Aggressive people are easy to spot because they have instantly recognizable wide faces, researchers claim.

Just a quick glance at someone's facial structure may be enough to predict their tendency towards aggression, according to a study published in the Psychological Science journal found

Facial width-to-height ratio (WHR) is determined by measuring the distance between the right and left cheeks and the distance from the upper lip to the mid-brow.

Psychologists from Brock University in the USA decided to follow up on previous research that suggested males with a large facial WHR act more aggressively than those with narrower features .

In the study, volunteers viewed photos of faces of men who had previously had their aggressive behaviour analysed.

The participants then rated how aggressive they thought each person was on a scale of one to seven, after viewing each face for either 2000 milliseconds or 39 milliseconds.

The results revealed the participants' estimates of aggression correlated highly with the actual aggressive behaviour of the men - even if they only saw the picture for a split second.

And the volunteers' estimates also matched with the WHR of the faces the wider the face, the higher the aggressive rating.

The psychologists concluded that subtle differences in face shape may affect personality judgements, which in turn, guide how people respond to others.

During childhood, boys and girls have similar facial structures, but during puberty, males develop wider features than females.

Previous research has suggested that males with wider faces act more aggressively - with studies showing that hockey players with broad features earn more penalty minutes per game than other players .

(Read by Chantal Anderson. Chantal Anderson is a multimedia journalist at the China Daily Web site.)

(Agencies)