Study confirms alcohol consumption increases aggression


People drink alcohol on various occasions in their lives. They may drink to celebrate their birthdays or to release a long week’s stress on a Friday night. However, scientists have become more aware that drinking alcohol is linked to aggression. Half of all violent crimes are the result of alcoholic intoxication, according to the study “The neural correlates of alcohol-related aggression” published in the journal “Cognitive, Affective, & Behavioral Neuroscience.”

Studies such as “Evidence for a different role of the ventral and dorsal medial prefrontal cortex for social reactive aggression: An interactive fMRI study” and “Tit-for-tat: The neural basis of reactive aggression” have conducted fMRI scans of the brain and found an increase in aggression and violence after drinking alcohol. The brain scans show that people get aggressive after only a drink or two. This is because there are changes in the prefrontal cortex, the part of the brain directly related to a person’s aggression. The study published in the journal “Cognitive, Affective and Behavioral Neuroscience” is further confirmation that drinking alcohol affects the brain and increases aggression.

The prefrontal cortex is the front part of the brain, making up roughly 8 percent of the entire brain. It is directly linked to a person’s personality, decision-making abilities and moderation of social behavior. For this study, it is important to note that the prefrontal cortex moderates the levels of aggression in people.

To conduct the research, 50 healthy, young men were given either two drinks containing vodka or placebo drinks that did not contain any alcohol. The men were also given $75 in exchange for participating in the study. They were screened to make sure they did not have any mental or physical health ailments, or life-threatening reactions to alcohol. All the selected men were also screened to make sure they only drank three times or less each month.

This experiment is used to understand the effect of alcohol consumption on aggression and has been used for the past 50 years. Participants were asked to complete a task in which they competed against other participants. While repeatedly pressing a button on a screen,  participants were given the opportunity to send noise blasts that were either low or high to their opponent.

The hypothesis being tested was that aggression would increase under the highly provocative situation of the opponent sending louder noise blasts to the participant. FMRI scans were taken while conducting this experiment. The results showed that, despite the provocative situations, it was alcohol that played a greater role in more aggressive decision-making.

The fMRI scans focused on six different regions of interest: the hippocampus, caudate, thalamus, ventral striatum and amygdala. Participants who drank alcohol had an increase in blood oxygen level-dependent responses in their hippocampus, the brain region associated with memory, emotions and learning. There was also a decrease in BOLD responses in the prefrontal cortex, caudate, a brain structure linked to inhibitory control of action, and ventral striatum, a brain structure linked to reward processes and motivation.

In simpler words, those who consumed alcohol were more aggressive regardless of how provocative the situation was.

A crucial fact that the study may have left out is one that Zach Sapolsky — a psychology professor at Baruch College and clinical psychologist — noted: the prefrontal cortex is not fully developed until  one is 25 years old, which means that drinking alcohol at any age under 25 is damaging a crucial part of one’s brain. That is why Sapolsky said that people should wait until they are 25 to drink alcohol because they could mess up their personalities, adding,  “Many of you are probably thinking, ‘too late for that!”