Naturalist Charles Darwin's theory that music's primary function is sexual courtship may have been proved right, according to new research.
His argument has been supported by a study from the University of Sussex which shows that during the most fertile phase of their menstrual cycle, women prefer sexual mates who are able to produce more complex music.
The study, published today in The Proceedings Of The Royal Society B, could account for the early origins of music, and why creative individuals are considered so desirable for short-term sexual relationships.
Benjamin Charlton, the paper's author, said: "The findings of this study provide the first support for Darwin's original contention that music evolved via sexual selection."
Dr Charlton's study of nearly 1,500 women, with an average age of 27.9 years, who were not breastfeeding, pregnant or using hormonal contraception, involved two experiments.
Women were asked to choose which of four thematically similar piano compositions, played by a MIDI sequencer (a music software application), was the most complex, Dr Charlton said.
The melodies progressed from a few chords and a simple rhythm to a greater variety of chords and a syncopated (off-beat) rhythm.
Another group of women were asked whether they would prefer the composer of the first simple or second more complex melody, either as a short-term sexual partner, or a longer-term partner in a committed relationship, Dr Charlton said.
The results showed that women only preferred composers of more complex music as short-term sexual partners when the risk of conception was at its highest, according to the study.
No preference was shown when women chose which composer they would prefer as a long-term partner in a committed relationship, the results revealed.
Control experiments on women's preferences for visual artists failed to show an effect of conception risk, Dr Charlton said.
He continued: "The ability to create complex music could be indicative of advanced cognitive abilities.
"Consequently, women may acquire genetic benefits for offspring by selecting musicians able to create more complex music as sexual partners."