Why we salivate at objects of desire

“One possibility is... that all objects of desire, whether biological or non-biological, activate the same general reward system in the brain,” writes author David Gal of Northwestern University.

Gal measured salivation by having participants put cotton dental rolls in their mouths while they gazed at pictures of money. He later weighed the rolls to measure the amount of saliva, the Journal of Consumer Research reports.

Before they viewed money, however, Gal prepared the participants to feel powerful or powerless, according to a Northwestern statement.

“This suggests that people salivate to non-food items when those items are desired to fulfil a highly active goal,” Gal writes.

Gal wondered whether men would salivate to high-end sports cars.

In this case, he induced some of the men to have a “mating goal,” because prior research shows men who want to impress women purchase luxury goods.

Gal showed the men photographs of attractive women and asked them to choose one they would like to date.

He asked the other group of men to ponder a visit to the barber.

The men with the active mating goal salivated more at images of high-end sports cars than the men who had been prompted to imagine getting a haircut.