Economists Aldo Rustichini and Luigi Guiso hired a small army of 200 assistants to go out and interview over two thousand Italian men and women small-business owners and founders.
While taking interviews, the scholars also captured images the entrepreneurs' right hand palms to measure the length of their ring fingers relative to their index fingers, according to the Huffington Post.
Surprisingly they found that the ratio of index to ring finger correlates with traits such as spatial ability, risk-taking, and assertiveness. It's connected to success in competitive sports like soccer and skiing.
More interestingly, their analysis of the photos found that the more successful the entrepreneur, the longer the ring finger compared to the index finger. The most successful entrepreneurs had ring fingers 10 per cent to 20 per cent longer than their index finge.
This finding probably sounds downright absurd. But it's not really about the length of your fingers. Finger length is actually just a marker of what was going on in your mother's womb.
A couple months into gestation, fingers sprout and elongate, and, also during that time, the early limbic brain gets organized. Both of these are affected by the prevalence of the hormones testosterone and estrogen, which come both from the fetus's own sex glands and the mother's bloodstream.
The fetal ring finger has many receptors for both hormones on it, and the index finger has fewer receptors. Testosterone lengthens the fetal fingers, while estrogen stops their growth, and thus the balance of the two hormones can affect the ring finger and index finger differently. The two hormones simultaneously shape the development of the brain.
All of which is a very technical way to explain that the length of the ring finger is a marker for fundamental – but not entirely known – brain system differences.
Normally, men's ring fingers are a tad longer, and women's index fingers are a tiny bit longer. But in the Italian study, the female entrepreneurs actually had more of a male pattern: their ring fingers were longer. In fact, it was more pronounced in that direction than the men's. And it wasn't just their ring fingers that were bigger: on average, they ran bigger companies, with higher growth rates. They also had greater ability to withstand enormous workloads.
This suggests that entrepreneurs are special, wired that way from the fetal stages of development. More men might be wired this way than women, but if you are wired this way, it transcends gender.
But this does not imply that venture capital firms should just throw out the business plans and take photos of entrepreneurs' hands. It's not all biology.
Rustichini noted that some scientists believe that all the biological components of competitiveness, taken together, comprise 40 per cent of the explanation. Others argue it's more like 60 per cent.
According to Rustichini, if people's childhoods don't cultivate the competitive psyche, or if the society they live in isn't supportive of women's efforts, they're never going to succeed as entrepreneurs, no matter how long their ring fingers are.