This talk, given at the annual meeting of the International Academy of Sex Research in Chicago in August 2014 reviews the existent literature on the 'mostly heterosexuals,' those who are not exclusively heterosexual yet not same-sex oriented enough to consider themselves or be considered by others as bisexual. Reviewing over 70 studies from 6 different countries, we find that the mostly heterosexuals is a largely unrecognized, but sizable and psychologically vulnerable sexual minority.

3.  Theoretically, a continuum across various
SO indicators (attraction, arousal, fantasy,
behavior, identity)
 Practically, 3 groups: Hetero, Bi, &
Gay/Lesbian
 Until recently, MHs either not assessed or not
analyzed separately;
› Treated as heterosexual (most common)
› Treated as bisexual
› Treated as nonheterosexual
 Recently, more research on MHs as a
separate group

4.  Do MHs exist as a unique sexual
orientation group distinct from exclusive
Hs and substantial Bs?
 Is treating MHs as a separate SO group in
research (and beyond) practically useful
over combining them with heterosexuals
or bisexuals?

5. Paper 1 (Savin-Williams & Vrangalova, 2013, Dev Rev)
1. Population prevalence
2. Sexual orientation profile
3. Temporal stability
4. Subjective relevance
Paper 2 (Vrangalova & Savin-Williams, in prep)
5. Psychological and health profile

6.  Review of studies up to June 2012
 Incorporating at least one of the
psychological indicators
 60 studies, published 1994 – 2012
 30 samples (majority population-based)
 6 Western countries: US, Canada, UK,
Norway, Australia, & New Zealand
Savin-Williams & Vrangalova, 2013, Developmental Review

7. Meta-analysis of proportions
General population (21 samples, 6
countries):
 Women: 8.6%; Range 1.2% - 15.4%
 Men: 3.9%; Range 1.4% - 5.6%
College samples (5 samples, US):
 Women: 15.6%; Range 7.7 – 22.6%
 Men: 6.9%; Range 2.8 – 8.3%

8.  MH - single largest nonheterosexual group;
 Often (70% m; 90% f samples) MH larger
than all other nonheterosexuals (B, MGL,
GL) combined
 Women 1.2-4.7 (median = 2.4) times more
likely to report being MH
 Cohort effects: among women
 Developmental effects:
› Women: Increase through mid-/late-20s, then
decrease
› Men: Increase through early 20s, then stable

9.  Same-sex attraction/fantasy, partners,
and arousal (men only): H < MH < B
 Other-sex sexuality
› Attraction and arousal (men): H = MH > B
› Partners
 Women: H ≥ MH > B
 Men: H ≤ MH > B

10. 3 longitudinal studies; 2 samples
 MH identity was stable for ~50% over any
two time points from early adolescence
through adulthood; for ~25% across 3+
time points
› Such stability lower than H, but higher than B
 Of those who moved toward or away
from MH, vast majority migrated to or
emigrated from H

11.  Qualitative studies – MH highly desirable
label & legitimate descriptor
 Greater identity uncertainty and
exploration than H, but clear
commitment in many/most
 When not given MH option; vast majority
(80%-93%) identifies as H

12.  70 studies, 1991-2013
 32 samples (most population-based)
 MH vs. H and MH vs. B
 Meta-analysis - Unweighted Cohen d’s
› d >= 0.80 - large,
› 0.80 > d > 0.20 - medium,
› d <= 0.20 small,
› d < 0.10 negligible
 Higher d’s mean MHs possess trait more
(Vrangalova & Savin-Williams, in prep)

13. Men Women
k M Range k M Range
Internalizing (mood,
suicidality, anxiety)
11 0.40 -0.04 – 0.66 14 0.32 0.05 – 0.46
Disordered eating 3 0.69 0.34 – 1.15 4 0.30 0.18 – 0.39
Body image problems 3 0.23 0.19 – 0.36 4 0.11 -0.05 – 0.23
Sexual health (STIs, teen
pregnant, abnormal
Pap)
2 0.45 0.44 – 0.46 6 0.37 0.18 – 0.61
Physical health (general
health, overweight,
specific conditions)
2 0.11 0.01 – 0.22 3 0.17 0.11 – 0.22
k - # samples
M – mean effect size across all samples;

14. Men Women
k M Range k M Range
Substance use (smoking,
alcohol, drugs)
9 0.29 -0.02 – 0.66 11 0.45 0.26 – 0.63
Sexual risk taking (early
onset, multiple partners,
condom non-use)
7 0.13 -0.20 – 0.75 11 0.40 -0.08 – 0.77
Other risk taking
(gambling, aggression,
delinquency)
3 0.10 0.07 – 0.13 3 0.18 0.07 – 0.37
Preventive health
behaviors (regular
checkups, Pap testing)
0 - - 3 -0.09 -0.14 – -0.03
k - # samples
M – mean effect size across all samples;

15. Men Women
k M Range k M Range
Victimization
(sexual, nonsexual)
8 0.29 -0.04 – 0.51 11 0.32 -0.05 – 0.85
Stressful/Risky
environment
3 0.21 0.17 – 0.23 6 0.34 0.12 – 0.50
Personal & social
relationships,
connectedness
4 -0.31 -0.49 – -0.19 7 -0.38 -0.53 – -0.28
Gender
nonconformity
4 0.57 0.35 – 0.79 2 0.51 0.40 – 0.60
SES (education,
income)
4 0.22 -0.02 – 0.66 7 0.13 -0.03 – 0.69
k - # samples
M – mean effect size across all samples

16. Men Women
k M Range k M Range
Internalizing (mood,
suicidality, anxiety)
8 -0.22 -0.59 – -0.02 11 -0.27 -1.29 – 0.38
Disordered eating 2 -0.45 -0.60 – 0.31 3 -0.22 -0.28 – -0.17
Body image problems 1 0.13 1 -0.12
Sexual health (STIs,
teen pregnant,
abnormal Pap)
2 -0.31 -0.60 – -0.02 5 -0.04 -0.30 – 0.12
Physical health
(general health,
overweight, specific
conditions)
2 -0.11 -0.18 – -0.05 3 -0.14 -0.19 – -0.11
k - # samples
M – mean effect size across all samples;

17. Men Women
k M Range k M Range
Substance use (smoking,
alcohol, drugs)
6 -0.05 -0.36 – 0.33 8 -0.13 -0.40 – -0.22
Sexual risk taking (early
onset, multiple partners,
condom non-use)
5 -0.56 -0.75 – -0.03 8 -0.25 -0.72 – 0.15
Other risk taking
(gambling, aggression,
delinquency)
3 -0.22 -0.35 – -0.00 3 -0.22 -0.35 – -0.00
Preventive health
behaviors (regular
checkups, Pap testing)
0 - - 3 0.21 0.01 – 0.49
k - # samples
M – mean effect size across all samples;

18. Men Women
k M Range k M Range
Victimization
(sexual, nonsexual)
8 -0.39 -0.65 – -0.06 10 -0.26 -0.88 – 0.10
Stressful/Risky
environment
2 -0.05 -0.15 – 0.05 4 -0.11 -0.46 – 0.12
Personal & social
relationships,
connectedness
4 0.28 -0.12 – 0.86 6 0.03 -0.32 – 0.21
Gender
nonconformity
2 -0.62 -0.91 – -0.33 2 -0.44 -0.75 – -0.13
SES (education,
income)
3 0.35 0.27 – 0.39 5 0.32 0.21 – 0.44
k - # samples
M – mean effect size across all samples

19.  MHs are a numerous SO group unique in
their sexual orientation profile
 Similar to other nonheterosexuals, MHs
have elevated health vulnerabilities
compared to H, but somewhat less than
B
 Need to start treating them as a
separate group in research and practice