The study, published in the journal Personality and Individual Differences, explored how the ratio between the length of the index finger and the ring finger could reveal such personality traits.
For 20 days, 155 participants were asked to document any social interaction that lasted five minutes or more, checking off a list of behaviours they engaged in.
The results were pretty fascinating. Men with a smaller digit ratio, i.e. an index finger comparatively short to their ring finger, were more likely to listen attentively, smile, compliment the other person and were also far less quarrelsome with women.
“Our research suggests they have more harmonious relationships with women; these behaviors support the formation and maintenance of relationships with women,” says Debbie Moskowitz, Professor of Psychology at McGill. “This might explain why they have more children on average.”
Determination of this digit ratio has previously been pinned on the amount of testosterone that these men are exposed to in their mother’s womb. Generally, the higher the hormone levels, the smaller the ratio.
So it seems that a male’s prenatal environment can affect how they behave towards women later in life.
“It is fascinating to see that moderate variations of hormones before birth can actually influence adult behaviour in a selective way,” says Simon Young, Professor in Psychiatry and coauthor of the study.
Researchers are now looking to explore what other personality traits could be linked to this. Dominance? Competitiveness? We may soon find out.