About Sex: The Evolutionary
Importance of Males and Females
There is a
lot of confusion about what it means to be male or female these days.
Masculinity today is maligned and misunderstood. Some believe maleness itself
is inherently destructive and should be eliminated. Others view males as
superfluous. This idea is reflected in the witticism, “A woman needs a man like
a fish needs a bicycle.”
Some view men
as being unsuited for today’s world. In her book, The End of Men and The Rise of Women, Hanna Rosin says, “The feminist
revolution is here. Women are on the rise and men are on the decline. Earlier
this year, women became the majority of the workforce for the first time in
U.S. history. Most managers are now women too. And for every two men who get a
college degree this year, three women will do the same.”
believe that traditional masculinity itself should be eliminated and we’d be
better off just seeing ourselves as human
I have a
different view. Evolutionary science tells us that the division of life into
male and female is very old and males and females have been interacting ever
since. I can’t imagine wolves, lions, gorillas, or chimpanzees having arguments
over what it means to be male or female. One of the glories of being human is
that we have greater choice about our gender roles. Yet, within that diversity
of choice, science tells us that there are important differences between males
book, Gender Gap: The Biology of
Male-Female Differences, evolutionary psychologist David P. Barash and his wife,
Judith Eve Lipton, who is a medical doctor and psychiatrist say, “When it comes
to human nature, the differences between males and females must be acknowledged
as real, important, and downright fascinating. Moreover, when it comes to understanding
those differences, there is no better guide than evolution.”
Legato M.D is Professor Emerita of Clinical Medicine at Columbia University and
is an internationally known academic physician, author, lecturer, and founder
of The Foundation for Gender-Specific Medicine. In her book, Eve’s Rib: The New Science of Gender-Specific Medicine and How
It Can Save Your Life she says, “Everywhere we look, the two sexes are startlingly
and unexpectedly different not only in their internal function but in the way
they experience illness.”
Page, M.D., is professor of biology at the Massachusetts Institute of
Technology (MIT) and director of the Whitehead Institute, where he has a
laboratory devoted to the study of the Y-chromosome. He says, “There are 10 trillion
cells in the human body and every one of them is sex specific.”
It has been
said that our genomes are 99.9% identical from one person to the next. “It
turns out that this assertion is correct,” says Dr. Page, “as long as the two
individuals being compared are both men. It’s also correct if the two
individuals being compared are both women. However, if you compare the genome
of a man with the genome of a woman, you’ll find that they are only 98.5%
identical. In other words, the genetic difference between a man and a woman are
15 times greater [the difference between .1 and 1.5] than the genetic
difference between two men or between two women.”
Men can’t be
fully alive to themselves, to the women they love, to their families and
friends, unless they understand and embrace their maleness.
men are needed more than ever. It is time for men to come together at this time
of peril to help bring about “the more beautiful world our hearts know is
possible,” as my colleague Charles Eisenstein
poetically describes it. In order to do so, we have to understand the following
findings from the evolutionary science.
The 16 Elements of My Good Men Manifesto
Recognize that our male lineage
of males and females is not a recent phenomenon. Evolutionary science tells us
that the division of life into male and female began one billion years ago. Drs. Barash and Lipton say, “The
world is divided into males and females. Nearly all animals, as well as most
plants, have two recognizable sexes: male and female. Every once in a while,
one encounters a person whose gender is difficult to determine by casual
examination. Most of the time, however, there is little doubt about an
individual’s sexual identity.
Understand the key elements of
sexual psychology and evolution.
Evolutionary Psychologist David M. Buss, author of the textbook Evolutionary Psychology: The New Science of the Mind, “Human sexual psychology evolved over
millions of years to cope with ancestral adaptive problems, before the advent
of modern contraceptive technology. Humans still possess this underlying sexual
psychology, even though the current environment has changed.”
biologist, Robert Trivers, offers two profound predictions that help us
understand male and female sexual psychology:
The sex that
invests more in offspring, typically, but not always, the female, will be more
discriminating or selective about mating.
The sex that
invests less in offspring will be more competitive for sexual access to the
“What competing is to males,” say
Barash and Lipton, “choosing is to females.”
“In the human
case,” says David Buss, “it is clear that women have greater obligatory parental investment. To produce a single child, women must
endure a nine-month pregnancy, whereas men can produce that same child with as
little as a few minutes of investment.”
males and females want to pick the best mate so that their offspring survive
and thrive. “When it comes to long-term mating or marriage,” says Buss, “it is
equally clear that both men and women invest heavily in children, and so the
theory of parental investment predicts that both sexes should be very choosy
Appreciate the biological basis
of males and females.
have a very simple and useful definition of what is male and what is female,
whether we are fish, ferns, or human beings. An individual can either make many
small gametes (sex cells) or fewer but larger gametes. The individuals that
produce smaller gametes are called “males” and the ones that produce larger
gametes are called “females.”
An article in
the journal, Science, asks “Why Two Sexes Are Better Than
One.” The author says, “Step into a singles bar and it’s pretty clear that
having humanity divided up into two sexes can be frustrating–it cuts the
potential mating pool in half. Biologists have long puzzled over why this
should be. After all, with only one sex, everybody can be a potential mate, so
why bother with two?”
has puzzled scientists, but new studies point to the fact that having two sexes
allows for genetic variation that isn’t possible with only one sex, and though
there are a few exceptions in nature, two sexes seem to more efficient than
three or more.
forward to your comments and questions. I hope you’ll read the full Good Men
Manifesto. If you’d like a copy of the whole thing, drop me a note to Jed@MenAlive.com. Put “Good Men Manifesto” in the subject
line. If you’d like more information about the new book, 12 Rules for Good Men, let me know and I’ll send you the latest information.
 Hanna Rosin. “The End of Men.”
The Atlantic Magazine, July/August, 2010. https://www.theatlantic.com/magazine/archive/2010/07/the-end-of-men/308135/
 David P. Barash and Judith Eve
Lipton. Gender Gap: The Biology of
Male-Female Differences. Transaction Publishers, 2004, p. viii.
 Marianne J. Legato, M.D. Eve’s Rib: The New Science of Gender-Specific Medicine and How
it Can Save Your Life. Harmony Books, 2002, p. 15.
 Charles Eisenstein, The More Beautiful World Our Hearts Know is Possible. North Atlantic Books, 2013.
 Brian Swimme and Thomas
Berry. The Universe Story. HarperSanFrancisco, 1992, p. 270.
 David P. Barash and Judith Eve
Lipton. Gender Gap: The Biology of Male-Female
Publishers, 2004, pp. 18-19.
 David M. Buss. Evolutionary Psychology: The New Science of the Mind. Pearson Education, Inc., 2004, p.
 Robert Trivers. “Parental
investment and sexual selection.” In B. Campbell (ED.) Sexual Selection and the Descent of Man. Aldine, 1972, pp. 136-179.
 Barash and Lipton, Ibid. p. 31.
 Buss, Ibid. p. 107.
 Nature Publishing Group. https://www.nature.com/scitable/definition/gamete-gametes-311.
 “Why are two sexes better than
 Pas de Deux. Why are there only
two sexes? https://slate.com/human-interest/2007/09/why-are-there-only-two-sexes.html
This article first appeared on Jed’s blog.