Re: Sexual Jealousy

From: Stevan Harnad (
Date: Sun Dec 03 1995 - 20:42:06 GMT

> From: "Lee liz" <>
> Date: Wed, 29 Nov 1995 09:09:31 GMT
> Is it just simply that animals displaying
> [jealousy] have passed on this characteristic which has become
> more concentrated with the passage of time? In making sure your
> partner only has you as a mate, the only genes passed on will be
> yours as a couple, therefore this trait will continue - please tell
> me I'm right Stevan!!
> But what I don't understand is - why did this behaviour win and keep a
> mate in the first place? And why was it valued by the mate - could
> the mate not have just left and found another if jealousy is a turn
> off? So it must have been seen as, at least, a reasonable piece of
> behaviour if not one to be admired? Or is this just another random
> characteristic which is sort of "by the way"?

There are two problems here: First, you always have to remember to
think separately about proximal and distal causes. Sexual jealousy is
somthing you FEEL, and hence it is proximal, and we are trying to
explain WHY you would feel it by finding what distal advantage it might
have given those ancestors who felt it, advantages in terms of survival
and/or reproductive success. (Distal = far, Darwinian. Proximal = near,

Now our ancestors definitely did not feel anything, proximally, about
"passing on their genes." The gene success story is distal. They might
well have felt jealous about their partners, but we're trying to figure
out WHY.

In seminar I gave a clue: Sexual jealousy is not likely to have the same
distal basis in men and women, because for women there is no uncertainty
about whether the baby in which they are investing nine months during
pregnancy and many more in successfully rearing it until the age of
independence is really their own. Not so for men. They could be
investing in someone else's genes, and that unfortunate tendency would
be a sure ticket to genetic oblivion. So male sexual jealousy would be
connected with concerns about paternity (distally: proximally it would
just take the form of sexual and romantic jealousy, and its concerns).

But it takes two to rear young successfully, and the female only gets
a dozen or fewer chances at genetic immortality (that's more than the
number of preganancies that are likely to lead to a surviving adult
child in one human lifetime, especially in the "original environment" in
which these traits evolved). So she needs to be choosy in selecting whom to
risk those precious few pregnancies with: She not only needs someone who
is genetically and physically fit, but also someone who will likewise
invest his resources in the child-rearing. So female jealousy is likely
to be focused on signs of commitment in a potential mate (and fidelity
in an actual one), because females who were indifferent to that would
have become pregnant and been abandoned, and hence less likely to be
able to rear their kids to independence, and hence that indifference
would NOT be passed on.

The male does not just have a dozen potential offspring, but a
limitless number of them -- IF he adopts a reproductive strategy of
mating with as many females and possible but not sticking around to be
tied down. Under those conditions, he doesn't even have to bother being
jealous, because he'd have so many chances at the Darwinian lottery, he
could take a "win some, lose some" attitude.

And this is probably how human sexuality would be, if the situation were
symmetric. But whereas the male does not have much to lose from
MANY relatively unselective matings with MANY partners, the female
does. So females don't usually collaborate with males in such strategies.
The male therefore has another strategy, and that is to bond with a
single mate, but to make sure he is the only one (otherwise he has even
fewer genetic lottery tickets than the female!).

What should be apparent from this is not only that sexual jealousy
serves a different distal function in men and women, but that it is all
based on a basic reproductive CONFLICT OF INTEREST between males and
females (because of the nature of mammalian reproduction). What's best
for the goose is not best for the gander, and vice versa.

No wonder there is so much trouble in human sexual relationships! We
don't have an optimal system distally, and so it is hardly optimal
proximally (emotionally). It is good enough to get us by, to the next
generation, but it could hardly be described as a STABLE form of
bonding, of the kind you get in certain birds...

This archive was generated by hypermail 2b30 : Tue Feb 13 2001 - 16:24:14 GMT