There's more to what makes a man or woman attractive than mere shape or weight, but what else do we take into account when we make that judgement?
That's what a team of Sydney scientists is trying to find out and they're inviting internet users from all over the world to volunteer to help them by taking part in a unique scientific experiment.
At a specially created website - http://www.bodylab.biz/ - anyone can go online and make their own ratings of computer-generated images of men and women of greatly varying shapes, sizes and proportions. The images are produced with the same sophisticated software used in computer games and by fashion designers to create human avatars.
The bodyLab team will analyse and compile the results and each month they will cull about half of the images - those that are least popular - and virtually "breed" new body shapes from "parent" avatars with features rated as most attractive by people taking part in the experiment.
Over time, the scientists hope thousands of users will help them work through six or more "generations" of avatars to narrow down the special combinations of features that make up the "ideal" body - although they're keeping an open mind about whether several combinations will emerge.
bodyLab is a non-for-profit project based at the UNSW Evolution and Ecology Research Centre. It is the brainchild of Juliette Shelly and the centre's director, Professor Rob Brooks, who has a special interest in sexual selection, sexual competition and mate choice.
"Our judgments and decisions about attractiveness permeate almost all our social interactions as well as many commercial decisions that affect our lives," says Professor Brooks. "Despite all the novels, poems, films and love songs devoted to the subject, we know surprisingly little about attractiveness in a scientific sense.
"We've all heard experts talk about measures such as body mass index (BMI) or waist-hip ratio (WHR) and how they affect our perceptions of others. But obviously there's a whole lot more to attractiveness than numbers - people are attracted by a whole package of things.
"We are trying to understand how all the traits that make up a body combine to influence attractiveness. That would have scientific significance in its own right, but our results may also have useful real-world applications. It could help, for example, help people to choose clothes that best complement their bodies, or help people with body image problems see that there are many different kinds of attractiveness."
Rob Brooks - firstname.lastname@example.org
UNSW Faculty of Science media liaison - Bob Beale 0411 705 435 email@example.com