Nice guys actually finish first when it comes to getting the girl, new research suggests.

一项新的研究表明，好男人事实上能够最先追到女孩。

Psychologists（心理学家） believe that traits such as selflessness and altruism¹（利他主义） have become part of our genetic² make-up because they were attractive to mates.

They believe that as humans evolved, qualities such as being fittest and strongest were usurped（篡夺，夺取） by other qualities – such as offering a helping³ hand in bringing up the children.

“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," said Dr Tim Phillips and colleagues from the University of Nottingham and Institute of Psychiatry⁴（精神病学） , King’s College, London.

"Displays of altruism could well have provided accurate clues to this and so led to a link between human altruism and sexual selection.”

The study, which investigated whether altruistic⁵ behaviour evolved as a result of sexual selection, involved 70 identical and 87 non-identical female twin pairs.

They completed questionnaires relating to their own levels of altruism by answering questions such as "have you given money to charity?" and "have you dived into a river to save someone from drowning?"

They then asked them if they would find the same qualities desirable（令人满意的） in potential mates.

Statistical⁶ analysis of their responses suggested that, in our evolutionary⁷ past, those with a stronger mate preference towards altruistic behaviour mated more frequently with more altruistic people. That means that altruistic genes⁸ would be more prevalent（流行的，普遍的） than selfish genes.

Dr Phillips said: “These 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 behaviour – which appears, at first sight, to be at odds⁹ with（不和，差异） evolutionary theory.”

The results were published in the British Journal of Psychology¹⁰.