All Conference Presentations, Performances and Exhibits
Does Size Matter? A Closer Look at Finger Digit Ratios in Relation to Prenatal Testosterone
Location
Guzman Lecture Hall
Start Date
4-14-2016 7:00 PM
End Date
4-14-2016 8:00 PM
Student Type
Undergraduate
Faculty Mentor(s)
William Philips, Ph.D.
Presentation Format
Poster Presentation
Abstract/Description
It is common knowledge to understand that sexual orientation (homosexuality, bisexuality, etc.) is caused through a combination of complex genetic and environmental factors (Iemmola & Ciani, 2009). Research suggests that sexual orientation is linked to the presence of prenatal testosterone during specific sensitive periods of development. Although it is unethical to test this with humans, science can look towards other phenotypic characteristics to make inferences about the womb environment during prenatal development. Knowing that testosterone is also linked to bone growth, research has examined the 2nd to 4th digit finger ratios (2D:4D) as a measure for the presence of testosterone (Kraemer, Bernd, Delsignore, Milos, Schnyder, & Hepp, 2006). However, results of this research has been largely inconsistent and it has only been conducted on small homosexual samples.
The current study aims to gather information from a large, diverse population to determine whether or not digit ratio is a legitimate measure for predicting sexual orientation in adults. Volunteers will be recruited from San Francisco’s Mission and Castro districts, as well as students from Dominican University of California. Participants will answer demographic questions regarding age, sex, gender identity, race, sexual orientation, and their birth order relative to siblings. After completing the survey, participants will be asked to place their hand on standard 8.5” x 11” Cartesian graph sheet where their dominant hand will be photographed for future measurement. It is hypothesized that 2D:4D ratio is related to sexual orientation (e.g. the digit ratio of lesbian women is more similar to the digit ratio of heterosexual men). This study also aims to observe birth order as a significant factor for sexual orientation, known as the Fraternal Birth Order Effect (FBOE: Currin, Gibson & Hubach, 2015). The second hypothesis is that males will have an increased likelihood of non-heterosexuality with increasing numbers of male siblings born before them. Data collection for this study will take place in February and March of 2016.
Does Size Matter? A Closer Look at Finger Digit Ratios in Relation to Prenatal Testosterone
Guzman Lecture Hall
It is common knowledge to understand that sexual orientation (homosexuality, bisexuality, etc.) is caused through a combination of complex genetic and environmental factors (Iemmola & Ciani, 2009). Research suggests that sexual orientation is linked to the presence of prenatal testosterone during specific sensitive periods of development. Although it is unethical to test this with humans, science can look towards other phenotypic characteristics to make inferences about the womb environment during prenatal development. Knowing that testosterone is also linked to bone growth, research has examined the 2nd to 4th digit finger ratios (2D:4D) as a measure for the presence of testosterone (Kraemer, Bernd, Delsignore, Milos, Schnyder, & Hepp, 2006). However, results of this research has been largely inconsistent and it has only been conducted on small homosexual samples.
The current study aims to gather information from a large, diverse population to determine whether or not digit ratio is a legitimate measure for predicting sexual orientation in adults. Volunteers will be recruited from San Francisco’s Mission and Castro districts, as well as students from Dominican University of California. Participants will answer demographic questions regarding age, sex, gender identity, race, sexual orientation, and their birth order relative to siblings. After completing the survey, participants will be asked to place their hand on standard 8.5” x 11” Cartesian graph sheet where their dominant hand will be photographed for future measurement. It is hypothesized that 2D:4D ratio is related to sexual orientation (e.g. the digit ratio of lesbian women is more similar to the digit ratio of heterosexual men). This study also aims to observe birth order as a significant factor for sexual orientation, known as the Fraternal Birth Order Effect (FBOE: Currin, Gibson & Hubach, 2015). The second hypothesis is that males will have an increased likelihood of non-heterosexuality with increasing numbers of male siblings born before them. Data collection for this study will take place in February and March of 2016.