and, thus,
whether human ovulation is concealed.
5. Small, Meredith F.
Female primate sexual behavior and conception: Are there really sperm to
spare?
Current Anthropology, 1988 Feb, v29 (n1):81-100.
ABSTRACT: Argues that female primates may mate with multiple partners or with
one partner repeatedly (even at times when conception is unlikely) to
maximize the likelihood of conception, particularly in circumstances where
male sperm is in scarce supply. It is noted that nonconceptive mating
brings costs, such as exposure to male aggression and detraction from
foraging and caring for young. Implications for the evolution of human
female sexual behavior and concealed ovulation are discussed. The study is
followed by 7 commentaries and a response to those commentaries by the
present author.
6. BOOK CHAPTER
van der Dennen, Johan M. G.
The sociobiology of behavioural sex differences: III. Aspects of sex and
aggression in man.
IN: The nature of the sexes: The sociobiology of sex differences and the
"battle of the sexes.". Essays in human sociology, Vol. 3.; J. M. G. van der
Dennen, Ed. Origin Press, Groningen, Netherlands. 1992. p. 195-219.
Pub type: Review; Literature Review.
ABSTRACT: (summarized) Discusses male dominance by examining the aspects of sex
and aggression.
(from the chapter) pseudosex; sexual jealousy; rape and courtship
violence; group rape ('gangbang"; is human rape really adaptive; machismo;
romantic love; sexual selection in the evolution of man; concealment of
ovulation, and polygyny in human evolution.
7. BOOK, EDITED
Filsinger, Erik E., ed.
Biosocial perspectives on the family. Sage Publications, Inc; Newbury
Park, CA, US, 1988.
Series title: Sage focus editions, Vol. 96.
ABSTRACT: (from the preface) The resurgence of interest in biological
explanations of human behavior has stimulated family scholars to challenge
the cultural and environmental explanations most of us have learned in
graduate school. Because families constitute the social mechanism for
genetic transmission, the interest should not be surprising. While
cultural determinism may not be dead, it appears to me that the most
exciting breakthroughs are the biosocial.... The contributors to this
volume are noted experts in their fields: family science, sociology,
psychology, anthropology, and child development. The selection of chapters
represents a continuum from the more proximate mechanisms of biological
input to the more distal, evolutionary explanations. The last three
chapters constitute contributions from authors who were asked to use the
previous chapters as a starting point for their own thoughts and critique.
To the nonbeliever, those chapters may provide balance to what is
otherwise an admittedly one-sided presentation of a position.
Contents:
Preface.
Biology reexamined: The quest for answers. Erik E. Filsinger. (Chapter
record available).
The family and the biological base of human sociality. Pierre L. van den
Berghe. (Chapter record available).
Biological influences upon the development of sexual orientation. Brian
Anthony Gladue. (Chapter record available).
Odor communication and parent-child interaction. Richard A. Fabes and Erik
E. Filsinger. (Chapter record available).
Concealed ovulation, menstrual synchrony, and paternal investment. Paul W.
Turke. (Chapter record available).
Sociobiology and the study of family conflict. Jetse Sprey. (Chapter
record available).
The feasibility of an integration. Gary R. Lee. (Chapter record
available).
Sociobiology and the family: A focus on the interplay between social
science and biology. Becky Heath Ladewig, Stephen J. Thoma and John H.
Scanzoni. (Chapter record available).
Sociobiology and the family: Promise versus product. Kay Michael Troost.
(Chapter record available).
About the contributors.
8. BOOK CHAPTER
Turke, Paul W.
Concealed ovulation, menstrual synchrony, and paternal investment.
IN: Biosocial perspectives on the family. Sage focus editions, Vol. 96.;
Erik E. Filsinger, Ed. Sage Publications, Inc, Newbury Park, CA, US. 1988.
p. 119-136.
ABSTRACT: (from the chapter) analyzing arguments posited to account for
particular changes in the sexual and social characteristics of our early
ancestors... hypothesis for how a somewhat paternal protohominid became a
much more paternal hominid... two reasons why selection acts differently
on males and females... why human males are especially paternal; Alexander
and Noonan hypothesis... evidence (for the evolution of paternal care in
humans); pygmy chimpanzees; hamadryas baboons; marmosets and tamarins...
discuss additional alternatives and/or critiques of the Alexander and
Noonan hypothesis; textbook view of the origin of human paternal care.
9. Turke, Paul W.
Effects of ovulatory concealment and synchrony on protohominid mating
systems and parental roles.
Ethology & Sociobiology, 1984, v5 (n1):33-44.
ABSTRACT: The potential for males to increase fitness by acquiring many mates
is often high and male confidence of paternity is often low; these factors
have been theorized to have precluded the evolution of paternal care in
most species. The present author hypothesizes that ovulatory concealment
and synchrony and extended sexual receptivity constituted pressures that
forced protohominid males to extend consortships and behave increasingly
paternally. Concealment, synchrony, and extended receptivity are expected
to have produced these effects by taxing males' capacities to sexually
monopolize multiple females. Data from the literature on modern humans,
pygmy chimpanzees, hamadryas baboons, and lion tamarins are presented in
support of these arguments.
10. Gray, J. Patrick; Wolfe, Linda D.
Human female sexual cycles and the concealment of ovulation problem.
Journal of Social & Biological Structures, 1983 Oct, v6 (n4):345-352.
ABSTRACT: Contends that sociobiologists have generally rejected the social
bonding explanations of human sexual behavior that were widely accepted a
few years ago without presenting a generally accepted alternative
explanation. Seven recent hypotheses advanced to account for an aspect of
human female sexual behavior, the concealment of ovulation, are reviewed.
Implications of research on the distribution of human female activity
throughout the menstrual cycle for these 7 hypotheses are discussed.
11. Daniels, Denise.
The evolution of concealed ovulation and self-deception.
Ethology & Sociobiology, 1983, v4 (n2):69-87.
ABSTRACT: Discusses the phenomenon of concealed ovulation in humans, which is
strikingly unusual among primates and most mammals. Concealed ovulation
can be best understood in the perspective of evolutionary theory. It would
seem that stimulus signs are essential to reproductive success because
activities would be drawn to maximizing the probability of copulation when
the female is fertile. Human reproductive success and survival, however,
depends not only on lack of physical cues of ovulation, but also on lack
of psychological awareness. Through exploring the meaning of this apparent
incongruity, concealed ovulation is shown to be adaptive. It is
hypothesized that females who concealed ovulation were favored because the
group in which they lived maintained a peaceful stability that facilitated
monogamy, sharing, and cooperation. Several other theories of concealed
ovulation are reviewed and compared.
12. Barash, David P.
The fitness of categories and vice versa.
Neuroscience & Biobehavioral Reviews, 1982 Spring, v6 (n1):95-104.
Pub type: Literature Review; Review.
ABSTRACT: Presents 2 propositions useful in a evolutionary analysis of the
origins of complex biobehavioral categories: (1) Such categories derive
from the gradual accumulation of a very large number of categoric
alternatives, each of which is very small. (2) Fitness considerations
provide valuable insight into the ultimate decision process whereby these
microcategories, and eventually, all more complex categories, are
achieved. These propositions are illustrated with examples of complex
biobehavioral categories, such as reproductive strategies, mate selection,
and foraging behaviors. The application of sociobiology to human behavior
and sociobiology's usefulness for explaining such human phenomena as the
female breast, nepotism, consciousness, and concealed ovulation are
examined.
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