"In one study, over 700 male and female social drinkers were divided into groups of three strangers and instructed to drink for 36 minutes."

"The participants thought the drinks were a prelude to the experiment, but researchers were observing what they did at the table. Initially, the strangers did not smile much. But as they consumed their vodka cranberry drinks, their expressions changed. They not only smiled more, but also caught each other’s smiles, and spoke more in succession. And they shared more of what researchers called 'golden moments' when all three strangers smiled as one...."

From "Why do people like being tipsy? Here’s how alcohol affects the brain. The buzz produced by alcohol comes from a cocktail of pharmacology and social ingredients, research shows" (WaPo).