Patrick Orr1, Heather Tropiano1,

1
Patrick Orr1, Heather Tropiano1, J. Timothy
Cannon1,21Psychology Department 2Neuroscience
Program, The University of Scranton, Scranton, PA.
665.22
Mental Rotation Perspective Taking Sex
Differences Relationships with 2D/4D Ratio
Abstract Recent efforts have distinguished
spatial orientation ability or perspective
taking as a specific spatial ability that is
separable from mental rotation (Kozhevnikov
Hegarty, 2001 Hegarty Waller, 2004). Although
there is a consistent sex difference favoring
males for mental rotation (Spelke, 2005 Linn
Petersen, 1985 Voyer, Voyer, Bryden, 1995),
sex differences for perspective taking ability
have not been reported since it was recognized as
being distinct from mental rotation. 2D4D
Finger Ratio has been identified as a marker for
prenatal androgen exposure. 2D4D Ratio
correlates negatively with androgen exposure and
is established and stable by week 14 of
gestation. 2D4D Ratio has been studied in
relation to fertility, attractiveness, sexual
preference, athletic and musical ability, verbal
fluency, and depression (Manning,
2002). Performance on the Perspective
Taking/Spatial Orientation task (Hegarty
Waller, 2004), a computer version of the
Vandenberg-Kuse Mental Rotation Task, and
measurements of right hand 2D4D Finger Ratios,
were analyzed in 121 college students (47 male).
Males had significantly higher scores on Mental
Rotation and Perspective Taking. There was a
significant positive correlation between Mental
Rotation and Perspective Taking scores across all
participants. As expected, females had
significantly higher 2D4D Finger Ratios. 2D4D
Ratio did not correlate significantly with
performance on the Mental Rotation task in either
sex, but for females only there was a significant
positive correlation between 2D4D Ratio and
performance on the Perspective Taking Task. The
abstract above is changed from the published
abstract due to an unnoticed error prior to
submission. The measure of Perspective Taking
used prior to abstract submission was a measure
of the error participants made on the task. The
corrected abstract uses a transformed version of
the error term, so that a high score means better
performance. Consequently, all correlations
involving Perspective Taking which were reported
as negative in the submitted abstract are now
positive in the presented abstract. Background
Until recently, there has been little
differentiation in the ability to measure Mental
Rotation spatial ability - the ability to
mentally rotate a perceived object - and
Perspective Taking spatial ability the
ability to mentally rotate ones own point of
view. Purported measurements of Perspective
Taking have always loaded on the same factor as
Mental Rotation. Recent efforts (Kozhevnikov
Hegarty, 2001 Hegarty Waller, 2004) have shown
these two abilities to be correlated but
separable. Although strong and stable sex
differences have been shown for Mental Rotation
ability (Spelke, 2005 Linn Petersen, 1985
Voyer, Voyer, Bryden, 1995), there has been
little data on the issue of sex differences in
the recently separated Perspective Taking
ability. The ratio of the length of the index
finger to the length of the ring finger (2D4D
Ratio) can be used as a marker of prenatal
androgen exposure. 2D4D Ratio correlates
negatively with androgen exposure and is
established and stable by week 14 of gestation.
2D4D Ratio has been studied in relation to
fertility, attractiveness, sexual preference,
athletic and musical ability, verbal fluency, and
depression (Manning, 2002). It has been
suggested that 2D4D ratio could be predictive of
performance in cognitive tasks which show sex
differences (Coolican Peters, 2003). There has
been mixed support for the usefulness of 2D4D
ratio in predicting Mental Rotation performance.
Oddly, some studies have reported that 2D4D
Ratios are positively correlated with performance
on a Mental Rotation task greater prenatal
androgen exposure correlated with lower Mental
Rotation performance (Manning, 2002). Others
have reported no correlation between 2D4D Ratio
and Mental Rotation (Coolican Peters, 2003).

• Methods
• Participants consisted of 121 students (47 Male)
  enrolled in an introductory psychology class
• Participants were tested in groups of 15-20
• Testing groups were approximately 50 male/female
• On the testing day, participants
• provided demographic information (age, major in
  school, gender, year in school, home state,
  ethnicity)
• took the Object Perspective Task (Hegarty
  Waller, 2004), a paper-and-pencil measure of
  perspective taking ability
• completed a group-administered, computer version
  of the Vandenberg-Kuse Mental Rotations Task
• had their hands digitized by a bed scanner
• Finger lengths were measured using the ImageJ
  software available from the NIH at
  http//rsb.info.nih.gov/ij/.

Discussion Based on these data, the sex
differences typically found in Mental Rotation
seem to extend to the recently recognized
Perspective Taking ability. In these data, the
correlation between Mental Rotation and
Perspective Taking for all participants seems to
be driven by variation in female participants.
The positive correlation between 2D4D Ratio
and Perspective Taking for females suggests that
those females exposed to less androgens performed
better at Perspective Taking. This is concordant
with previous findings (Manning Taylor, 2001)
indicating that 2D4D Ratios correlated
positively with Mental Rotation ability. Our
finding is also congruent with the nearly
significant positive correlation between Mental
Rotation and 2D4D Ratio for females, r .25, p
.090 (two-tailed). For males, the positive
correlation between Mental Rotation and
Perspective Taking, and the negative correlation
between 2D4D Ratio and Mental Rotation were near
significance. Further investigation with a larger
sample size is warranted, as they may yield
significant results with greater power.
References Coolican, J., Peters, M. (2003).
Sexual dimorphism in the 2D/4D ratio and its
relation to mental rotation performance.
Evolution and Human Behavior, 24,
179-183. Hegarty. M. Waller, D. (2004). A
dissociation between mental rotation and
perspective-taking spatial abilities.
Intelligence, 32, 175-191. Kozhevnikov, M.
Hegarty, M. (2001). A dissociation between object
manipulation spatial ability and spatial
orientation ability Memory Cognition, 29,
745-756. Linn, M.C. Petersen, A.C. (1985).
Emergence and characterization of sex differences
in spatial ability A meta-analysis. Child
Development, 56, 1479-1498. Manning, J.T. (2002).
Digit Ratio. New Brunswick, NJ Rutgers
University Press. Spelke, E.S. (2005).Sex
differences in intrinsic aptitude for mathematics
and science A critical review. American
Psychologist, 60, 950-958. Voyer, D., Voyer, S.,
Bryden, M.P. (1995). Magnitude of sex
differences in spatial abilities A meta-analysis
and consideration of critical variables.
Psychological Bulletin, 117, 250-270.
Special Thanks to Brentt Swetter