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Can men and women be just friends?

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We tested evolution-based hypotheses about (1) sex differences in perceived benefits and costs of opposite-sex friendship and (2) differences in perceived benefits of same-sex friendships and opposite-sex friendships. In the Preliminary Study (N= 400), an act nomination procedure was used to identify the benefits and costs of same-sex friendships and opposite-sex friendships. In Study 1, a total of 231 participants (100 men, 131 women) evaluated the frequency of occurrence of 100 benefits and costs in their closest same-sex friendship or opposite-sex friendship. In Study 2, a total of 229 participants (92 men, 137 women) evaluated how beneficial and how costly each would be if it were to occur in their closest same-sex friendship or opposite-sex friendship. Results supported several key hypotheses. Men perceived sex with their opposite-sex friends as more beneficial than did women. Women reported receiving protection from their opposite-sex friends more often than did men, and they perceived the protection as highly beneficial. Both men and women reported receiving information from opposite-sex friends about how to attract mates, and they perceived this information as beneficial. The discussion focuses on whether these benefits reflect an evolved psychology of opposite-sex friendship, or instead are incidental by-products.
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Can men and women
be
just
friends?
APRIL
L.
BLESKE
AND
DAVID
M.
BUSS
University
of
Texas
at
Austin
Abstract
We
tested evolution-based hypotheses about (1) sex differences in perceived benefits and costs of
opposite-sex friendship and
(2)
differences in perceived benefits
of
same-sex friendships and opposite-sex
friendships.
In
the Preliminary Study
(N
=
400), an act nomination procedure was used to identify the
benefits and costs of same-sex friendships and opposite-sex friendships.
In
Study
1,
a total of 231 participants
(100 men, 131 women) evaluated the frequency of occurrence
of
100 benefits and costs in their closest
same-sex friendship or opposite-sex friendship. In Study 2, a total
of
229 participants
(92
men, 137 women)
evaluated how beneficial and how costly each would be
if
it were to occur in their closest same-sex friendship
or opposite-sex friendship. Results supported several key hypotheses. Men perceived sex with their
opposite-sex friends as more beneficial than did women. Women reported receiving protection from their
opposite-sex friends more often than did men, and they perceived the protection as highly beneficial. Both
men and women reported receiving information from opposite-sex friends about how to attract mates, and
they perceived this information as beneficial. The discussion focuses
on
whether these benefits reflect an
evolved psychology
of
opposite-sex friendship, or instead are incidental by-products.
Much of human social interaction occurs
within the context of enduring relationships,
such as kinships, mateships, and friendships.
From an evolutionary perspective, kinships
and mateships are important because of
their direct links with inclusive fitness
(Hamilton, 1964): kin carry copies
of
our
genes, and mates are our reproductive part-
ners. Friendships, however, are more puz-
zling from an evolutionary perspective.
Friends do not share copies of our genes,nor
do we generally reproduce with our friends.
Around the world, however, people form
friendships that last for days, years, and even
a lifetime. This requires explanation.
The authors thank Barry Friedman, Martie Haselton,
and Todd Shackelford for their helpful comments
on
earlier versions of this article.
Portions
of
this article were presented at the an-
nual convention of the Human Behavior and Evolu-
tion Society, Tucson, Arizona, June 1997.
Address correspondence to April
L.
Bleske,
De-
partment
of
Psychology, University
of
Texas, Austin,
TX
78712. E-mail: bleske@mail.utexas.edu.
In principle, friendships can provide a
bounty
of
benefits that historically may
have been linked directly or indirectly with
reproduction. Friends may offer us food
and shelter or take care of us when we are
ill, thus helping to solve adaptive problems
of
survival. Friends may introduce us to
potential mates, helping to solve an adap-
tive problem of reproduction. Friends may
also inflict costs on us by betraying our
confidences to enemies, competing for ac-
cess to the same resources, and even com-
peting for the same mates. As illustrated
by Brutus and Caesar, friends can cost us
our lives.
One
of
the complexities
of
friendship is
that some characteristics
of
friendship are
perceived as both beneficial and costly. The
friendship literature, for example, is incon-
sistent on the role
of
sexuality in opposite-
sex friendship. More than half
of
men and
some women report sexual attraction to
their friends (Kaplan
&
Keys, 1997), and
both sexes experience ambiguity about the
sexual boundaries in their opposite-sex
friendships (Swain 1992). Monsour, Beard,
131
132
A.
L.
Bleske
and
D.M.
Buss
Harris, and Kurzweil (1994) proposed that
such sexual attraction and ambiguity are
challenges or costs of opposite-sex friend-
ship. Some men and women report, how-
ever, that they are valuable additions to
friendship (Bell, 1981; Sapadin, 1988). The
current investigation, guided by a theore-
tical base of evolutionary principles, tests
predictions about differences between
men’s and women’s perceptions
of
how
beneficial or costly sexuality is in opposite-
sex friendships.
Evolutionary approaches to relation-
ships, of which friendship is one type, focus
on the special benefits derived from these
H1:
For men, more than for women, one
function of opposite-sex friendship
is
to
provide sexual access to the opposite sex.
We test this hypothesis with the follow-
ing predictions:
Prediction la:
Men will perceive the poten-
tial for sexual access to an opposite-sex
friend as more beneficial than will
women.
Prediction lb:
Men will report experiencing
unreciprocated attraction toward an
opposite-sex friend more often than
will
women.
relationships. In examining opposite-sex
friendships, the benefits men and women
derive may differ. In posing the question,
“Can men and women be just friends?,”
the answer may not be the same for both
sexes.
Men and women are predicted to differ
psychologically in domains in which they
recurrently faced different adaptive prob-
lems over human evolutionary history, In
the domain of human mating, and
PO-
tentially friendship, several psychological
If
one function
of
opposite-sex friend-
ship is
to
provide men with sexual access to
the opposite sex, men may request sexual
access to their opposite-sex friend more
often than do women, and thus we expect
that men will be denied sexual access to
their opposite-sex friend more often than
will women. Men
are
predicted to perceive
the
failure
to obtain sexual access to their
opposite-sex friend as more costly than will
women.
differences between the sexes may be the
result of a sex difference in minimum
obligatory parental investment. Women
face a minimum investment of 9 months of
gestation, in addition to subsequent lacta-
tion. Men require a mere act
of
sex to pro-
vide opportunity for the passage of their
genes into the next generation; thus, the di-
rect reproductive benefits of gaining sexual
access to a variety of mates would have
been higher for men than for women (Sy-
mons, 1979; Trivers, 1972). In social contexts
in which some short-term matings were
possible, ancestral men who engaged in
short-term sexual encounters with a variety
of women would have been more reproduc-
tively successful, on average, than those an-
cestral men who did not (Buss, 1994). Men
have, therefore, evolved a strong desire for
sexual access to a variety of members of the
opposite sex. The current investigation sug-
gests that opposite-sex friendship may be
one vehicle through which men gain sexual
access. Thus, our first hypothesis is as fol-
lows:
Prediction lc:
Men will report being denied
sexual access to their opposite-sex friend
more often than will women.
Prediction Id:
Men will perceive being de-
nied sexual access to their opposite-sex
friend as more costly than will women.
Hypotheses
2
and
3
also follow from the
logic
of
parental investment. Women, as the
sex with greater obligatory investment,
have recurrently faced the adaptive prob-
lems
of
securing resources and protection
for themselves and their offspring. Over the
course of our evolutionary history, those
women who were able to secure resources
(e.g., food, material goods) and protection
from men would have been more successful
than those women who were unable to se-
cure resources and protection for them and
their potential offspring. Thus, women are
hypothesized to have an evolved opposite-
sex friendship psychology that includes a
preference for friends who are able and
willing to offer them resources and protec-
Friendship
133
tion, or who have future prospects
of
an
ability to offer such benefits.
H2
For women, more than for men, a
func-
tion
of
opposite-sex friendship is to pro-
vide resources.
H3:
For women, more than for men, a fine-
tion
of
opposite-sex friendship is to pro-
vide protection.
We test these hypotheses with the fol-
lowing predictions:
Prediction 2a:
Women will perceive receiv-
ing economic resources, such as cards,
gifis, and paid evenings out,
from
an op-
posite-sex friend as more beneficial than
will men.
If
women have evolved to desire economic
resources from their male friends, the
friendships they preserve should be those
that offer such benefits.
Prediction 2b:
Women will report receiving
economic resources, such as cards, gifts,
and paid evenings out, from an opposite-
sex
friend more often than will men.
Prediction 3a:
Women will perceive receiv-
ing protection
from
an
opposite-sex friend
as more beneficial than will men.
Prediction 3b:
Women will report receiving
protection
from
an opposite-sex friend
more often than will men.
Hypothesis 4 proposes that people’s per-
ceptions of opposite-sex and same-sex
friendships differ. Men and women may per-
ceive opposite-sex friends differently from
same-sex friends in part because opposite-
sex friends are able to provide unique,
“inside” information about the opposite sex
(Bell, 1981; Hacker, 1981; Sapadin, 1988).
Specifically, we propose that opposite-sex
friends may offer information about what
members
of
the opposite sex desire in a mate
and how to attract them.
H4:
For men and women, a function
of
op-
posite-sex friendship, more than
of
same-
sex friendship, is to provide information
about the opposite sex.
Same-sex friends may be less likely than
opposite-sex friends to hold “inside” infor-
mation about the opposite sex. Moreover,
to the degree that same-sex friends do hold
such information, intrasexual rivalry be-
tween them may deter them from sharing it.
If
gaining knowledge about opposite-sex
mating desires has helped men and women
to be more successful at mating, men and
women should perceive such information
as highly beneficial.
We
therefore predict
the following:
Prediction 4a:
Men and women will report
receiving information about the opposite
sex more often from an opposite-sex
friend than from a same-sex friend.
Prediction 4b:
Men and women will perceive
the potential for receiving information
about the opposite sex as more beneficial
from
an opposite-sex friend than from a
same-sex friend.
Preliminary Study: Identifying the
Benefits and Costs
of
Same-Sex
Fkiendships and Opposite-Sex Friendships
The goal of this study was to identify the
range of benefits and costs that men and
women perceive as important in their same-
sex and opposite-sex friendships. Toward
this end, we developed an act nomination
procedure (Buss
&
Craik, 1983), in which
we asked participants to list for us the bene-
fits and costs
of
same-sex friendship and
opposite-sex friendship.
Method
Participants.
Participants were
400
under-
graduates enrolled in a large state university.
The study was completed as a 5-minute, in-
class activity, and thus
no
demographic in-
formation was requested of the participants.
Nomination
of
benefits and costs.
Half of
the participants were asked to think of the
most important same-sex friendship that
they currently had or had had in the past;
half were asked to think of the most impor-
tant opposite-sex friendship. The instruc-
tions were brief Participants were asked to
134
A.L.
Bleske
and
D.M.
Buss
list the
10
most important
benefits
or
advan-
tages
of the friendship for them (one page
of space provided), followed by the
10
most
important
costs
or
disadvantages
(one page
of space provided). Half of the participants
completed the lists in reverse order, that is,
costs before benefits. Participants were
urged to be as specific and thorough as pos-
sible as they made their lists.
Classification
of
benefits and costs.
After a
large and diverse set of benefits and costs
was identified by the participants, the first
author generated a full list
of
benefits and
costs, eliminating redundancies. Then, the
authors and one other researcher inde-
pendently categorized the items. If two out
of three judges agreed, an item was re-
tained in a specific category. To test the hy-
potheses detailed above, the first author
selected several prototypical items from the
relevant categories. Then, the second
author and one other researcher inde-
pendently selected prototypical items from
each of the relevant categories.
If
two
of
three judges agreed on prototypicality, an
item was included on the questionnaire. For
example, three distinct yet related items
were used to test the first prediction under
Hypothesis
1:
(1)
We had sexual inter-
course,
(2)
He (She) let me have sex with
him (her), and
(3)
We had sexual contact
just short of sexual intercourse. Various
items that were unrelated to the current
hypotheses were added to the question-
naire as filler items. The authors limited the
questionnaire list to
100
items for fear of
losing participant interest. Categories for
Hypotheses
1
through
4
were represented
by anywhere between two and five items.
If
only two items comprised a category or
were judged as prototypical
of
a
category,
those two items were used on the question-
naire to represent the category. We did not
generate new items outside of the act nomi-
nation procedure
so
as to ensure an equal
number of items per category; rather, we
used only the act nominations that partici-
pants themselves had generated.
After data collection was complete for
each study, reliability analyses were per-
formed on all categories, for each friend-
ship type. Table
1
lists each category, its
respective items as represented in the ques-
tionnaires, and its alpha reliability coef-
ficients if the category was represented by
more than one item on the questionnaire.
In both studies, all participants responded
to the same items (pronouns were adjusted
to fit the sex of target and actor). Several
items relevant to same-sex friendship, such
as competing for a dating partner, were
included on questionnaires that requested
participants to reflect on an opposite-sex
friendship. Several items relevant to oppo-
site-sex friendship, such as desiring sexual
access to a friend, were included on ques-
tionnaires that requested participants to
reflect on a same-sex friendship. Thus, we
expected participants to perceive some
nominations as irrelevant to their friend-
ship and to respond with the option “Not
Applicable.”
Below
we
describe the methods
of
two
separate empirical studies that succeeded
the act nomination procedure. We consoli-
date the findings
of
the two studies into one
Results section. Study
1
provides a fre-
quency analysis of the nominated benefits
and costs, and Study
2
provides a benefit-
cost analysis
of
the nominated benefits and
costs. The data from Study
1
reflect men’s
and women’s reports of actual behavioral
occurrences
of
benefits and costs in their
closest same-sex and opposite-sex friend-
ships. These behavioral reports are less
closely tied than those of Study
2
to men’s
and women’s evolved friendship psychol-
ogy, and they are best interpreted as com-
plex products of men’s and women’s
evolved desires. The finding that men often
provide their women friends with protec-
tion, for example, is potentially the complex
product
of
men’s desire for sexual access
coupled with women’s preference for a
long-term mate capable of providing pro-
tection.
The data from Study
2
pertain to men’s
and women’s
perceptions
of
how beneficial
and how costly different aspects of friend-
ships would be if they were to occur in a
close friendship. The benefit-cost analysis
Friendship
135
in Study 2 explores whether men and
women perceive certain events in friend-
ship as desirable or undesirable, inde-
pendent of their frequency of occurrence.
Although sexual intercourse may actually
be an infrequent occurrence in opposite-
sex friendship, for example, we predict that
men will perceive the potential for its
occurrence as more beneficial than will
women. As Symons (1979) noted, desire for
a
low-frequency event can evolve if the
event has large fitness consequences.
Study
1:
Perceived Frequency
of
Benefit
and Cost Occurrences in Friendship
The first goal of Study
1
was to test predicted
sex
differences in the reported frequency
of
received benefits in opposite-sex friendship
(Hypotheses
1
through 3). The second goal
was to test predicted
friendship
differences
in the reported frequency of benefit and cost
occurrences (Hypothesis 4).
Method
Participants
One hundred thirty-one fe-
male and 100 male undergraduates, none of
whom had participated in the preliminary
study, served as participants. They ranged
from 17 to 31 years of age, with an average
of
19.24 years. Fifty-five percent of subjects
were Caucasian,
20%
Asian American,
17%
Hispanic,
5%
African American, and
3% “Other” (e.g., American Indian). Par-
ticipants received research credit as a par-
tial requirement for a course in introduc-
tory psychology. The authors dropped the
data from three homosexual participants.
To
maximize sample size, the authors re-
tained the data from three participants who
were unsure of their sexual orientation.
Design.
The design was a
2
X
2 factorial.
The first factor was sex
of
rater (male,
fe-
male), and the second factor was type
of
friendship (same-sex, opposite-sex). Half
of
men and half of women were asked to re-
spond to items about their closest same-sex
friendship. The remaining men and women
were asked to respond to items about their
closest opposite-sex friendship.
Measure.
We constructed a 100-item mea-
sure
to
assess the perceived frequency of
occurrence
of
the benefits and costs (see
Table
1
for a list of items). Items linked to
the hypotheses were randomly distributed
in the questionnaire among other benefit
and cost items that were not relevant
to
the
hypotheses.
Procedure.
Participants were tested in
groups ranging from 2 to 25. First, a short
biographical section asked for participants’
age, sexual orientation, and romantic rela-
tionship status. Second, participants were
asked to give a specific estimate of how
many same-sex and opposite-sex individu-
als during the past year they had considered
to be their close friends. Third, participants
were asked to think
of
their closest or most
important same-sex (opposite-sex) friend
and, keeping that person in mind, evaluate
how often
each of the
100
items were or had
been an aspect of the friendship. Partici-
pants were provided with a 7-point Likert
scale, with
0
=
Never to
6
=
Very often.
Participants were also given the option to
respond with NA
=
“Not Applicable” if
they felt that the test item did not apply to
the target friendship.
Study
2:
Perceived Benefits and
Costs
of
Friendship
The first goal of this study was to test pre-
dicted
sex differences
in perceived benefit
and cost
of
potential qualities of opposite-
sex friendship (Hypotheses
1
through 3).
The second goal of this study was to test
predicted
friendship differences
in per-
ceived benefit and cost of potential quali-
ties
of
friendship (Hypothesis 4).
Method
Participants.
One hundred thirty-seven fe-
male and 92 male undergraduates, none
of
whom had participated in the preliminary
or first study, served as participants. Sub-
Table
1.
Summary
of
categories, their individual items, and reliability coefficients
for
resultant composite variables in Study
1
and Study
2
Study
1
Study
2
(Frequency alpha) (Cosnenefit alpha)
Category Item
SSF
OSF
SSF
OSF
Hypothesis categories
We had sexual contact just short
of
sexual intercourse.
He
let me have sex with him.
We had sexual intercourse.
He wanted to date me, but
I
didn't want to date him.
I
could not reciprocate the romantic feelings he
He
denied me sex.
He refused to have sex with
me.
He bought me gifts.
He paid
for
me
when we went out.
He
ran errands for me.
He
protected me.
I
felt safer in dangerous situations when
I
was with
He
took care
of
me when another guy was being too
He
watched over me in any situation.
He gave
me
good advice about guys.
He
helped me understand the opposite sex.
He told
me
what men want and like in a romantic partner.
He gave me advice
on
how to attract men.
I
got an idea
of
what
guys
want by hanging
out
with him.
He made my boyfriend jealous.
I
felt like
I
had to hide our friendship from
my
boyfriend.
My boyfriend tried to compete with him.
*
.90
.84
.89
*
.&I
.21 .74
*
.79
*
.83
Sexual Accessb
Can't Reciprocate
Denied Sexual AccessC
Attraction' had for me.
)-r
Q\
w
Resource Gainb He gave me flowers and cards
51
.75
.68
.77
Protectionb He walked me to
my
car at night.
.74
.77
.77 .76
him.
sexually aggressive toward
me.
Information About
the Opposite Sexb
.72 .78
.84
.83
Jealousy in
Own
Mate'
.71
.88
$2
.88
Sexual RivalryC
LT
Mate Potentialb
No
LT
Mate Potential‘
CrueYMean BehaviorC
Upward Social
Comparisonc
w
w
4
Lowered Self-worthc
Decreased Social
Status“
Increased Social
Self-Esteem Boostb
Statusb
She flirted
with
my
boyfnend.
She dated a
guy
that
I
liked.
We competed
to
attract men.
There was the possibiIity
of
a future relationship beyond
He was everything
I
could ask for in
a
romantic partner.
He saw
me
as “just a friend.”
He saw me as a friend rather than
as
a romantic partner.
He wanted to be “just friends”
He was condescending toward
me.
He made public jokes at my expense.
He belittled me
in
front
of
others.
He made
fun
of me in public.
I felt physically unattractive
in
comparison to him.
My self-esteem went down when
1
was
with
him because
My
self-esteem went
down
when
1
was around him because
He
made me feel insecure about my
worth.
He
looked
down
on me.
People
thought
I
was
a
bad person because
I
was friends
Others disliked me
because
1
was friends
with
him.
People treated
me
with respect because
I
was
his
friend.
Others
liked
me
because
I
was
his
friend.
He
boosted
my
self-esteem
by
complimenting
me.
My self-esteem went
up
when
I
was
around
him
He
boosted
my
ego.
He made me feel attractive to
the opposite
sex.
He
helped
me
feel more confident
in
romantic relationships.
friendship.
Other
categories
he was
so
physically attractive.
he was
so
popular.
with
him.
because
he
was
so
popular.
-63
*
.74
.86
.81
.61
.50
.70
.79
*
.62
.S8
.72
.70
.67
.68
.59
.74
.77
.60
.67
.90
.82
.88
.79
-70
.77
.89
.74
.87
.86
.87
.8S
.88
.82
-66
Table
1.
(Continued)
Category Item
Study
1
Study
2
(Frequency alpha) (CostlBenefit alpha)
SSF
OSF
SSF OSF
Desirability Assessmentc
Enhanced Mate
Value Appraisalc
Giving ResourcesC
Talk Openlyb
Networkingb
Decreased Mating
Opportunityc
Confusion Over
Relationship StatusC
Taboo Subjectsc
He
told me which men
I
could and could not attract.
He told me which men would like me or not.
He told me
I
deserved better than the guy
I
was with.
He told me my boyfriends weren’t good enough for me.
I
spent a lot
of
money on him.
I
paid for him when we went places.
He could tell me anything.
I
could tell him anything, even things
I
couldn’t tell
We talked about the details of each other’s sex lives.
I
could talk to him about anything.
He could talk about everything and anything with
me.
He
introduced me
to
his friends.
He helped me meet other guys.
He set me up with men.
He arranged for me to go on dates with his friends.
He scared away guys from talking to me.
1
didn’t talk to guys when
I
was around him.
It was harder for me to meet new guys when he was around.
It was difficult to meet his friends because they thought
I
was
He refused to let me date his friends.
I
wanted to date him but didn’t know how he felt about me.
It was hard to determine whether we were going to stay
friends or move on to a romantic relationship.
I
got confused over the status of our relationship.
Our feelings for each other got in the way
of
the friendship.
I
could not discuss other men with him for fear
of
losing him.
I
felt guilty
if
I
talked about other men around him.
my girlfriends.
dating him.
.64 .60 .78 .76
35
.88
.75 .61
.65 .72 .39
.49
.81
.83
.76 .72
.67 .76 .73 .78
.40
.I2
.86 .86
*
*
-79
.67
.81
.67
.81
.46
Jealousy in Friend’s MateC
Sexual Controlb
Annoyance Over No Sex
Dinner Companion
Downward Social
Comparison
Friend Invoked Jealousy
Friend Respected by
Giving Time to Help
Others
Friend
+
Mate-Seeking Partner
w
Mate Stealing
Monetary Favors
Negative Mate Value
Assessment
No Sexual Control
Jealous of Other People
Own Love Not
Reciprocated
Promiscuity
Romantic Involvement
Time Demands
\o
I
made his girlfriend jealous.
His girlfriend got jealous
of
the time
I
spent with him.
His girlfriend paid more attention to him when
I
spent
I
prevented him from having sex with other people.
I
had a say in who he had sex with.
I
kept him from having sex with anyone but me.
a lot of time with him.
.52
.59
Miscellaneous items
from
questionnaire,
with
relevant category label
It annoyed me that he wouldn’t have sex with me.
He went out to dinner with me.
I
felt physically attractive in comparison to
him.
He talked about other girls to make me jealous.
He was respected by other people.
I
gave up my time to help him,
no
matter how busy
I
was.
We went out together to meet men.
She took sexual advantage of my boyfriend while
I
was away.
I
leant him money.
He told me
I
wasn’t good enough for a certain guy.
I
felt like
I
had no control over who he had sex with.
I
was jealous
of
the other girls in his life.
I
was in love with him, but he was not in love with me.
He had sexual intercourse with my friends.
He had a girlfriend.
Our friendship demanded a lot of my time.
.91
.73
.69
.44
.72
.71
Note:
*Reliability analysis was bypassed for scales with variance less than
1.
Reliabilities presented are averaged across the sexes, within each friendship type. In Study
2
reliabili-
ties, (b) in category column represents a benefit reliability, and (c) in category column represents a cost reliability. Items listed in the table are written from a female perspective.
All
items are taken from an opposite-sex friendship survey, except the items within Sexual Rivalry, Mate Seeking Partner, and Mate Stealing which are taken from a same-sex
friendship survey. In the actual study, participants completed surveys with pronouns appropriate to sex
of
rater and sex
of
target friend.
140
A.L.
Bleske
and
D.M.
Buss
jects ranged from 17 to 27 years of age, with
an average of
19.03
years. Seventy-two per-
cent
of
subjects were Caucasian,
13%
Asian
American,
8%
Hispanic,
4%
African
American, and
2%
Pacific Islander. Partici-
pants received research credit as
a
partial
requirement for a course in introductory
psychology. The authors dropped the data
from three homosexual participants and
two bisexual participants; data were re-
tained from three participants who were
unsure of their sexual orientation.
Design.
The
design was a
2
X
2
factorial.
The first factor was sex of rater (male, fe-
male), and the second factor was type of
friendship (same-sex, opposite-sex). Half of
men and half
of
women were asked to re-
spond to items about their closest same-sex
friendship. The remaining half was asked
to
respond to items about their closest oppo-
site-sex friendship.
Measure.
We used the 100-item measure
from Study
1
to assess the perceived benefit
and cost
of
the nominated benefits and
costs (see Table
1).
Items linked to the hy-
potheses were randomly distributed in the
questionnaire among other benefit and cost
items that were not relevant to the hy-
potheses.
Procedure.
Participants were tested in
groups ranging from 2 to
25.
The procedure
was similar to that of Study
1.
In Study
2,
however, participants were asked to think
of their closest or most important same-sex
(opposite-sex) friend and, keeping that per-
son in mind, rate
how beneficial
and
how
costly
each of the
100
items would be if they
were to occur in their friendship. Partici-
pants were provided with two 7-point Lik-
ert scales, one ranging from
0
=
Not at all
beneficial to
6
=
Very beneficial, and the
other from
0
=
Not at all costly to
6
=
Very
costly. Participants were asked to give both
a benefit rating and a cost rating for each
test item. Participants were given the op-
tion to respond with NA
=
“Not Applica-
ble” if they believed the test item did not
apply to the target friendship.
Results: Study
Z
and Study
2
Friendship networks.
Study
1
participants
reported an average of
4.96
close same-sex
friends (range
=
0
to
25),
and
3.70
close
opposite-sex friends (range
=
0
to
20).
Par-
ticipants had significantly more close same-
sex friends than close opposite-sex friends
(t(230)
=
6.04,
p
<
.0001).
Study
2
partici-
pants reported an average
of
6.39
close
same-sex friends (range
=
1
to
44),
and
4.03
close opposite-sex friends (range
=
0
to
20).
Participants had significantly more close
same-sex friends than close opposite-sex
friends
(t(228)
=
7.37,~
<
.0001).
No sex
differences in friendship networks were re-
vealed in either study.
Recoding.
Not applicable (NA) responses
were recoded as zeroes. Any item that par-
ticipants perceived as not applicable to their
friendship was thus interpreted in the data
analysis as an event that never occurred
(Study
l),
or an event that was not at all
costly or not at all beneficial (Study
2).
The
results did not differ significantly when NA
responses were omitted from the analyses.
Reliabilities.
Reliability composites for
Study
1
and Study
2,
for each friendship
type, are displayed in Table
1.
An alpha
level
of
.05
was used for all statistical tests.
Descriptive results.
Table
2
displays the 10
most common qualities
of
same-sex friend-
ship, by category, as reported by men and
women. Table
3
displays the
10
most com-
mon qualities of opposite-sex friendship, by
category, as reported by men and women.
Several qualities of friendship were com-
mon in both men’s and women’s same-sex
and opposite-sex friendships: having a
friend who is respected by others, being able
to talk openly with a friend, having a dinner
companion, receiving a boost to self-esteem
from a friend,providing help to a friend, and
having a friendship that lacks long-term ro-
mantic relationship potential. Other catego-
ries were commonly reported by both men
and women in
sarne-sex
friendships: doing
favors for a friend, having a friend with
Friendrhip
141
Table
2.
Most frequent aspects of same-sex friendship, by category, for men
(n
=
50)
and
for women
(n
=
66)
Men Women
Rank
Category Mean
(SD)
Category Mean
(SD)
1
Friend Respected by Others
2
Talk Openly
3
Romantic Involvement
4
Dinner Companion
5
No LT Mate Potential
6
7
Mate-Seeking Partner
8
Monetary Favors
9
Networking
10
Self-Esteem Boost
Giving Time to Help Friend
4.20 (1.43)
3.87 (1.48)
3.80 (2.03)
3.40 (1.55)
3.30 (2.38)
3.10 (1.64)
2.62 (2.01)
2.28 (1.33)
1.70 (1.17)
2.01 (1.01)
Note:
LT
=
Long-term.
Talk Openly
Friend Respected by Others
Giving Time to Help Friend
Dinner Companion
Romantic Involvement
No LT Mate Potential
Self-Esteem Boost
Mate-Seeking Partner
Networking
Monetary Favors
4.82 (1.03)
3.86 (1.40)
3.74 (1.75)
3.52 (2.19)
2.86 (2.37)
2.62 (1.16)
2.61 (2.04)
2.40 (1.10)
2.24 (1.43)
4.53 (1.22)
whom to meet members of the opposite sex,
having a friend who has a romantic partner,
and
having a friend to introduce them to the
opposite sex. Other categories were com-
mon for both men and women in
opposite-
sex
friendships: Having a friendship with
potential for a long-term romantic relation-
ship, and receiving information about the
opposite sex.
Table
4
displays the
10
most beneficial
qualities
of
same-sex friendship, by cate-
gory, as reported by men and women. Table
5
displays the
10
most beneficial qualities
of
opposite-sex friendship, by category, as re-
ported by men and women. Several quali-
ties of friendship were perceived as highly
beneficial by both men and women in both
same-sex and opposite-sex friendships: hav-
ing a friend who is respected
by
others, be-
ing able to talk openly with a friend, receiv-
ing a boost to self-esteem from a friend,
receiving information about the opposite
sex, having a dinner companion, and provid-
ing help to
a
friend. Having a friend with
whom to meet members of the opposite sex
was perceived as highly beneficial to both
men and women in same-sex friendships.
Gaining social status from being friends
Table
3.
Most frequent aspects of opposite-sex friendship, by category, for men (n
=
50)
and women (n
=
65)
Men Women
Rank Category Mean
(SD)
Category Mean
(SD)
1
Dinner Companion
4.04 (1.78)
Friend Respected by Others
4.46 (1.54)
2
Friend Respected by Others
4.02 (1.55)
Dinner Companion
4.11 (3.32)
3
Talk Openly
4.01 (1.39)
Talk Openly
3.85 (1.38)
4
Giving Time to Help Friend
3.84
(1.77)
Giving Time to Help Friend
3.55 (1.66)
5
No LT Mate Potential
3.06 (2.16)
Protection
3.06 (1.45)
6
Self-Esteem Boost
2.98 (1.11)
Self-Esteem Boost
2.84 (1.27)
7
Information About the
2.87 (1.54)
Information About the
2.83 (1.42)
8
LT Mate Potential
2.77
(1.58)
No LT Mate Potential
2.71 (2.00)
9
Giving Resources
2.66 (1.79)
LT Mate Potential
2.53 (2.12)
10
Time Demands
2.46 (2.00)
Resource Gain
2.35 (1.52)
Note:
LT
=
Long-term.
Opposite Sex Opposite Sex
142
A.L.
Bleske
and
D.M.
Buss
Table
4.
Most beneficial aspects
of
same-sex friendship, by category, as perceived by men
(n
=
46)
and women (n
=
69)
Men Women
Rank Category Mean
(SD)
Category Mean
(SD)
1
2
3
4
5
6
7
8
9
10
Friend Respected by Others
Talk Openly
Mate-Seeking Partner
No
LT Mate Potential
Networking
Self-Esteem Boost
Information About the
Opposite Sex
Increased Social Status
Giving Time to Help Friend
Dinner Companion
4.46 (1.56)
4.26 (1.32)
3.72 (2.06)
3.68 (2.18)
3.13
(1.74)
3.07 (1.67)
2.99 (1.83)
2.75 (2.02)
2.74 (1.89)
2.70 (1.93)
Talk Openly
Friend Respected by Others
Dinner Companion
Giving Time to Help Friend
Mate-Seeking Partner
Protection
No
LT Mate Potential
Self-Esteem Boost
Information About the
Opposite Sex
Networking
4.96 (1.12)
4.67 (1.93)
4.36 (1.54)
4.30 (1.65)
3.87 (2.20)
3.72 (1.51)
3.67 (2.19)
3.51 (1.39)
3.26 (1.45)
3.10 (1.47)
Nore:
LT
=
Long-term.
with someone was perceived as highly bene-
ficial for men in both same-sex and oppo-
site-sex friendships. Receiving protection
was perceived as highly beneficial
for
women in both same-sex and opposite-sex
friendships, and also beneficial for men in
opposite-sex friendships. Having a friend to
introduce them to the opposite sex was per-
ceived as beneficial to men and women in
same-sex friendships, and to women in op-
posite-sex friendships. Receiving resources
was perceived as a beneficial aspect
of
op-
posite-sex friendship
for
both men and
women. All lists, except men’s opposite-sex
friendship, included the
lack
of long-term
mate potential as one of the
10
most benefi-
cial aspects of friendship. The potential
for
a
long-term mateship was perceived as bene-
ficial to men in opposite-sex friendships.
Table
6
displays the
10
most costly as-
pects
of
same-sex friendship, by category,
as
reported by men and women. Table
7
dis-
Table
5.
Most beneficial aspects
of
opposite-sex friendship, by category, as perceived by
men (n
=
46)
and women (n
=
68)
Men Women
Rank Category Mean
(SD)
Category Mean
(SD)
1
Talk Openly
4.37 (1.20)
Dinner Companion
4.75 (1.55)
2
Information About the
4.20 (1.62)
Friend Respected by Others
4.50 (2.03)
3
Self-Esteem Boost
4.08 (1.36)
Protection
4.43 (1.30)
4
Friend Respected by Others
4.04 (1.75)
Talk Openly
4.39 (1.27)
5
Dinner Companion
3.74 (1.86)
Information About the
4.12 (1.53)
6
LT
Mate Potential
3.27 (2.06)
Self-Esteem Boost
3.99 (1.25)
7
Giving Time to Help Friend
3.26 (1.91)
No
LT Mate Potential
3.42 (2.21)
8
Resource Gain
3.21 (1.55)
Resource Gain
3.29 (1.83)
9
Increased Social Status
2.79 (2.13)
Giving Time to Help Friend
3.12 (1.80)
10
Protection
2.67 (1.40)
Networking
2.99 (1.67)
Noie:
LT
=
Long-term.
Opposite Sex
Opposite Sex
Friendship
143
Table
6.
Most costly aspects
of
same-sex friendship, by category, as perceived by men
(n
=
46) and women
(n
=
69)
Men Women
Rank Category Mean
(SD)
Category Mean
(SD)
1
CruelMean Behavior
2.51 (2.03)
Cruel/Mean Behavior
2.59 (2.24)
2
Giving Time to Help Friend
2.35 (1.70)
Lowered Self-worth
2.33 (2.49)
3
Lowered Self-worth
2.22 (2.30)
Negative Mate Value
2.25 (2.42)
4
Monetary Favors
2.20 (2.13)
Sexual Rivalry
2.09 (1.91)
5
Mate Stealing
2.09 (2.80)
Mate Stealing
2.01 (2.68)
6
Time Demands
2.04 (1.91)
Time Demands
1.84 (1.75)
7
Sexual Rivalry
1.99 (1.78)
Giving Time to Help Friend
1.77 (1.59)
8
Jealousy in Own Mate
1.78 (1.95)
Enhanced Mate Value
1.77 (1.70)
9
Negative Mate Value
1.76 (2.21)
Upward Social Comparison
1.77 (1.83)
10
Promiscuity
1.67 (2.24)
Desirability Assessment
1.76 (2.11)
Assessment
Appraisal
Assessment
plays the
10
most costly aspects of opposite-
sex friendship, by category, as reported by
men and women. Several aspects of friend-
ship were perceived as costly by both men
and women in both types of friendships: re-
ceiving cruel or mean behavior from a
friend, providing help to a friend, feelings of
lowered self-worth due to a friend, devoting
time to a friend, and being told by a friend
that he or she is not good enough for a cer-
tain opposite-sex individual. Sexual rivalry
and mate stealing were perceived as costly
to both men and women in same-sex friend-
ships. Being jealous of other people in a
friend’s life, being confused over the
friend-romantic status of the relationship,
and being in love with a friend who does not
reciprocate were perceived as costly to both
men and women in opposite-sex friend-
ships. Lending a friend money, having a
Table
7.
Most costly aspects
of
opposite-sex friendship, by category, as perceived by men
(n
=
46) and women
(n
=
68)
Men Women
Rank Category Mean
(SD)
Category Mean
(SD)
1
2
3
4
5
6
7
8
9
10
Giving Time to Help Friend
Jealous
of
Other People
Confusion Over
Relationship Status
Lowered Self-worth
Own Love Not Reciprocated
Taboo Subjects
Friend Invoked Jealousy
Time Demands
CruelMean Behavior
Negative Mate Value
Assessment
2.96 (1.90)
2.70 (2.20)
2.69 (1.63)
2.51 (2.39)
2.43 (2.66)
2.42 (1.73)
2.41 (2.12)
2.41 (2.09)
2.33 (1.94)
2.33 (2.36)
Jealous
of
Other People
CruelMean Behavior
Giving Time to Help Friend
Confusion Over
Time Demands
Lowered Self-worth
Decreased Mating
Own Love Not Reciprocated
Negative Mate Value
Can’t Reciprocate Attraction
Relationship Status
Opportunity
Assessment
2.75 (2.99)
2.63 (2.24)
2.56 (1.90)
2.54 (1.95)
2.41 (1.89)
2.40
(2.68)
2.34 (1.80)
2.29 (2.61)
2.29 (2.66)
2.28 (2.28)
144
A.L.
Bleske
and
D.M.
Buss
sexually promiscuous friend, and having a
same-sex friend elicit jealousy in their girl-
friends were perceived as costly by men in
same-sex friendships. Being told by a friend
that she deserves better than the man she is
with, feeling physically unattractive in com-
parison to a friend, and being told by a
friend which men she could or could not
attract were perceived as costly by women
in same-sex friendships. Feeling guilty talk-
ing about women with a friend and having a
friend who talks about other men to make
them jealous were perceived as costly to
men in opposite-sex friendships. Decreased
opportunity to meet men when a friend is
around and having a friend toward whom
one cannot reciprocate his romantic inter-
ests were perceived as costly to women in
opposite-sex friendships.
Sexual access
In support of Hypothesis 1,
categorical-level analyses revealed that
men evaluated the potential for having sex
with their close opposite-sex friend as more
beneficial than did women (male
M
=
1.97,
SD
=
2.14;female
M
=
.74,SD
=
1.48;t(73)
=
3.39,~
<
.001,
d
=
.34). This effect was
found for each of the items comprising this
category.
Our second prediction for this hypothe-
sis was that men more often than women
would report experiencing attraction to-
ward their opposite-sex friend with no at-
traction in return. This prediction was indi-
rectly supported. Compared to men, women
more often reported having an opposite-sex
friendship in which their friend was roman-
tically attracted to them but in which they
were not romantically attracted to their
friend (male
M
=
.86,
SD
=
1.38; female
M
=
.24).
Our third prediction was also supported
by the frequency analysis. Men were denied
sexual access to their opposite-sex friends
more often than were women (male
M
=
.65, SD
=
1.43; female
M
=
.03, SD
=
.15;
t(50)
=
3.04,~
<
.01,
d
=
.39). The fourth
prediction was not supported. Men did not
perceive the failure to receive sexual access
to their opposite-sex friend as any more
=
1.68,SD
=
2.06;t(lll)
=
-2.57,~
<
.05,d
costly than did women
(p
=
-33). Both men
and women rated the items associated with
restricted sexual access as relatively low in
cost. In sum, three
of
the four empirical
tests provided moderate support for
Hy-
pothesis
1.
Indirect support for the hypothesis that
sex is perceived as a benefit of opposite-sex
friendship for men more than for women
comes from men’s and women’s reported
frequencies
of
sexual intercourse in their
opposite-sex friendships. Twenty-two per-
cent of men reported that they and their
close opposite-sex friend had had sexual in-
tercourse sometimes or often, whereas
10.8%
of
women reported that they and
their close opposite-sex friend had had sex-
ual intercourse sometimes or often. This re-
sult suggests that men may be more likely
to pursue sex in their friendships. It also
suggests that men may be more likely to
categorize a sex partner as a close friend.
Further indirect support for this hy-
pothesis comes from a correlation between
(a) the frequency with which men reported
that their female friend desired a romantic
relationship with them but they did not de-
sire the same with their friend, and (b) the
frequency with which they reported having
had sex with their friend
(r
=
.64,
p
<
.OOOl).
This correlation was not significant
for women
(r
=
-.13,p
=
.31). The corre-
lation for men was significantly different
from the correlation for women
(z
=
3.24,
p
<
.Ol). This result suggests that men, but
not women, may take advantage
of
the sex-
ual opportunities that might arise when a
friend is sexually attracted to them.
Resource
provisioning.
Hypothesis
2
was
not supported. At the categorical level,
women were not more likely than men to
receive resources from their opposite-sex
friends
0,
=
.38). Because this result was
surprising, we analyzed the category of Re-
source Gain (see Table 1) in further depth
by analyzing each of the individual items.
The item
“He
(She) paid for me when we
went out” showed a pattern different from
the other items. Women received more fre-
quent paid outings from their opposite-sex
Friendship
145
friend than did men (male
M
=
1.74,
SD
=
1.75;
female
M
=
3.14,
SD
=
2.11; t(113)
=
-3.79,~
<
.0001, d
=
.36).
Women received
paid outings from both their opposite-sex
friends
and
same-sex friends more often
than did men (male
M
=
1.43,
SD
=
1.61;
female
M
=
2.35,
SD
=
1.99; F(1, 227)
=
16.21,~
<
.0001;d
=
.26).
The predicted sex difference in per-
ceived benefit of receiving resources from
an opposite-sex friend was not supported at
either the categorica1 level or the individual
item level. Both women and men perceived
it as beneficial to have an opposite-sex
friend who paid for them when they went
out together, who gave them gifts, flowers,
and cards, or who ran errands for them
(category
p
=
30).
Both women and men
perceived the receipt of resources from
their opposite-sex friend as more than mod-
erately beneficial.
Item-level analyses of variance
(ANO-
VAs)
revealed an interaction between sex
and friendship type for perceived benefit of
receiving certain resources. On the one
hand, women perceived it as beneficial to
receive gifts and flowers and cards from
either a same-sex friend (SSF) or opposite-
sex friend
(OSF)
(Gifts
p
=
.75,
Flowers
and cards
p
=
.74).
Men,
on
the other hand,
perceived it as more than somewhat bene-
ficial to receive gifts, flowers, or cards from
an opposite-sex friend, but less than some-
what beneficial to receive such benefits
from a same-sex friend (Gifts:
OSF
M
=
3.85,
SD
=
1.89;
SSF
M
=
1.83,
SD
=
1.99;
t(90)
=
5.00,~
<
.0001,
d
=
.52.
Flowers and
cards:
OSF
M
=
3.02,
SD
=
2.28;
SSF
M
=
.20,
SD
=
23; t(56)
=
7.91,~
<
.0001,
d
=
.91).
Both men and women perceived it as
more beneficial to receive a paid night out
from their opposite-sex friends than from
their same-sex friends
(OSF
M
=
3.04,
SD
=
2.23;
SSF
M
=
1.57,
SD
=
1.97; t(227)
=
5.26,
p
<
.0001,
d
=
.28).
Protection.
In support of Hypothesis
3,
the
frequency analysis suggested that women
received protection from their opposite-sex
friends more often than did men (male
M
=
1.65,
SD
=
1.23;
female
M
=
3.06,
SD
=
1.45; t(113)
=
-5.49,
p
<
.0001, d
=
.53).
Four of the five Protection items displayed
this effect. Women’s opposite-sex friends
protected them, walked them to their car at
night, and watched over them in any situ-
ation more often than did men’s opposite-
sex friends. Women also reported feeling
safe in dangerous situations when with their
opposite-sex friend more often than did
men. Both sexes, however, rated one item,
“He(She) took care
of
me when another
guy(gir1) was being too sexually aggressive
toward me,” as an infrequent event in their
opposite-sex friendship (male
M
=
.78,
fe-
male
M
=
1.17,~
=
.24).
The benefit-cost analysis supported Hy-
pothesis
3.
Women evaluated the potential
for receiving protection from an opposite-
sex friend as
more
beneficial than did men
(male
M
=
2.67,
SD
=
1.40;
female
M
=
d
=
.65).
This effect held for all individual
items in the Protection category. The mag-
nitude of the sex difference in perceptions
of protection is also apparent from the lists
of the
10
most beneficial aspects of oppo-
site-sex friendship (see Table
5),
in which
protection ranks third for women and tenth
for men. In sum, men’s and women’s per-
ceptions of receiving protection from an
opposite-sex friend differ in the predicted
direction in all relevant tests. Importantly,
men evaluated the potential for having a
friend walk them home at night or take care
of them if another female was being sexu-
ally aggressive as more beneficial when the
protection came from an opposite-sex
friend than from a same-sex friend (Walk
home:
OSF
M
=
2.37,
SD
=
2.24;
SSF
M
=
1.13,
SD
=
1.86; t(87)
=
2.89,~
<
.01, d
=
.30.
Protect from sexual aggressor:
OSF
M
=
2.33,
SD
=
2.13;
SSF
M
=
.59,
SD
=
1.33;
475)
=
4.70,~
<
.0001,d
=
SO).
Women also received protection from
their
sume-sex
friends more often than did
men (male
M
=
1.14,
SD
=
1.04;
female
M
=
2.08,
SD
=
1.28; (113)
=
-4.38,
p
<
.0001,
d
=
.65)
and perceived the potential
for receiving protection from a
same-sex
friend as more beneficial than did men
(male
M
=
2.07,
SD
=
1.40;
female
M
=
4.43,
SD
=
1.30; (112)
=
-6.88,~
<
.OOOl,
146
A.
L.
Bleske
and
D.
M.
Buss
3.72,
SD
=
1.51;
t(113)
=
-5.91,~
<
.0001,
d
=
S7).
Hence, regardless of the sex of the
friend who offered protection, women per-
ceived protection as more beneficial (male
M
=
2.37,
SD
=
1.43;
female
M
=
4.07,
SD
=
1.45;
F(1,225)
=
-81.02,~
<
.0001,
d
=
S9).
In sum, protection appears to be a
benefit women receive from both same-sex
and opposite-sex friends.
Information about the opposite sex.
In sup-
port of Hypothesis
4,
men and women re-
ceived advice about opposite-sex mating de-
sires from their opposite-sex friends more
often than from their same-sex friends (OSF
M
=
2.85,
SD
=
1.47;
SSF
M
=
1.88,
SD
=
1.09; f(209)
=
5.66,~
<
.0001,
d
=
.62).
Men
and women also reported that receiving in-
formation about the opposite sex from an
opposite-sex friend was more beneficial
than receiving such information from a
same-sex friend
(OSF
M
=
4.15,
SD
=
1.56;
SSF
M
=
3.15,
SD
=
1.61; t(227)
=
4.78,~
<
.0001,
d
=
.32).
For both men and women,
gaining information about the opposite sex
ranked among the top
5
most beneficial as-
pects of
opposite-sex
friendship, and among
the top
10
most beneficial aspects of
same-
sex
friendship. In sum, the information
benefit of friendship appears to be sup-
ported across all relevant empirical tests.
Other findings that support
a
link between
friendship and mating.
Several other re-
sults suggested that same-sex and opposite-
sex friendships may facilitate men’s and
women’s mating strategies. Men and women
reported that their same-sex friends fre-
quently provi.ded them with the benefit of
“Networking,” people through whom they
could be introduced to other members of
the opposite sex (see Table
2).
Another fre-
quent benefit of same-sex friendships was
having a friend with whom to go out and
meet members of the opposite sex. This
benefit fell in the top five most beneficial
aspects of same-sex friendship for both men
and women (see Table
4).
Men and women reported that some-
times their opposite-sex friendships had po-
tential for becoming a long-term romantic
relationship (see Table
3).
The sexes dif-
fered, however, in their pursuit of a long-
term romantic relationship in opposite-sex
friendship. For men (see Table
5)
the poten-
tial for a romantic relationship with their
friend ranked
6th
in their list
of
top benefits,
whereas the
lack
of romantic potential did
not make the list. For women, the
lack
of
potential for a romantic relationship with
their opposite-sex friend ranked
7th
in their
list
of
top benefits, whereas the potential
for
a romantic relationship did not make the
list (Table
5).
Other results suggested that friendships
can interfere with men’s and women’s mat-
ing strategies. Both men and women re-
ported that competition to attract members
of the opposite sex was a costly aspect
of
same-sex friendship (see Table
6).
They also
reported that costs
of
opposite-sex friend-
ship included feeling jealous of their friend’s
other opposite-sex friends, feeling confused
over the status
of
their relationship, and hav-
ing their own love
not
reciprocated (see Ta-
ble
7).
For women, a decreased ability to
meet other men when their opposite-sex
friend was around ranked among the top
10
costs
of
opposite-sex friendship (Table
7).
Finally, men and women perceived it as
more costly
(M
=
1.70,
SD
=
1.56)
than
beneficial
(M
=
.75,
SD
=
.98)
to have an
opposite-sex friend evoke jealousy in their
romantic partner (paired
t(233)
=
9.48,~
<
-0001,
d
=
.37),
suggesting that opposite-sex
friendships may lead to conflict in men’s and
women’s romantic relationships (Table
7).
These findings may help to clarify why
men and women tend to have more same-
sex friends than opposite-sex friends. Al-
though opposite-sex friendships can offer a
number of direct benefits, they carry costs.
Opposite-sex friends are less likely than
same-sex friends to introduce each other
to members of the opposite sex and are
less likely to go out together to meet poten-
tial mates. Moreover, opposite-sex friends
sometimes report feeling unreciprocated
attraction, confusion over the status of their
relationship, and jealousy toward each
other’s other opposite-sex friends. Such
costs rarely arise in same-sex friendships.
Friendship
147
Discussion
Benefits and costs
of
friendship
The current studies suggest that same-sex
friendships and opposite-sex friendships of-
fer several common benefits. These benefits
include having
a
respected friend, being able
to talk openly with a friend, receiving a
boost to self-esteem, receiving information
about the opposite sex, and having a com-
panion. Same-sex friendships and opposite-
sex friendships also entail common costs,
such as being treated with cruelty, being ob-
ligated to help a friend, feeling low in self-
worth due to a friend, having one’s time de-
manded, and being told by a friend that one
is not good enough for a certain mate. These
aspects of friendship, common to both men
and women in same-sex and opposite-sex
friendship contexts, replicate and extend
findings from previous work on costs and
benefits of friendship (e.g., Argyle
&
Furn-
ham, 1983; Davis
&
Todd, 1985; Hays, 1988;
Rusbult, 1980; see Fehr, 1996, for a review).
These results suggest that, in many domains,
men and women experience friendship simi-
larly. It is in light of these similarities that the
sex and friendship differences stand out.
Sexual access.
We hypothesized that for
men more than for women one function
of
opposite-sex friendship is to provide sexual
access
to
the opposite sex. Men do perceive
the potential for gaining sexual access to
their opposite-sex friends as more benefi-
cial than do women-the most critical test
of the hypothesis. Other support for Hy-
pothesis
1
comes from our finding that men
who reported that their friend was attracted
to them and that they were unable to recip-
rocate the attraction were also more likely
to report that they had had sex with their
friend. This finding suggests that men may
take advantage of opportunities to have sex
with a female friend, even if they are not
attracted to her.
Men also reported being denied sexual
access to their opposite-sex friends more
often than did women, although twice as
many men as women also reported that
they had had sex with their friend. It is rea-
sonable to infer that men report being de-
nied sexual access to their opposite-sex
friends more often simply because they re-
quest sexual access to their opposite-sex
friends more often.
Despite support for our hypothesized sex
difference, sex is clearly not the only moti-
vator for men. For example, men rated com-
panionship, self-disclosure, and gaining in-
formation about the opposite sex as higher
in benefit than sex.
One finding failed to support Hypothesis
1-women and men in Study
2
did not differ
in their perceptions of how costly it would
be
to
be denied sexual access
to
an oppo-
site-sex friend. Both men and women per-
ceived the potential for rejection as rela-
tively
low
in cost. Two factors might explain
why men overall did not perceive sexual re-
jection as more costly than did women. First,
the costs to men of initiating sexual encoun-
ters are low, particularly when compared to
the benefits they reap when their initiations
are accepted. For women, the
benefits
of en-
gaging in a short-term sexual encounter
may be low, particularly when compared to
the potential costs-reputational damage,
pregnancy without an investing father, or
abuse from a jealous mate
(Buss,
1994; Buss
&
Shackelford, 1997). Women might there-
fore be
less
likely than men to initiate short-
term sexual encounters with an opposite-
sex friend.
Second, when selecting a short-term sex
partner, men’s threshold of acceptance for
physical attractiveness lowers substantially
(Buss
&
Schmitt, 1993; Kenrick, Sadalla,
Groth,
&
Trost, 1990). Given that men initi-
ate sexual encounters more often, and have
a lower threshold of acceptance for short-
term sex partners, women
should
perceive
it as costly to be rejected. Not only might
they suffer reputational damage and other
costs due to their initiation of the sexual
encounter, they might also perceive the re-
jection as a negative appraisal of their de-
sirability as a
sex
partner.
The results
of
this investigation suggest
that, relative to women, men also perceive
the potential for a long-term romantic rela-
148
A.
L.
Bleske
and
D.M.
Buss
tionship with their friend, which may in-
clude sexual access, as a benefit. Although
both men and women reported that the po-
tential for a romantic relationship some-
times occurs in their opposite-sex friend-
ships, the potential for romance ranked
among men’s
10
most beneficial aspects
of
opposite-sex friendships, whereas the luck
of romantic potential ranked among
women’s 10 most beneficial aspects of op-
posite-sex friendships. Although our origi-
nal hypothesis implied that men might be
interested in short-term sex, the data sug-
gest that men may perceive short-term
or
long-term mateship potential as more bene-
ficial than do women. Future work using the
Sociosexuality Orientation Inventory (SOI;
Simpson
&
Gangestad, 1991) might clarify
individual differences in perceptions of
long-term and short-term mateship benefits
of opposite-sex friendship.
Alternative explanations could account
for the sex difference in perceived benefit of
sexual access in friendship. One explanation
might be that men have a heightened desire
for sexual access that operates across con-
texts, and thus leads men to desire sexual
access from their opposite-sex friends. For
example,it may be that men are socialized to
“oversexualize” the world (Abbey, 1991;
Monsour, 1997; Werking, 1997a), including
their opposite-sex friends (but see Haselton
&
Buss,
2000).
If true, these explanations
raise the following questions: Why are men
more than women socialized to sexualize
their relationships with the opposite sex?
Why do men who are not sexually attracted
to their female friends report having had sex
with them? If men are socialized to perceive
members of the opposite sex as potential sex
partners (and women socialized to perceive
them as potential marriage partners), why
do men in the current investigation judge
the potential for a long-term romantic rela-
tionship with their friend as more beneficial
than women
do?
To
our knowledge, sociali-
zation theories do not offer complete expla-
nations for these questions.
Resource
provisioning.
The current series
of studies does not provide support for the
hypothesized resource function of oppo-
site-sex friendship for women. Women did
not receive flowers, cards, or gifts from their
opposite-sex friends any more often than
did men, although they did receive paid
outings from their friends more often.
Women did not perceive the receipt
of
re-
sources from their opposite-sex friends as
more beneficial; rather, both sexes per-
ceived the receipt of such resources from an
opposite-sex friend as very beneficial.
One explanation for the failure of this
hypothesis may rest with the similar eco-
nomic status of our samples-college stu-
dents with little
or
no income.
In
the typical
college population, both men and women
believe they are in economic need and, thus,
both men and women may perceive it as
beneficial to receive material resources
from others. Alternatively, the provision of
material resources might not be a sex-
linked benefit of friendship. Future research
might test these alternatives by using a sam-
ple
of
young adults with variable incomes.
Protection.
In support
of
Hypothesis
3,
women in
our
sample perceived the poten-
tial for receiving protection from their op-
posite-sex friends as more beneficial than
did men. They also reported receiving pro-
tection from their opposite-sex friends
more often. Women, however, viewed pro-
tection as highly beneficial regardless of
who offered it. It is unclear whether women
would perceive protection as a cue to mate
potential if provided by an opposite-sex
friend, although comparative evidence sug-
gests males who offer protection are more
likely to receive sexual access. In baboons,
females form long-lasting “special friend-
ships” with males from whom they receive
protection and feeding ground. In return,
these females offer occasional sexual access
(Smuts, 1985). Future studies could inves-
tigate the protection function
of
opposite-
sex friendship in humans by determining
whether friendships that provide protection
are more likely than friendships that do not
to develop into short-term
or
long-term
mateships.
Men perceived it as more beneficial to
Friendship
149
have a female friend walk them to their car
or protect them from a sexually aggressive
person than to have a male friend perform
such acts. It
is
possible that men read items
such as
“He
(She) walked me to my car
at
night” to imply
a
romantic interest or emo-
tional protection (e.g., companionship)
from their friend, rather than physical pro-
tection.
To
avoid confounding emotional
and physical protection, as well as romantic
interest, future studies should investigate
actions that clearly imply physical protec-
tion, actions that clearly imply emotional
protection, and actions that clearly imply
romantic interest.
Znformation about the opposite sex.
Men
and women both reported receiving infor-
mation about the opposite sex, such as how
to attract the opposite sex, from both same-
sex friends and opposite-sex friends, but
more
so
from opposite-sex friends. They
also evaluated it as more beneficial to re-
ceive information about the opposite sex
from an opposite-sex friend than from a
same-sex friend. The present studies thus
support the hypothesis that a benefit of op-
posite-sex friendship is to provide informa-
tion about the opposite sex. Members
of
the opposite sex are likely to have more
abundant, and more accurate, information
to offer.
Compatibility with other theories of
general relationship functioning
The predictions tested in these studies were
generated
a
priori from an evolutionary psy-
chological perspective. Alternative theories
of interpersonal relationships, such as inter-
dependence theory (Rusbult, 1980; Rusbult
&
Buunk, 1993) and the theory of commu-
nal and exchange relationships (Clark
&
Mills, 1979), are theories of
general
relation-
ship functioning. The current evolutionary
perspective acknowledges the importance
of exchange in friendship (Cosmides, 1989,
Kenrick
&
Trostt, 1997; Trivers, 1971), and
thus is compatible with these theories. The
general theories, however, tend not to spec-
ify what value people assign to particular
commodities of exchange, nor how these
commodities might be differentially valued
by men and women. An evolutionary per-
spective
on
friendship contributes by mak-
ing specific predictions about the benefits
and costs in particular relationship contexts
and how these benefits and costs might be
differentially valued by men and women.
Methodological concerns and directions
for future research
The current research carries several impor-
tant limitations. First, the research deals
with self-reports of benefits received from
friends as well as perceptions of how bene-
ficial various items are judged to be.
Al-
though this is a reasonable first step in this
largely unexplored domain, future research
could use alternative data sources, such as
observer reports, to verify the patterns
of
results discovered here. Second, the current
studies used undergraduate participants,
who may not be representative of men and
women more generally. And third, the cur-
rent studies explore only a single culture.
Future studies could explore other cultures,
other age groups, and noncollege samples
to determine the generality of the results
found in the current studies.
A sample of older, mated individuals, for
example, might offer new insights into the
psychology of friendship. It is important to
determine whether the benefits of oppo-
site-sex friendship found in the current
samples, such as sexual access and advice
about the opposite
sex,
apply to people who
are involved in a committed romantic rela-
tionship. The costs
of
opposite-sex friend-
ships discovered in the current studies, such
as unreciprocated attraction and confusion
over relationship status, may be even more
costly to mated men and women. If these
speculations are correct, they may partially
explain the decrease in people’s number
of opposite-sex friends upon marriage
(Adams
&
Blieszner, 1995; see Werking,
1997b, for a review).
Future studies could also examine
whether people’s perceptions of their close
same-sex and opposite-sex friendships dif-
150
A.
L.
Bleske
and
D.M.
Buss
fer from their perceptions of their casual
friendships. We suspect that people per-
ceive their casual friendships as lacking
some of the benefits found in close friend-
ships, such as having a mate-seeking part-
ner, a person to confide in, and a person
who offers advice about how to attract the
opposite sex. Moreover, some potential
costs of same-sex friendships, such as com-
petition for mates, may occur more fre-
quently between casual same-sex friends.
hypothesis proposed that opposite-sex
friendships evolved to solve the adaptive
problems men and women have faced over
evolutionary history. This hypothesis im-
plies that opposite-sex friendships were a
common feature of human ancestral envi-
ronments. It requires that the benefits of en-
gaging in opposite-sex friendships,
on
aver-
age, exceeded the costs. If these benefits of
friendship had net reproductive payoffs
over human evolutionary history, then a
psychology of opposite-sex friendship could
have evolved.
Evidence for evolved design for oppo-
site-sex friendships ideally should include
Is
there an evolved opposite-sex friendship
psychology?
Results of the current investigation are con-
sistent with the hypothesis that men and
women have an evolved opposite-sex
friendship psychology. According to this hy-
pothesis, opposite-sex friendship may be an
evolved strategy by which men have gained
sex, women have gained protection, and
both sexes have gained information about
the opposite sex. The hypothesis that some-
thing is a proper function
of
opposite-sex
friendship carries a conceptual implication
that opposite-sex friendship evolved in part
because it contributed to the solution to a
particular adaptive problem that was faced
recurrently over human evolutionary his-
tory.
An alternative explanation is that the
benefits derived from opposite-sex friend-
ships are by-products
of
other evolved
psychological mechanisms. Men’s greater
perceived benefit of sex with opposite-sex
friends, for example, may be
a
by-product of
their evolved desire for sexual variety. Ac-
cording to this explanation, men’s desire for
sex with opposite-sex friends is a novel
application
of
an already existing adapta-
tion-their evolved desire for sexual vari-
ety.
In the current investigation, our initial
answers to these questions:
(1)
Do
men and
women desire friends who can offer the
relevant benefit?
(2)
Do
they select friends
preferentially using this criterion?
(3)
Do
they feel more invested in friends who pro-
vide this benefit?
(4)
Do
they feel dissatis-
fied with and break off friendships that fail
to provide this benefit when the situation
calls for it?
(5)
Do
they perceive this as an
important benefit derived from friendship?
(6)
Do
the sexes differ in the predicted
ways in their perceptions of the importance
of this benefit?
(7)
Do
the above design
features show cross-cultural universality?
Finally, the current studies provide evi-
dence bearing
on
only some of these
standards, such as perceptions of benefit,
frequency of receiving benefit, and sex dif-
ferences in perceptions of benefit and re-
ported frequencies. Future studies must
determine whether sexual access and pro-
tection are evolved functions of friendship
for men and women, respectively, or
whether these perceived benefits are a by-
product of men’s and women’s evolved
mating desires. Can men and women be just
friends? The answer appears to depend
on
the sex of the person you ask.
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... (Afifi & Faulkner, 2000;Bleske & Buss, 2000;Kaplan & Keys, 1997;O'Meara, 1989;Reeder, 2000;Rose, 1985;Swain, 1992).The idea that mating psychology may drive OSF preferences has been advanced by Lewis et al. (2011Lewis et al. ( , 2012 who have provided empirical evidence for the mating activation hypothesis (Lewis et al., 2012). Indeed, they showed that there is a close parallel between OSF preferences and mate preferences, as men prioritized physical attractiveness of their OSFs, while women prioritized their male friends' ability to provide protection and economic resources (Lewis et al., 2011;see Walter et al., 2020). ...
... However, if natural selection has shaped psychological mechanisms that motivate individuals to seek friendships, then we should expect a strategic search for specific friends, which additionally should be different for women and men. Indeed, studies indicate that forming an OSF can be a strategy to gain shortterm sexual access to the opposite sex, to gain protection, as well as to gain long-term mates, or back-up mates (Bleske & Buss, 2000;Bleske-Rechek et al., 2012;Bleske-Rechek & Buss, 2001;Buss & Schmitt, 1993;Lewis et al., 2011Lewis et al., , 2012. ...
... Evolutionary theorists claim that attraction and genderspecific preferences in OSF have functional underpinnings (Bleske & Buss, 2000;Bleske-Rechek et al., 2012;Koenig et al., 2007;Lewis et al., 2011). On the one side, it could be that selection has sculpted psychological mechanisms designed for men and women to seek specific OSFs, and then maintain or terminate such relationships (Bleske-Rechek et al., 2012). ...
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The fact that men and women experience sexual attraction toward their opposite-sex friends has been evidenced in various studies. It has also been shown that there is a close parallel between preferences for opposite-sex friends and mate preferences, i.e., that men prioritize physical attractiveness of their OSFs, while women prioritize their male friends’ ability to provide protection and economic resources. Although this mating activation hypothesis has been validated to an extent, there is hardly any research that points to moderating factors which would define the boundary conditions for these effects. We present two studies that involved heterosexual participants who were in a committed relationship and at the same time had a heterosexual opposite-sex friend. We investigated how both the qualities of one’s current partner and the qualities of one’s opposite-sex friend shape sexual interest in opposite-sex friends for men and women. Results mostly support the mating activation hypothesis. We show that within actual cross-sex friendships: 1) physical attractiveness of opposite-sex friends predicts sexual interest toward them, and this effect is stronger for men than women, 2) current partner’s attractiveness, provided support, and relationship satisfaction moderate this effect only for women, and not men, 3) perceived financial resources of opposite-sex friends predict sexual interest toward them for highly sexually unrestricted women, and, surprisingly, for those who are in committed relationships with high-income men. The results reaffirm previous evidence indicating that perceptions of opposite-sex friends can be viewed as a manifestation of evolved human mating strategies.
... Third, physical attraction to the opposite sex is considered a strong influence of cross-sex friendships (Afifi & Faulkner, 2000;Bleske & Buss, 2000;Bleske-Rechek et al., 2012;Halatsis & Christakis, 2009;Reeder, 2000). The aforementioned studies have supported the assumption that feelings of physical attraction in cross-sex friendships tend to be higher for men than for women. ...
... The aforementioned studies have supported the assumption that feelings of physical attraction in cross-sex friendships tend to be higher for men than for women. Findings by Bleske-Rechek and colleagues (Bleske & Buss, 2000;Bleske-Rechek et al., 2012) have also shown that the costs of physical attraction are usually considered greater than the benefits by both women and men alike. Thus, a greater individual tendency to feel physically attracted to one's cross-sex friends may be associated with greater tension and conflict within one's cross-sex friendship dyads. ...
... The second determinant in this domain was the tendency to feel physically attracted to one's close cross-sex friends. This finding was expected and is in line with previous research (especially Bleske & Buss, 2000;Bleske-Rechek et al., 2012) that stated that physical attraction is subjectively associated with greater costs than benefits. Consistently, individuals who avoid cross-sex friendships reported more of a tendency to feel physically attracted to their cross-sex friends in the present study. ...
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Prior studies on individual differences in the preference for cross-sex friendships found that this preference was not normally distributed but was instead bimodal. In one group of people, the preferences for higher or lower proportions of cross-sex friendships appear to be normally distributed, whereas in a second and unexpectedly large group of people, the preference for cross-sex friends is exactly zero. If the people in the second group with no cross-sex friends at all actively avoid forming cross-sex friendships, then these individuals may be expected to differ systematically and meaningfully from individuals who report having at least one cross-sex friend. The present study tests this hypothesis. The Big Five, homophobia, physical attraction to the opposite sex, and demographic variables from a data set of 491 adult participants were used as potential predictors of group membership. Results showed that most predictors except the Big Five contributed to supporting the separability of the two groups. Findings are discussed with regard to the differentiation between close and general friends and the potential influence of cultural factors.