A new study of students and prison inmates published in Personality and Individual Differences by researchers from the Johann Wolfgang Goethe University in Frankfurt found a connection between wider facial structure and psychopathy, according to the Daily Mail. In addition to psychopathy, this trait is also linked to attraction and aggression.

The study found that those with a higher width-to-height ratio were more likely to exhibit "self-centered impulsivity," "fearless dominance" and a tendency to blame other people for problems, all characteristic of those with psychopathy.

The researchers said that one of the biggest impacts on face width in men is testosterone exposure during puberty.

"Without doubt, testosterone has long-lasting effects on the brain, particularly during sensitive developmental periods such as puberty," they said. "The affected brain regions include the amygdala and the hippocampus, limbic structures that are crucially involved in socio-emotional behaviour.

"Notably, these two regions are among the core regions for which structural and functional brain abnormalities have been reported in psychopathy."

This is not the first study to provide results that point in this direction; a study conducted last year found that both men and women with wide faces tend to exhibit more aggressive, dominant and angry behaviors than those without.

Psychopathy can be detected as early as age 3, according to The Sydney Morning Herald, and is characterized by unreliability, untruthfulness and an inability to feel remorse.

In addition to facial structure, speech patterns have also been linked to psychopathy, according to Live Science. Those with higher psychopathic scores showed a lack of emotion when describing their crimes and an increased focus on their basic needs such as food and money.