Selfless behavior could have evolved because it was a very important quality, highly appreciated by our ancestors, when they were looking for a mate.
This is the conclusion of a new research carried out by Dr Tim Phillips and colleagues from the University of Nottingham and Institute of Psychiatry, King's College, London.
Their study analyzed whether this evolution of the selfless behavior was a result of partner selection criteria, and they concluded that there is also genetic evidence to this.
The researchers had 70 identical and 87 non-identical female twin pairs, filling out questionnaires related to their own levels of altruism – like whether or not they gave money to charity, and how attractive they found this in potential mates – dive into a river to save a “damsel in distress”.
Their responses were introduced into a statistical model, which analyzed them and revealed that genes had a major influence on variation of the subjects' preferences for a certain mate and their own selfless behavior.
This led scientists to conclude that it is a way of choosing a sexual partner, and that this might be genetic, AlphaGalileo reports.
Also, considering this idea, we could say that in the past, people with a stronger mate preference towards an altruistic behavior, mated more often with selfless partners.
Dr Phillips explained that the “results are consistent with a link between human altruism towards non-relatives and sexual selection and throws an exciting new light on the puzzle of altruistic behavior - which appears, at first sight, to be at odds with evolutionary theory."
"The expansion of the human brain would have greatly increased the cost of raising children so it would have been important for our ancestors to choose mates both willing and able to be good, long-term parents.
“Displays of altruism could well have provided accurate clues to this and so led to a link between human altruism and sexual selection.”
This finding was published in the British Journal of Psychology.