Researchers in Scotland have found that the hormone testosterone affects who women and men are attracted to.
The researchers from the Face Research Laboratory at Aberdeen University say when women's testosterone levels are high they are drawn to masculine actors such as Daniel Craig, the current James Bond.
When men's testosterone levels are high they are attracted to feminine women such as Natalie Portman and Evangeline Lilly.
The researchers claim that changes in testosterone levels affect the extent to which men and women are attracted to different types of faces, rather than people being attracted to particular types.
The researchers say people preferred different types of face in the sessions where their testosterone level was highest than in the session where it was lowest.
The researchers asked male and female volunteers to complete short face preference tests in which they were shown pairs of masculine and feminine faces - they were asked to choose which face from each pair was more attractive.
They completed four different test sessions that were each a week apart and in each session, the volunteers also provided a saliva sample which was used to measure testosterone levels.
Psychology lecturer Dr. Ben Jones, says when men's testosterone levels were high, they were more attracted to feminine women and when women's testosterone levels were high, they were more attracted to masculine men.
Dr. Jones says since masculine men and feminine women are thought to produce the healthiest children and sex drive is higher when testosterone levels are also high, these findings suggest that men and women in hormonal states, where their interest in sex is highest, show stronger attraction to high quality - or healthy - mates.
Researcher Dr. Lisa Welling says the research shows that attraction is affected by fluctuations in testosterone levels and is not a stable effect over time.