Singles who want children tend to find older people more attractive - but not for their money, according to a new study.
Researchers found that heterosexual adults keen to become moms or dads are more attracted to older people, although financial factors and perceived parenting ability didn't influence the preference.
Participants in the study who self-reported a stronger desire to have children showed a weaker preference for younger faces compared to those with a weaker desire to have children.
Jingheng Li and his colleagues from the University of Strathclyde, Glasgow, found the preference was unrelated to the potential partners' perceived wealth or parental prowess.
Researchers have often examined the foundations of attractiveness -- the intangible "it" factor that tempts voters, procures job offers and allures romantic partners.
Men tend to associate attractiveness with youthful features, presumably for reasons related to reproduction.
Doctoral student Li and his colleagues put that theory to the test by asking 149 men and 151 women, average age 30 and 31 respectively, to rate 50 headshot pictures of the opposite sex on a scale of "not at all attractive" to "very attractive."
All the participants in the study, published in the journal PLOS One, were heterosexual UK residents with no children who spoke English as their first language.
The subjects in the headshots ranged from 19 to 55-years-old.
All the participants completed a "desire to have children" questionnaire.
Li said: "In general, participants rated younger adult faces as more attractive than older adult faces, and men and older participants rated faces as more attractive than women and younger participants."
Based on two subsequent studies with new participant groups, the researchers observed that the older-looking headshots were not perceived as wealthier or more capable parents than their younger counterparts.
Li added: "Our study challenges a widely held assumption in evolutionary psychology.
"We found that men and women who reported a stronger desire to have children actually showed weaker preferences for younger adult faces, offering no support for the idea that reproductive motivation drives stronger attraction to youth."
The research team hope to learn more by examining additional factors, such as whether participants already had children, how they accessed and used contraceptives plus other cultural and social differences