Houston: There may be no such thing as 'happy drunk', say scientists who have found that alcohol does not radically change personality.
People typically report substantive changes to their personality when they become intoxicated, but observations from outsiders suggest less drastic differences between "sober" and "drunk" personalities, researchers said.
"We were surprised to find such a discrepancy between drinkers' perceptions of their own alcohol-induced personalities and how observers perceived them," said Rachel Winograd of the University of Missouri, St Louis in the US.
"Participants reported experiencing differences in all factors of the Five Factor Model of personality, but extraversion was the only factor robustly perceived to be different across participants in alcohol and sober conditions," said Winograd.
Researchers recruited 156 participants, who completed an initial survey gauging their typical alcohol consumption and their perceptions of their own "typical sober" personality and "typical drunk" personality.
Later, the participants came to the lab in friend groups of three or four, where they administered a breathalyser test and measured the participants' height and weight.
Over the course of about 15 minutes, each participant consumed beverages - some drank a soft drink, while others consumed individually-tailored vodka and soft drink cocktails designed to produce a blood alcohol content of about .09.
After a 15-minute absorption period, the friends worked through a series of fun group activities - including discussion questions and logic puzzles - intended to elicit a variety of personality traits and behaviours.
The participants then completed personality measures at two points during the lab session. And outside observers used video recordings to complete standardised assessments of each individual's personality traits.
Researchers found that participants' ratings indicated change in all five of the major personality factors.
After drinking, participants reported lower levels of conscientiousness, openness to experience, and agreeableness, and they reported higher levels of extraversion and emotional stability (the inverse of neuroticism).
The observers, on the other hand, noted fewer differences across the sober and intoxicated participants' personality traits.
The observer ratings indicated reliable differences in only one personality factor: extraversion. Specifically, participants who had consumed alcohol were rated higher on three facets of extraversion: gregariousness, assertiveness, and levels of activity.
The study was published in the journal Clinical Psychological Science.