Contact Us for a Consultation (907) 891-1852

Alaska DUI Digest

Understanding the Mellanby Effect:

Posted by John Roberson III | Feb 15, 2024 | 0 Comments

Understanding the Mellanby Effect: A Critical Insight for Safe Driving

Driving under the influence of alcohol remains a significant legal and safety concern across the globe. A fascinating aspect of alcohol consumption, known as the Mellanby effect, sheds light on the discrepancies between subjective feelings of intoxication and objective impairment. This phenomenon suggests that the effects of alcohol intoxication feel more intense when blood alcohol concentration (BAC) is on the rise compared to when it's at the same level but decreasing. This understanding is not just academic—it has real-world implications, especially for drivers who might underestimate their impairment.

The Science Behind the Mellanby Effect

Research supporting the Mellanby effect indicates that individuals report feeling more intoxicated and are more likely to overestimate their ability to drive when their BAC is climbing. Surprisingly, this subjective feeling changes as the BAC starts to fall. At the same ethanol concentration, individuals may feel less impaired on the downward slope of their BAC, leading to a dangerous misjudgment of their driving capabilities.

However, objective assessments tell a different story. Critical skills for safe driving, such as reaction to inhibitory cues and performance in driving simulators, actually show more impairment during the decreasing phase of BAC than when it is increasing. This discrepancy means that although someone may feel more sober as their BAC lowers, their physical and cognitive abilities do not recover as quickly.

A Real-World Analogy

To put this into perspective, consider driving at 45 mph on a feeder road before accelerating to 65-70 mph on the freeway. Upon exiting back to a feeder road and slowing down to 45 mph, the speed feels significantly slower than initially perceived. This mirrors the Mellanby Effect, where the initial feeling of impairment becomes a flawed benchmark for sobriety as intoxication levels rise and then fall.

The Importance of Objective Measures in Determining Impairment

The Mellanby effect underscores a critical message for all drivers: subjective feelings of sobriety are unreliable. The sensation of being "less drunk" as time passes might not accurately reflect one's driving abilities. This discrepancy highlights the importance of relying on objective measures, such as BAC levels determined by breathalyzers or blood tests, rather than personal judgment, to assess one's fitness to drive.


Understanding the Mellanby effect is crucial for anyone who chooses to drink. It emphasizes the danger of drinking and driving, pointing out that the only safe option is to not drive at all if you've consumed alcohol. For those facing legal issues related to DUI charges, it's important to consult with a knowledgeable criminal defense attorney who can navigate the complexities of your case with this scientific insight in mind.

About the Author

John Roberson III

10+ YEARS OF COMBINED CRIMINAL DEFENSE EXPERIENCE 35+ CRIMINAL JURY TRIALS 500+ CASES ANDCHARGES RESOLVED 18+ YEARSIN ALASKA Experienced & Aggressive Criminal Lawyer About Law Office of John H. Roberson III, LLC John brings diverse experience, dedication, and legal knowledge to each ca...


There are no comments for this post. Be the first and Add your Comment below.

Leave a Comment

Contact Us Today

Law Office of John H Roberson III is committed to answering your questions about Criminal Defense law issues in Anchorage, Alaska. We offer consultations and we'll gladly discuss your case with you at your convenience. Contact us today to schedule an appointment.

The information provided on this website is for general informational purposes only and is not intended as legal advice. No attorney-client relationship is formed through the use of this site. Each legal situation is unique; therefore, you should consult with an attorney directly regarding your specific circumstances. The content of this site may not reflect current legal developments and is subject to change without notice. We disclaim all liability for actions you take or fail to take based on any content on this website.