London, Aug 20 (IANS): Tall masculine men who are around 35 years of age are perceived to be the most dominant, says a new study.

"Understanding what influences dominance perceptions is important since a dominant appearance in male faces is associated with a variety of social outcomes,” said lead researcher Carlota Batres from University of St Andrews in Scotland.

"Dominant people are favoured as leaders during times of intergroup conflict and are more successful leaders in the business world. Hence, understanding what it is that makes someone look dominant is important given its influence on a variety of social outcomes," Batres noted.

The researchers used computer graphic manipulations to make subtle alterations to images of men's faces.

Participants in the study were asked their opinions on the men, based on how tall, masculine and old they appeared to be.

When the researchers made 25-year-old men look eight cm taller, up to a decade older, or made their faces more masculine (by for example increasing the prominence of their eyebrows), the onlookers thought the men looked more dominant.

Maximum dominance was achieved by increasing perceived height and masculinity while maintaining a man's age at around 35 years.

The findings also provide some insight into casting choices made by film directors, since male leading roles are often played by actors who fit the dominance description in the study.

The research was published in the journal Perception.