While most other mammals are either monogamous or polygamous, humans do not fall so neatly into these rigidly defined categories. New research suggests that where mating strategies are concerned, a man may have a natural inclination from birth towards promiscuity or faithfulness.
The name of the recent study that concluded a positive relationship toward promiscuity through a larger ring finger length is “Stay or stray? Evidence for alternative mating strategy phenotypes in both men and women.” The researchers at The University of Oxford used roughly 2,000 participants (male and female) taken from a British and North American population with an age range of 18-63.
When a child is developing in the womb, its exposure to testosterone will effect the length of the ring finger. Researchers studying mating strategies have found that an increased testosterone boost at this stage comes with an increased likelihood toward promiscuity.
The study included a questionnaire of mating habits among some participants, as well as data taken about the length of the ring finger. The measure between the index finger and ring finger is referred to as the “2D:4D” ratio.
The cad: Will have more sexual partners, therefore increasing his chances of offspring. The dad: Will stick around with the same woman, making sure his kid survive. This would be a possible Darwinian explanation of the two types.
The combined results of the online questionnaire and the ring finger data supports that there are two types of mating strategies among men: one type is more inclined toward promiscuity (57%), the other group of men are more likely to be faithful (43%).
Just looking at the ring finger length is not really enough, however. Robin Dunbar, a professor at Oxford involved with this project remarked: “Human behaviour is influenced by many factors, such as the environment and life experience… What happens in the womb might have only have a very minor effect on something as complex as sexual relationships.”