BOGOTÁ — Can voters be swayed by a candidate's face? If they're young and undecided, then yes, researchers in Colombia have found.

Psychologist Henry Castillo Parram, in collaboration with the firm Neuromind, selected 180 eligible voters from Bogotá and Medellín, all aged 18-24, and showed them pictures of the five main candidates for the country's recent first-round of presidential election, on May 27.

The candidates include leftist former mayor of Bogotá Gustavo Petro, Humberto de la Calle, a veteran official who led peace talks with the FARC guerrillas, former Medellín mayor Sergio Fajardo, and the centrist Germán Vargas Lleras. (By Monday, the election appeared set for a tight run-off next month in the race to succeed departing President Juan Manuel Santos.)

Researchers showed a random selection of images of the candidates — in mosaics, black and white, or color — and used eye tracking and face reading technologies to scan the subjects' reactions.

"The human brain is sensitive to human faces," says Castillo. "It is genetically coded for that. So when people have not yet defined their vote and do not know about proposals, they rely on biological and automatic criteria caught by the brain." Facial symmetry, he adds, generates hormones that can prompt "emotional attachment."

It is genetically coded for that.

The scans identified seven feelings among respondents: happiness, sadness, wrath, surprise, fear, distaste and contempt. Fajardo, who worked as mayor to make Medellín more user-friendly, generated a 23.7 happiness score out of 100 (compared to 7.9 for Vargas Lleras). Fajardo also scored well in terms of generating trust, with 25/100.

The subjects found de la Calle to be the most "depressing" of the candidates, with a 43.4 sadness score, and Petro the least. A no-nonsense socialist, Petro is doing well in polls in spite of his troubled spell as mayor.

Humberto de la Calle — Photo: El Espectador

The "establishment" candidates Vargas Lleras and de la Calle fared worst over all in the facial tracking study. "[Vargas Lleras] earned the most negative scores from the emotional aspect," says Castillo. Both candidates, he adds, failed to "activate the neurons" of the young would-be voters.

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