A new Yale-led study confirms that beauty is indeed in the eye of the beholder.

The study asked both plastic surgeons and the general public about the ideal shape of lips and chin. Researchers found opinions on the matter are not universal, uncovering that preferences are influenced by demographic, geographic and ethnic factors. The study, which appeared in the Journal of Craniofacial Study in March, impresses the importance of doctors listening to patient preferences during facial reconstructive surgery, said John Persing, a professor of surgery at the Yale School of Medicine.

“It is important to recognize that plans for surgical procedures on the face should be individualized,” Persing said. “Because [of] these biases, the patient should be clear as to what they, personally, want to see changed, and not to rely on just what the doctor says he [or] she should have done.”

In the study, participants modified a digital image of a face by augmenting or reducing the projection of the lips and chin, the same adjustments performed by plastic surgeons during aesthetic reconstructive surgery. The survey yielded 1,226 responses from over 50 countries.

Researchers uncovered that preferences among plastic surgeons across the world differed from the general population. Surgeon preference usually aligned with a singular idea of beauty consisting of symmetrical nose and lips — the so-called “golden ratio” portrayed by Leonardo da Vinci, among others.

Among the general population, sex, occupation and ethnicity were found to be significant in establishing ideal chin projection. Among white and Hispanic participants, females preferred a greater degree of chin projection than males. Caucasian and Hispanic respondents also preferred a less prominent chin than surgeons.

“‘Ideal’ aesthetics are highly dependent on the individual’s cultural and ethnic background and cannot simply and solely be defined by numeric values and divine proportions,” said Yuen-Jong Liu, a study co-author and chief surgical resident at Beth Israel Deaconess Medical Center in Boston.

The study focused solely on facial aspects of beauty, and Liu said other studies of beauty have found less varied ideals. For instance, Liu said, a recent study on breast implant surgery found that breast size is one of the more universal preferences.

Study authors write that the findings call for surgeons to be more sensitive to differences in patient preferences of beauty during aesthetic facial plastic surgery or a breast reduction procedure.

Reuben Ng, a study co-author and doctoral candidate at Yale, said the finding that perception of beauty depends on culture calls for further study of how cultural differences manifest in everyday lives.

According to the Centers for Disease Control and Prevention, somewhere between 60,000 and 750,000 people travel to a different country for medical treatment each year.