Is drinking together more fun? Study sheds light on the science of shared intoxication

Feeling more connected and enjoying conversations more is a common reason people drink alcohol in social settings. Now, research published in the journal Psychopharmacology provides scientific backing for this experience. The study found that alcohol enhances the enjoyment of social interactions and feelings of being connected to your conversation partner, regardless of whether they are also drinking. However, the positive experience of alcohol can be heightened when socializing with someone who is also under the influence.

Scientists have long known that people often use alcohol in social settings, possibly because it makes socializing easier and more pleasant. Alcohol is frequently consumed when people are together, yet most scientific studies on alcohol’s effects have been conducted with individuals in isolation. This means our understanding of how alcohol truly affects social interactions, and how social contexts alter our responses to alcohol, has been limited. It is important to understand how alcohol influences interactions between two people, especially when considering whether the other person has also been drinking, as this can help us understand why people use alcohol socially and potentially why misuse can occur in social situations.

Previous research has suggested that alcohol can make social interactions more positive when people are in groups. For example, studies have shown that in group settings, alcohol can increase social bonding, encourage smiling back and forth, make social experiences feel more positive, and even reduce the physical distance between strangers. However, many questions remained about how alcohol changes behavior in social situations.

One key question is whether the drug state of others involved in the interaction plays a role. Does being with someone who is also intoxicated make the positive experience of drinking alcohol stronger, or enhance the positive social effects of alcohol?

“My laboratory has studied the effects of psychoactive drugs in healthy volunteers for many years,” said study author Harriet de Wit, a professor of psychiatry and behavioral neuroscience at the University of Chicago. “The participants in these studies are typically tested under controlled double-blind conditions, under solitary conditions. Yet, these drugs are typically used in social settings, in the presence of others. This raises a question about whether, and how, the presence of others affects responses to drugs. In this study, we wanted to know whether the presence of an intoxicated partner would change responses to a moderate dose of alcohol.”

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Specifically, the researchers examined the effects of alcohol compared to a non-alcoholic placebo drink during a 45-minute casual conversation with a partner who also received either alcohol or a placebo. Before each session, participants were asked to avoid alcohol and recreational drugs for a certain period. They were told they might receive alcohol, a sedative, a stimulant, a hallucinogen, or a placebo, to keep them unaware of what they were actually given.

Thirty-seven healthy adults, 17 men and 20 women, aged 21 to 35, participated in the study. They were recruited from the local community through advertisements. Participants met specific health and lifestyle requirements, including being fluent in English, having at least a high school education, having a body mass index in a healthy range, not taking regular medications (except for birth control for women), and consuming a moderate amount of alcohol weekly. People with major mental health conditions, severe substance use problems, or pregnant women were not included.

Before the conversation, participants consumed beverages containing either alcohol (0.8 grams per kilogram for men and 0.7 grams per kilogram for women) or a placebo, which was designed to taste similar but contained only a small amount of alcohol as a taste mask. After consuming their drink, participants waited 30 minutes before engaging in their assigned conversation.

During and after the conversations, researchers measured various psychological and physiological responses. Participants completed self-report questionnaires assessing their subjective experience, including how much they liked the effects of the drink and how connected they felt to their partner. The researchers also used a machine-learning facial expression analysis tool to assess emotional expressions throughout the conversation, allowing them to track changes in emotion intensity in real time.

The results showed that participants who received alcohol reported feeling drug effects and liking the drug effects more than those who received the placebo. Interestingly, people reported liking the effects of alcohol more when their conversation partner also received alcohol, regardless of what they themselves had received.

After the conversations, those who drank alcohol reported feeling more elated, friendly, and energetic compared to those who drank the placebo. Alcohol also increased feelings of anger and confusion, but did not affect anxiety, depression, or fatigue. Alcohol made participants feel both more stimulated and more sedated. Most participants were able to correctly guess whether they received alcohol or placebo.

Regarding feelings of connection, alcohol made the conversations feel more enjoyable, and participants felt that their partners liked them more, that they had more in common with their partners, and felt closer and more connected to them. These feelings of connection were not influenced by whether the conversation partner had also consumed alcohol. Alcohol did not significantly change blood pressure or heart rate.

“In general, participants reported feeling the alcohol effects to a similar extent regardless of what the partner received, but they liked the effects more when the partner also received alcohol,” de Wit told PsypPost. “The study shows some of the ways in which the drug state of companions can influence responses to alcohol.”

Analysis of facial expressions revealed that alcohol increased positive emotions and decreased negative emotions during the conversations. Specifically, alcohol increased facial expressions associated with amusement, joy, and excitement, and reduced expressions of awkwardness and contempt. For women, this effect was more pronounced when their conversation partners had also received alcohol.

“We were surprised at the sex difference in facial emotions when the partner received alcohol,” de Wit said. “It suggests that women may be more sensitive to the drug state of people around them.”

The researchers noted some limitations. The sample size was relatively small, which limited the ability to explore sex differences in facial expressions in more detail. The participants were mostly light social drinkers from a similar background, so the findings may not apply to heavier drinkers or more diverse populations. “The findings would need to be replicated in other samples,” de Wit said.

The study is part of a broader line of research examining “the interactions between drugs and social contexts,” de Wit explained. “Social contexts can influence responses to drugs, and drugs can influence responses to social situations.”

The study, “Alcohol increases social engagement in dyadic interactions: role of partner’s drug state,” was authored by Hanna Molla, Tyler O’Neill, Evan Hahn, Royce Lee, and Harriet de Wit.