Alpha males portray a greater tendency of taking risks in relationships, according to a recent study from Concordia University.
The study found the length between the second and fourth finger is an indicator of high levels of prenatal testosterone, risk-taking and potential financial success in men.
"Our findings show an association between high testosterone and risk-taking among males in three domains: recreational, social and financial," said senior researcher Gad Saad.
"Since women tend to be attracted to men who are fit, assertive and rich, men are apt to take risks with sports, people and money to be attractive to potential mates. What's interesting is that this tendency is influenced by testosterone exposure - more testosterone in the womb can lead to more risks in the rink, the bar and the trading floor in later in life," said Concordia doctoral student, Eric Stenstrom.
Saad and his team analyzed risk-taking among 413 male and female students using a survey and found that prenatal testosterone exposure not only influences foetal brain development but also slows the growth of the index finger relative to the sum of the four fingers excluding the thumb.
These correlations were only observed in men.
"A possible explanation for the null effects in women is that they do not engage in risky behaviour as a mating signal, whereas men do," said Saad.
The findings are published in the journal of Personality and Individual Differences.