That’s the finding of a study by Italian economists, quoted recently in the Huffington Post. Italian economists Aldo Rustichini and Luigi Guiso asked the question, why do some women achieve success in high-tech careers and some do not? They interviewed more than 2,000 Italian male and female small-business owners and founders. During the interview, the entrepreneurs were asked to hold out their right hands, palm up, so a photograph could be taken and used to measure the length of their ring fingers relative to their index fingers.
As strange as it may sound, 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. Rustichini’s own work has connected it to real-life success, such as the profitability of London high-frequency financial traders.
After analyzing the photos, the researchers found the more successful the entrepreneur, the longer the ring finger compared to the index finger. The most successful entrepreneurs had ring fingers 10% to 20% longer than their index finger.
The researchers asked a second question of why this physical trait leads to greater success. Further research revealed that during pregnancy, the fetal ring finger has many receptors for hormones, such as testosterone and estrogen, 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.
Thus, the length of the ring finger is a marker for fundamental — but not entirely known — brain system differences. The study suggests that entrepreneurs are special, wired to be more competitive 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.
According to Rustichini, ring finger size and the way your brain is wired are only parts of a person’s eventual success in life. If people’s childhoods do not cultivate the competitive psyche, or if the society they live in is not supportive of women’s efforts, they are never going to succeed as entrepreneurs, no matter how long their ring fingers are. The rest, Rustichini will be filtered out — in ways that men are not. If entrepreneurs are special, then female entrepreneurs have to be super-special.