Digit length and Dominance:
Investigating difference in 2D:4D
ratio dominant and non-dominant
hand
Rens, M
ID: I6386308
Tutorial group: 2
Faculty of Health, Medicine and Life Sciences (FHML)
Maastricht University
1
, Course BBS1001
9 October 2024
1. Introduction
The 2D:4D ratio, the ratio between the lengths of the index finger (2D) and the
ring finger (4D), between sexes and population have been examined by many
studies. The 2D:4D ratio is thought to be a potential indicator of prenatal
androgen exposure (PAE), especially androgens and estrogens [2]. The index
finger (2D) is generally shorter than the ring finger (4D) in both males and
females. The length difference between the index finger (2D) and ring finger
(4D) is generally larger than it is in females [3]. A lot of studies are suggesting
that this ratio is associated with various biological behavioral and physiological
traits, like Asperger’ s syndrome, cognitive abilities, spatial skills, sperm counts,
depression, myopia, eating disorders and handedness [3].
There are many studies on the 2D:4D ratio and its associating with biological
behavioral and physiological traits, but a few studies have focused on the
difference in this ratio between dominant and non-dominant hands. Handedness
is the tendency to select one hand over the other for specific tasks [4]. It is
commonly assumed that the dominant hand, controlled by the dominant
hemisphere is superior in performing all upper extremity tasks. Hand dominance
is linked to motor control and brain lateralization [4]. The implications of several
studies that suggest that ratio is associated with handedness deserves to be
explored further, because this could provide new insights into the relationship
between brain development, prenatal hormonal exposure and lateralization.
This study set out to answer the following question: is the 2D:4D ratio different
between the dominant and non-dominant hand in first year Biomedical Science
students?
A sample of 200 Biomedical students from Maastricht University is used for this
research question. The 2D and 4D is measured of both hands in millimeters. The
students also need to give information about which hand is their dominant hand
2
Investigating difference in 2D:4D
ratio dominant and non-dominant
hand
Rens, M
ID: I6386308
Tutorial group: 2
Faculty of Health, Medicine and Life Sciences (FHML)
Maastricht University
1
, Course BBS1001
9 October 2024
1. Introduction
The 2D:4D ratio, the ratio between the lengths of the index finger (2D) and the
ring finger (4D), between sexes and population have been examined by many
studies. The 2D:4D ratio is thought to be a potential indicator of prenatal
androgen exposure (PAE), especially androgens and estrogens [2]. The index
finger (2D) is generally shorter than the ring finger (4D) in both males and
females. The length difference between the index finger (2D) and ring finger
(4D) is generally larger than it is in females [3]. A lot of studies are suggesting
that this ratio is associated with various biological behavioral and physiological
traits, like Asperger’ s syndrome, cognitive abilities, spatial skills, sperm counts,
depression, myopia, eating disorders and handedness [3].
There are many studies on the 2D:4D ratio and its associating with biological
behavioral and physiological traits, but a few studies have focused on the
difference in this ratio between dominant and non-dominant hands. Handedness
is the tendency to select one hand over the other for specific tasks [4]. It is
commonly assumed that the dominant hand, controlled by the dominant
hemisphere is superior in performing all upper extremity tasks. Hand dominance
is linked to motor control and brain lateralization [4]. The implications of several
studies that suggest that ratio is associated with handedness deserves to be
explored further, because this could provide new insights into the relationship
between brain development, prenatal hormonal exposure and lateralization.
This study set out to answer the following question: is the 2D:4D ratio different
between the dominant and non-dominant hand in first year Biomedical Science
students?
A sample of 200 Biomedical students from Maastricht University is used for this
research question. The 2D and 4D is measured of both hands in millimeters. The
students also need to give information about which hand is their dominant hand
2
