ORIGINAL PAPER
Eye-Tracking of Men’s Preferences for Waist-to-Hip Ratio
and Breast Size of Women
Barnaby J. Dixson Æ Gina M. Grimshaw Æ
Wayne L. Linklater Æ Alan F. Dixson
Received: 2 February 2009 / Revised: 14 April 2009 / Accepted: 29 April 2009 / Published online: 18 August 2009
 Springer Science+Business Media, LLC 2009
Abstract Studies of human physical traits and mate pref-
erences often use questionnaires asking participants to rate the
attractiveness of images. Female waist-to-hip ratio (WHR),
breast size, and facial appearance have all been implicated in
assessments by men of female attractiveness. However, very
little is known about how men make fine-grained visual
assessments of such images. We used eye-tracking techniques
to measure the numbers of visual fixations, dwell times, and
initial fixations made by men who viewed front-posed pho-
tographs of the same woman, computer-morphed so as to
differ in her WHR (0.7 or 0.9) and breast size (small, medium,
or large). Men also rated these images for attractiveness. Re-
sults showed that the initial visual fixation (occurring within
200 ms from the start of each 5 s test) involved either the
breasts or the waist. Both these body areas received more first
fixations than the face or the lower body (pubic area and legs).
Men looked more often and for longer at the breasts, irre-
spective of the WHR of the images. However, men rated
images with an hourglass shape and a slim waist (0.7 WHR) as
most attractive, irrespective of breast size. These results pro-
vide quantitative data on eye movements that occur during
male judgments of the attractiveness of female images, and
indicate that assessments of the female hourglass figure
probably occur very rapidly.
Keywords Sexual attractiveness  Evolution 
Female waist-to-hip ratio  Female breast size  Eye-tracking
Introduction
The nature of physical attractiveness has fascinated scholars for
centuries. Indeed, attractiveness has often been shrouded in
mystery. However, people across cultures state that physical
attractiveness is an important trait in a potential partner (Buss,
1989). Evolutionary psychologists have suggested that selec-
tion has shaped human cognitive mechanisms to recognize
physical traits that signal health and fertility (Grammer, Fink,
Møller, & Thornhill, 2003). The attractiveness of such traits
may therefore represent the results of sexual selection operating
within ancestral human populations (Buss, 2003; Miller, 2000).
Men and women are strikingly sexually dimorphic in
muscularity and body fat. Women have almost twice the
amount of body fat of men (Clarys, Martin, & Drinkwater,
1984). The distribution of body fat is a secondary sexual
characteristic in women. Body fat is laiddown during pubertal
development on the hips, buttocks, thighs (the gluteofemoral
region), and breasts. Body fat distribution is important for
triggering menarche in girls (Lassek & Gaulin, 2007) and
maintaining regular ovulatory cycles (Singh, 2002). The dis-
tribution of women’s body fat can be measured using the
waist-to-hip ratio (WHR), which computes the ratio between
body circumference at the waist and the hips (Singh, 1993).
Women with lower WHRs have a body fat distribution con-
sistent with greater health and reproductive potential (Singh,
2002, 2006) and, at the physiological level, it has been shown
that larger breasts and slim waists are associated with higher
estrogen and progesterone levels (Jasienska, Ziomkiewicz,
Ellison, Lipson, & Thune, 2004), which are predictors of the
probability of conception (Lipson & Ellison, 1996). Images of
women with low WHRs (in the range 0.6–0.8) are more
attractive to men from Cameroon (Dixson, Dixson, Morgan,
& Anderson, 2007), Germany (Henss, 2000), China (Dixson,
Dixson, Li, & Anderson, 2007), the UK (Furnham, Tan, &
B. J. Dixson (&)  W. L. Linklater  A. F. Dixson
School of Biological Sciences, Victoria University of Wellington,
Wellington, New Zealand
e-mail: Barnaby.Dixson@vuw.ac.nz
G. M. Grimshaw
School of Psychology, Victoria University of Wellington,
Wellington, New Zealand
123
Arch Sex Behav (2011) 40:43–50
DOI 10.1007/s10508-009-9523-5

McManus, 1997), the U.S., and New Zealand (Dixson, Dix-
son, Bishop, & Parrish, 2008).
The evolutionary significance of prominent breasts in
women has been much debated. Some authors have ascribed
a functional role to large breasts. For example, as humans
evolved hairlessness and bipedal locomotion, larger pendu-
lous breasts were adaptive for breast-feeding babies (Le-
Blanc & Barnes, 1974) and provided a soft cushion that is
psychologically comforting to the infant (Smith, 1986). Dur-
ing times of nutritional scarcity, breasts may act as milk
storage organs (Low, Alexander, & Noonan, 1987) and fat
reserves for breast-feeding babies (Anderson, 1983). How-
ever, many of these arguments have since been refuted. There
is no relationship between larger breasts prior to pregnancy
and improved lactation, as women with smaller breasts are
able to feed their babies as effectively (Anderson, 1988; Pond,
1998). Breast enlargement may occur as a by-product of
gluteofemoral fat deposition (Pawlowski, 1999) and theories
ascribing a functional role to permanently enlarged breasts
remain debatable. However, sexual selection via male partner
choice may also explain the evolution of prominent breasts
in women as a cue to adult sexual maturity (Gallup, 1982;
Marlowe, 1998). Studies of male preferences for female
breast size have produced mixed results. Some studies have
found that men rate line drawings of women with medium
sized breasts as most attractive (Horvath, 1981; Wiggins,
Wiggins, & Conger, 1968) while other studies have found that
men prefer smaller breasts (Furnham, Swami, & Shah, 2006)
or largerbreasts (Singh& Young,1995).Themixed responses
from men reported in these studies suggest that further
investigations of female breast size and sexual attractiveness
would be valuable.
How do men analyze female morphological traits, such as
WHR and breast size, when reaching decisions about the
overall attractiveness of the female face and body? Eye-
tracking provides a more objective measurement of the focus
of attention during judgments of attractiveness than ques-
tionnaire-based studies. Attractiveness, particularly in wo-
men, comprises a set of physical traits that captures the
attention of the opposite sex (Maner, Gailliot, & DeWall,
2007). Eye-tracking research has shown that participants of
both sexes look preferentially at faces of attractive women
(Fink et al., 2008; Maner, DeWall, & Gailliot, 2008). How-
ever, there is currently only limited information on how men
process female WHR when making attractiveness judgments.
Suschinsky, Elias, and Krupp (2007) conducted eye-tracking
studies to measure men’s responses to female images varying
in WHR. The images were clothed, but a consistent finding
was that men spent more time examining the breasts, irre-
spective of variations in WHR. Eye-tracking techniques have
also been used to measure visual attention of both sexes to
images depicting erotic heterosexual interactions (Lykins,
Meana, & Kambe, 2006; Rupp & Wallen, 2007). However, in
such cases, the visual scenes are complex, making it difficult
to conduct fine-grained analyses of visual attention in relation
to specific morphological traits.
In this study, we used eye-tracking procedures to measure
how men examined images of front-posed naked women
varying inWHR and breast size. Specifically,wemeasured the
initial fixation, number of visual fixations, and the amount of
time men spent looking at defined areas of the female body and
face. Men were also asked to rate the various images for sexual
attractiveness. The purpose was to quantify eye movements
and visual attention along with judgments of female attrac-
tiveness. Several hypotheses might be advanced regarding eye
movements during judgments of female attractiveness. Men
might spend significant time examining the face, the breasts,
the waist or the pubic area given that all these areas are in-
volved in female attractiveness and reproduction. However,
the crucial issue was to obtain quantitative measures of which
areas of the body men looked at and how frequently they
examined them during eye-tracking experiments.
Method
Participants
A total of 36 men of European descent, ranging in age from 22
to 42 years (M = 27.42 years; SD = 4.99), were recruited
opportunistically from the post-graduate student body at
Victoria University. Participants were given individual verbal
orientation before the start of data collection and allowed
some time to familiarize themselves with the room and eye-
tracking machine. The details of the study were not discussed
with participants beforehand. However, when each partici-
pant had completed the experiments, they were provided with
written details of the rationale for the research. Each partici-
pant was told of their right to withdraw themselves or their
data from the study without prejudice. The project was pre-
approved by the Human Ethics Committee of the School of
Psychology at Victoria University.
Measures and Procedure
A photograph of a front-posed naked woman was scanned
from Simblet (2001). Waist-to-hip ratio (WHR) and breast
size were manipulated in this image using Photoshop Version
7.0. Three different breast sizes were created using anthro-
pometric measurements taken from Brown et al. (1999).
Images with small breasts (80% of the original image),
medium (unchanged), and large (120% of the original size)
were made. Each breast size was shown on a figure with a
waist-to-hip ratio of 0.7 or 0.9. Thus, six images were con-
structed in total. The experiment was programmed using the
SR Research Experiment Builder (version 1.4.128 RC) and
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