Digit Ratio
Digit Ratio (2D:4D)
Free
1.0.2for iPhone, iPod touch
Age Rating
Digit Ratio Screenshots
About Digit Ratio
A now widely studied putative marker for prenatal sex hormones exposure or, more precisely, for the relative exposure to testosterone compared to estrogens while in uterus, is the second-to-fourth digit ratio (2D:4D), that is the ratio between the index (2D) and the ring (4D) fingers.
Digit-ratio app is a tool to obtain anonymous measurements of digit ratios (2D:4D).
Earlier studies that have stood the test of replication have reported that 2D:4D varies by sex and ethnicity but that male 2D:4D tends to be lower than female 2D:4D in all ethnic groups and the effect is strongest in the right hand. These differences emerge prenatally and appear to be stable during the developing years.
While a number of failed replications have been reported, 2D:4D appears to be successfully associated with cognitive abilities, impulsivity, aggression and risk-taking, among other effects on personality and cognition.
The objective of the research project is to collect anonymous measurements from multiple individuals. The measurements and profile data may be sent to a server for research purposes. No image will be sent.
Digit-ratio app is a tool to obtain anonymous measurements of digit ratios (2D:4D).
Earlier studies that have stood the test of replication have reported that 2D:4D varies by sex and ethnicity but that male 2D:4D tends to be lower than female 2D:4D in all ethnic groups and the effect is strongest in the right hand. These differences emerge prenatally and appear to be stable during the developing years.
While a number of failed replications have been reported, 2D:4D appears to be successfully associated with cognitive abilities, impulsivity, aggression and risk-taking, among other effects on personality and cognition.
The objective of the research project is to collect anonymous measurements from multiple individuals. The measurements and profile data may be sent to a server for research purposes. No image will be sent.
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What's New in the Latest Version 1.0.2
Last updated on Dec 14, 2017
Old Versions
This app has been updated by Apple to display the Apple Watch app icon.
Updated detection algorithm and CSV export format.
Updated detection algorithm and CSV export format.
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Version History
1.0.2
Dec 14, 2017
This app has been updated by Apple to display the Apple Watch app icon.
Updated detection algorithm and CSV export format.
Updated detection algorithm and CSV export format.
1.0.1
Dec 10, 2017
Small improvements and changes in data export.
1.0
Nov 29, 2017
Digit Ratio FAQ
Click here to learn how to download Digit Ratio in restricted country or region.
Check the following list to see the minimum requirements of Digit Ratio.
iPhone
Requires iOS 9.0 or later.
iPod touch
Requires iOS 9.0 or later.
Digit Ratio supports English, Spanish