by the way, i am not strongly defending bailey. i think that we agree, it's inconclusive.

here's the paper if anyone is interested...



Although bisexual behavior is not uncommon in men, there has
long been skepticismthat it is motivated by strong sexual arousal
and attraction to both sexes. For example, the case studies of
Krafft-Ebing (1886) suggest that most men with bisexual activity
have sex with women because of social pressure but have sexual
attraction exclusively or almost exclusively to men (Cases 127,
128, 135–153, and 167). Hirschfeld (1914/2001, pp. 197–215)
speculated that most self-identified bisexual men are either
heterosexual or homosexual and that men with substantial bisexual
attractions are rare. Freund, who was a pioneer in measuring
male genital arousal, wrote that, after assessing genital
arousal in hundreds of men, he never found convincing evidence
that bisexual arousal patterns exist (1974, p. 39).The existence of
male bisexual attraction and arousal remains controversial and
poorly understood (Fox, 2000; MacDonald, 2000; Zinik, 2000).

BISEXUALITY: BEHAVIOR, IDENTITY, AND AROUSAL

Sexual orientation refers to the degree of sexual attraction, fantasy,
and arousal that one experiences for members of the opposite
sex, the same sex, or both. Men’s self-reported sexual
orientation tends to be bimodal, with the large majority reporting
exclusive sexual attraction to women and a minority reporting
exclusive or near-exclusive attraction to men; the number of men
who report substantial sexual attraction to both men and women
is even smaller (Bailey, Dunne,&Martin, 2000; Diamond, 1993;
Laumann, Gagnon, Michael, & Michaels, 1994).
Patterns of sexual behavior (i.e., sexual contact with men or
women) are certainly influenced by sexual orientation, but may
diverge from it for various reasons, including limitations in opportunity
(e.g., imprisoned men without access to women), stigmatization
(typically against homosexuality), or material reasons,
as in the case of prostitution (Gagnon, Greenblat, & Kimmel,
1999). Unquestionably, during the course of their lives, some
men have sex with both men and women. One survey of homosexual
men found that about 69% had also been sexually active
with women (Bell, Weinberg, & Hammersmith, 1981). Furthermore,
some imprisoned men say that they are heterosexual even
though they engage in homosexual sex (Kirkham, 2000). Given
these discrepancies between reported sexual orientation and
sexual behavior in some men, it is reasonable to ask whether
male bisexual behavior reflects sexual arousal to both sexes.
Sexual identity refers to labels, including ‘‘homosexual,’’
‘‘heterosexual,’’ or ‘‘bisexual,’’ that individuals often give themselves
(Sell, 1997). In a national survey, 0.8% of American men
identified as bisexual (Laumann et al., 1994). There may be
varied reasons why some men adopt a bisexual identity. For example,
they may have intense sexual attraction to both men and
women, or they might have sex partners of both sexes. Furthermore,
men who adopt a homosexual identity might go through a
stage in which they consider themselves bisexual. In one study,
up to 40% of homosexual men defined themselves as bisexual
before adopting a gay identity (Lever, 1994). In another study,
most bisexual men shifted over time toward homosexuality;
however, a small number shifted toward heterosexuality (Stokes,
Damon, & McKirnan, 1997). This suggests that some bisexually
identified men might have homosexual feelings (i.e., substantial
attraction and arousal only to men), whereas others might have
heterosexual feelings (i.e., substantial attraction and arousal
only to women).

In terms of behavior and identity, bisexual men clearly exist.
Skepticism about male bisexualitymust therefore concern claims
about bisexual feelings, that is, strong sexual attraction and
arousal to both sexes. The primary methodological challenge for
investigating this issue is to employ a measure of sexual feelings
that does not depend on self-report. At present, this is possible
only for genital sexual arousal.

MEASURING MALE SEXUAL AROUSAL

Male genital arousal can be measured using a circumferential
strain gauge that reflects the changes in penile girth during
erection (Janssen, 2002). Homosexual men show substantially
more genital arousal to sexual stimuli depicting men(male sexual
stimuli) than to those depicting women (female sexual stimuli);
heterosexual men have the opposite pattern (Chivers, Rieger,
Latty, & Bailey, 2004; Freund, 1963; Freund,Watson, & Rienzo,
1989; Sakheim,Barlow, Beck,&Abrahamson, 1985). Subjective
sexual arousal is measured by self-report and is typically highly
correlated with genital arousal in men (Sakheim et al., 1985).
However, when self-report is suspect, genital arousal may
provide a more valid measure. For example, genital arousal
to stimuli depicting children is an effective method of assessing
pedophilia, even among men who deny attraction to children
(Blanchard, Klassen, Dickey, Kuban, & Blak, 2001).
Few studies have investigated genital arousal among bisexual
men. One study (McConaghy & Blaszczynski, 1991) measured
genital sexual arousal to slides of nude men and women in 20men
with problematic sexual preferences (e.g., pedophilia, exhibitionism,
bondage, and fetishism). The authors reported that the
bisexual-identified men among their sample showed bisexual
arousal. However, because of the heterogeneous study sample,
and because the authors did not use rigorous statistical analyses
to distinguish bisexual arousal from heterosexual or homosexual
arousal, the study does not definitively demonstrate that bisexual
men have bisexual arousal. Another study compared the genital
arousal to male and female stimuli of 10 heterosexual, 10 bisexual,
and 10 homosexual men (Tollison, Adams, & Tollison,
1979). Bisexual-identified men were indistinguishable from
homosexual-identified men in their patterns of genital arousal.
However, the group sizes in this study were relatively small, and
thus the study may have lacked power to detect differences between
the two groups.

THE CURRENT STUDY

We recruited self-identified heterosexual, bisexual, and homosexual
men and assessed their genital and self-reported sexual
arousal to male and female sexual stimuli. Our analyses investigated
three hypotheses:

Bisexual men are substantially aroused by both male and female
stimuli.

Bisexual men, like homosexual men, are much more aroused by
male than by female stimuli.
Bisexual men show a mixture of homosexual and heterosexual
patterns of sexual arousal, with some having much more arousal to
male stimuli and others havingmuch more arousal to female stimuli.
Note that these hypotheses are not mutually exclusive.

METHOD

Participants
We advertised in gay-oriented magazines and an alternative
newspaper in Chicago for ‘‘heterosexual,’’ ‘‘bisexual,’’ and ‘‘gay’’
men for a paid study of sexual arousal. Men who called the lab
were asked about their sexual attraction toward men and women,
so that their sexual orientation could be determined (see Measures
and Procedure). Participants included 30 heterosexual
men, 33 bisexual men, and 38 homosexual men, categorized on
the basis of their answers to those questions. We also asked
men to describe their sexual identity as straight, bisexual, or
gay. Sexual attraction and sexual identity (converted to a numeric
3-point scale) were highly correlated, r 5 .95. Mean ages
(standard deviations in parentheses) were 31.6 (5.9), 31.2 (5.4),
and 30.6 (5.8), for the heterosexual, bisexual, and homosexual
men, respectively. The percentage of Caucasian participants was
49.3, and this percentagedidnot vary significantly across groups.
The heterosexual and homosexual participants were included in
an earlier study (Chivers et al., 2004).

Measures and Procedure
The measures and procedure of this study were identical to those
of our earlier study (Chivers et al., 2004), and the report of that
study provides more detail.

Sexual Orientation
Sexual orientation was assessed via self-report using the Kinsey
Sexual Attraction Scale (Kinsey, Pomeroy, & Martin, 1948).
Participants provided separate Kinsey ratings for their sexual
orientation during the past year and during adulthood. The mean
of these two ratings was used in all analyses. ‘‘Heterosexual
men’’ were defined as men with Kinsey Attraction scores less
than or equal to 1, ‘‘bisexual men’’ had Kinsey Attraction scores
greater than 1 and less than 5, and ‘‘homosexualmen’’ had Kinsey
scores greater than or equal to 5.

Stimuli
Participants viewed an 11-min, neutral, relaxing film (e.g.,
landscapes), followed by several 2-min sexual films, and another
neutral film. Two of the sexual films depicted two men having sex
with each other, and two of the films depicted two women having
sex with each other.

Sexual Arousal
Genital arousal was assessed using a penile mercury-in-rubber
gauge measuring circumference changes during erection (Janssen,
2002). Participants indicated subjective arousal by moving
a lever forward to indicate increasing arousal and backward
to indicate decreasing arousal.

Data Analyses
Because not all men become sufficiently sexually aroused for
valid assessment, it is important to exclude nonresponders (Seto
et al., 2001).We excluded participants whose genital response to
any sexual stimuli was less than a 2-mm increase in penile circumference
and whose subjective response was less than 5%,
compared with response to neutral stimuli. The final sample
contained 21 heterosexual, 22 bisexual, and 25 homosexual men
with sufficient genital arousal for analyses and 24 heterosexual,
24 bisexual, and 31 homosexual men with sufficient subjective
arousal.
For each combination of participant and filmclip, we computed
meangenital andsubjective arousal.Next, for eachparticipant,we
standardized genital and subjective arousal across film clips. Finally,
we averaged the standardized genital arousal across female
sexual stimuli in order to compute mean genital arousal to female
stimuli; analogous calculations yielded mean genital arousal to
male sexual stimuli and to the neutral stimulus, and mean subjective
arousal to female and to male sexual stimuli, and to the
neutral stimulus. Whenever arousal to sexual stimuli was used in
analyses, we first subtracted arousal to the neutral stimulus.

RESULTS
Our first analyses examined whether men who report bisexual
feelings have a bisexual arousal pattern. Men with strong bi
bisexual
arousal need not have precisely the same degree of arousal
to both male and female stimuli. However, on average, their
arousal to both male and female stimuli should be substantial.
Furthermore, their arousal to male stimuli should exceed that
of heterosexual men, and their arousal to female stimuli
should exceed that of homosexual men. The hypothesis that
bisexual men have bisexual arousal patterns thus implies
a negative quadratic relation between self-reported sexualattraction
score (Kinsey score) and sexual arousal to the less
arousing sex (Fig. 1a).
Figure 1b shows that the predicted curvilinear relation did not
occur for genital arousal. The quadratic model was nonsignificant,
p5.68, b5
.05, DR25.00. In contrast, bisexual men’s
subjective arousal did show the predicted curvilinearity; the
negative quadratic relation was significant, p<.0001, b5
.56,
DR25.29 (Fig. 1c). Thus, we found no indication of a distinctly
bisexual pattern of genital sexual arousal among bisexual men,
although they did report a distinctly bisexual pattern of subjective
sexual arousal.
Notably, on average all men, regardless of their sexual orientation,
showed significantly more genital arousal to their less
arousing sex than they did to neutral stimuli; the 95% confidence
interval for the curve in Figure 1b is above zero. However, the
figure also shows that arousal to the less arousing sex was markedly
lower than arousal to the more arousing sex.
Our next analyses examined whether bisexual men tend to
have homosexual arousal patterns, with greater arousal to male
than to female stimuli. We computed a male-female contrast by
subtracting each participant’s arousal to female stimuli from
his arousal to male stimuli; thus, higher scores indicate more
arousal to men. If most bisexual men are primarily aroused by
male stimuli, then there should be a negative quadratic relation
between the participants’ Kinsey scores and their arousal
difference scores (Fig. 2a).

With respect to genital arousal, the quadratic relation was
significant (Fig. 2b)1; bisexual men were more aroused by male
stimuli than by female stimuli, p<.01,b5
.21,DR25.04. The
analogous quadratic relation for subjective arousal was also
significant (Fig. 2c), p<.01, b5
.16,DR25.02; bisexual men
reported greater arousal to male than female stimuli.
Although these analyses suggest that bisexual men tend to
show more arousal to male than to female sexual stimuli, inspection
of Figure 2b suggests that not all do. Several men with
Kinsey Attraction scores in the bisexual range tended to show
most genital arousal to female sexual stimuli (i.e., their arousal
contrast scores were negative). To investigate the hypothesis that
bisexual men include a mixture of men with either homosexual or
heterosexual arousal patterns, we computed the absolute residuals
from the regressions shown in Figure 2. If this hypothesis is
correct, then the residuals should be largest within the bisexual
range of the Kinsey scale, and the relation between these residuals
and Kinsey scores should be negative quadratic (Fig. 3a).
This quadratic relation was significant for both genital arousal
(Fig. 3b), p < .05, b5
.25, DR25.04, and subjective arousal
(Fig. 3c), p < .01, b 5
.33, DR2 5 .10. These results suggest
that the bisexual men whose arousal patterns were least similar to
those of homosexual men tended to have arousal patterns similar
to those of heterosexual men.

DISCUSSION

Men who reported bisexual feelings did not show any evidence of a
distinctively bisexual pattern of genital arousal. One must be
cautious, of course, in drawing conclusions from negative results.
However, the crucial analysis of arousal to the less arousing sex
did not provide even a hint of the expected effect. On average,
to one sex than to the other, and this was equally true of bisexual
men.
To be sure, most men were more genitally aroused to stimuli
depicting their less arousing sex than to neutral stimuli. This
finding contradicts some prior research in which men’s arousal
to their less preferred sex was comparable to their response to
a neutral stimulus (Freund, 1974; Freund, Langevin, Cibiri, &
Zajac, 1973). This suggests that most men may possess a certain
capacity for bisexual arousal, although the magnitude of this
arousal is quite modest.
In contrast to bisexual men’s genital arousal, their subjective
arousal did show the expected pattern. The divergence between
results for genital and subjective arousal is intriguing,
because measures of genital and subjective arousal tend to be
highly correlated in men (Sakheim et al., 1985). For example,
across all our participants, the correlation between the genital
and subjective male-female contrasts was .85. These results
suggest that with respect to their less preferred sex, either bisexual
men’s subjective arousal has been exaggerated or their
genital arousal has been suppressed. An earlier study suggests
that the former explanation is more likely. In this study, bisexual
men, compared with heterosexual and homosexual men, had
greater discrepancies between their objectively measured and
subjectively estimated genital arousal, and this was primarily
due to an overestimation of their erections to female stimuli
(Tollison et al., 1979). This issue may be clarified by studies using
emerging technology identifying brain activation patterns associated
with sexual arousal (Barch et al., 2003; Hamann, Herman,
Nolan, & Wallen, 2004). In principle, such activation
patterns could have higher validity than penile erection or selfreported
arousal as a measure of sexual arousal. In any case, our
results suggest that male bisexuality is not simply the sum of, or
the intermediate between, heterosexual and homosexual orientation.
Indeed, with respect to sexual arousal and attraction, it
remains to be shown that male bisexuality exists. Thus, future
research should also explore nonsexual reasons why some men
might prefer a bisexual identity to a homosexual or heterosexual
identity.

REFERENCES
Bailey, J.M., Dunne, M.P., & Martin, N.G. (2000). Genetic and environmental
influences on sexual orientation and its correlates in an
Australian twin sample. Journal of Personality and Social Psychology,
78, 524–536.
Barch, B.E., Reber, P.J., Levitt, M.R., Gitelman, D.R., Parrish, T.B.,
Mesulam, M.,&Bailey, J.M. (2003, November). Neural correlates of
sexual arousal in heterosexual and homosexual men. Paper presented
at the annual meeting of the Society for Neuroscience, New
Orleans, LA.
Bell, A.P., Weinberg, M.S., & Hammersmith, S.K. (1981). Sexual preference,
its development in men and women. Bloomington: Indiana
University Press.
Blanchard, R., Klassen, P., Dickey, R., Kuban, M.E., & Blak, T. (2001).
Sensitivity and specificity of the phallometric test for pedophilia in
nonadmitting sex offenders. Psychological Assessment, 13, 118–
126.
Chivers, M.L., Rieger, G., Latty, E., & Bailey, J.M. (2004). A sex difference
in the specificity of sexual arousal. Psychological Science,
15, 736–744.
Diamond, M. (1993). Homosexuality and bisexuality in different populations.
Archives of Sexual Behavior, 22, 291–310.
Fox, R.C. (2000). Bisexuality in perspective: A review of theory and
research. In B. Greene & G.L. Croom (Eds.), Education, research,
and practice in lesbian, gay, bisexual, and transgendered psychology:
A resource manual (pp. 161–206). Thousand Oaks, CA: Sage
Publications.
Freund, K. (1963). A laboratory method for diagnosing predominance
of homo- or hetero-erotic interest in the male. Behaviour Research
and Therapy, 1, 85–93.
Freund, K., Langevin, R., Cibiri, S., & Zajac, Y. (1973). Heterosexual
aversion in homosexual males. British Journal of Psychiatry, 122,
163–169.
Freund, K., Watson, R., & Rienzo, D. (1989). Heterosexuality, homosexuality,
and erotic age preference. Journal of Sex Research, 26,
107–117.
Freund, K.W. (1974). Male homosexuality: An analysis of the pattern.
In J.A. Loraine (Ed.), Understanding homosexuality: Its
biological and psychological bases (pp. 25–81). New York:
Elsevier.
Gagnon, J.H., Greenblat, C.S., & Kimmel, M. (1999). Bisexuality: A
sociological perspective. In E.J. Haeberle & R. Gindorf (Eds.),
Bisexualities: The ideology and practice of sexual contact with both
men and women (pp. 81–106). New York: Continuum.
Hamann, S., Herman, R.A., Nolan, C.L., &Wallen, K. (2004). Men and
women differ in amygdala response to visual sexual stimuli.
Nature Neuroscience, 7, 411–416.
Hirschfeld, M. (2001). Die Homosexualita¨t des Mannes und des Weibes.
Berlin: Walter de Gruyter. (Original work published 1914)
Janssen, E. (2002). Psychophysiological measurement of sexual
arousal. In M.W. Wiederman & B.E. Whitley, Jr. (Eds.), Handbook
for conducting research on human sexuality (pp. 139–171).
Mahwah, NJ: Erlbaum.
Kinsey, A.C., Pomeroy, W.B., & Martin, C.E. (1948). Sexual behavior
in the human male. Philadelphia: Saunders.
Kirkham, G.L. (2000). Homosexuality in prison. In P.C.R. Rust
(Ed.), Bisexuality in the United States (pp. 250–267). New York:
Columbia University Press.
Krafft-Ebing, R.V. (1886). Psychopathia sexualis. Stuttgart, Germany:
Enke.
Laumann, E.O., Gagnon, J.H., Michael, R.T.,&Michaels, S. (1994). The
social organization of sexuality: Sexual practices in the United
States. Chicago: University of Chicago Press.
Lever, J. (1994, August 23). Sexual revelations: The 1994 Advocate
survey of sexuality and relationships: The men. The Advocate, pp.
18–24.
MacDonald, A.P., Jr. (2000). A little bit of lavender goes a long way: A
critique of research on sexual orientation. In P.C.R. Rust (Ed.),
Bisexuality in the United States (pp. 24–30). New York: Columbia
University Press.
McConaghy, N.,&Blaszczynski, A. (1991). Initial stages of validation by
penile volume assessment that sexual orientation is distributed
dimensionally. Comprehensive Psychiatry, 32, 52–58.
Sakheim, D.K., Barlow, D.H., Beck, J.G., & Abrahamson, D.J. (1985).
A comparison of male heterosexual and male homosexual patterns
of sexual arousal. Journal of Sex Research, 21, 183–198.
Sell, R.L. (1997). Defining and measuring sexual orientation: A review.
Archives of Sexual Behavior, 26, 643–658.
Seto, M.C., Adkerson, D.L., Hindman, J., Jensen, S.H., Peters, J.M., &
Peterson, K.D. (2001). Practice standards and guidelines for
members of the Association for the Treatment of Sexual Abusers (3rd
ed.). Beaverton, OR: Association for the Treatment of Sexual
Abusers.
Stokes, J.P., Damon, W., & McKirnan, D.J. (1997). Predictors of movement
toward homosexuality: A longitudinal study of bisexual men.
Journal of Sex Research, 34, 304–312.
Tollison, C.D., Adams, H.E., & Tollison, J.W. (1979). Cognitive and
physiological indices of sexual arousal in homosexual, bisexual,
and heterosexual males. Journal of Behavioral Assessment, 1, 305–
314.
Zinik, G. (2000). Identity conflict or adaptive flexibility? Bisexuality
reconsidered. In P.C.R. Rust (Ed.), Bisexuality in the United States
(pp. 55–60). New York: Columbia University Press.
both homosexual and heterosexual men had much higher arousal

haha. sounds fun.