The big five traits openness and conscientiousness affect the memory of alcohol-intoxicated eyewitnesses

This novel study was the first to examine how alcohol and personality affect witnesses’ memory. Using a quasi-experimental method, participants (N = 65) recruited from local bars provided breath alcohol concentration measurements and personality ratings using Big Five (i.e., Openness, Conscientiousness, Extraversion, Agreeableness, Neuroticism). Participants viewed a filmed witness event, followed by an interview about the event. BAC ranged from 0.00-0.14 %, with a mean of 0.05 % (SD = 0.03 %). Results showed that there was a significant effect of Openness on the quantity of witness recall, with higher Openness scores yielding a greater number of witness details recalled. Also, participants with increased intoxication levels in combination with higher Conscientiousness scores reported fewer details. Finally, increased alcohol-intoxication had a negative effect on memory as witnesses’ accuracy rate declined, while their number of “I do not know” answers increased. Our findings suggest that personality differences may play an important role in alcohol-intoxicated witnesses’ episodic long-term memory, despite being largely neglected by researchers. Future research is encouraged to continue disentangle the complexity of the interaction between personality, alcohol, and witness memory.