Scientists have found that feelings play a key role in determining from which side we hug each other.
Hugs are part of social interactions between humans since birth. They express affection and love, and they occur in both positive and neutral contexts.
In emotionally charged situations, people tend to hug each other from the left side more often than in neutral contexts, said the researchers from the Ruhr-Universitat Bochum in Germany.
They observed that predictions about which hand will be on top during an embrace can be based on the participants' handedness and footedness.
"We wanted to know if the hug-related behaviour is affected by the emotional context of the give situation," said Julian Packheiser, from the Ruhr-Universitat Bochum.
"Moreover, we wanted to find out if motor characteristics such as handedness determine the lateralisation of the embrace," Packheiser.
For the study published in the journal Psychological Research, the researchers studied more than 2,500 hugs.
In order to study neutral embraces, the researchers analysed 500 clips of actors who offered blindfolded hugs to strangers in the street.
Consistent with older studies, the researchers determined that most people show a preference for right-sided hugs.
At the same time, it emerged that left-sided hugs occur more frequently in positive as well as negative situations.
"This is because of the influence of the right hemisphere, which controls the left side of the body and processes both positive and negative emotions," said Packheiser.
"When people hug, emotional and motor networks in the brain interact and cause a stronger drift to the left in emotional contexts," Packheiser said.
To investigate the influence of handedness and footedness, the researchers subsequently asked 120 test participants to hug a mannequin after listening to various positive, negative and neutral short stories via headphones.
Right-handed people tend to hug the other person from the right side, much more often than left-handed people, Packheiser said.
"Our interpretation is that many men consider embraces between men to be something negative; therefore, they tend to perceive hugs as negative even in a neutral situation, such as saying hello," said Sebastian Ocklenburg, from the Ruhr- University Bochum.
Accordingly, the right hemisphere is activated due to negative emotions and affects the motion to the left, he said.
