The difference in size of a person’s index and ring fingers could correlate with that’s person’s aggressive disposition, according to a new UB study.

Led by UB assistant professor of communication Allison Z. Shaw, researchers found that verbal aggression (“name calling, ridicule, insults, racial epithets and threats”) is connected to biological factors, which can be measured by comparing a person’s fingers. The ratio of length of a person’s ring finger (2D) to the length of the index finger (4D), the study explains, is indicative of a fetus’ exposure to testosterone.

The study, published in the Journal of Communication, supports previously found evidence of testosterone exposure being related to the 2D:4D ratio. The research conducted by Shaw and her team determined that such levels of testosterone exposure correlated with verbal aggression patterns in test subjects.

The smaller the 2D:4D ratio, the more verbally aggressive the test subject, Shaw’s team discovered.

“They suggest,” Shaw said in a UB news release, “that verbally aggressive behavior may be provoked by biologically based differences in people’s attention to potentially threatening stimuli (such as a sigh), their appraisal of the stimuli as threatening and the resulting decision to respond and produce messages that are verbally aggressive.”