Study: Hard to Tell Who Is Drunk

June 18, 2001 -- It can be hard to tell if someone has been drinking too much todrive.

A new study says even “trained professionals," such as police officers, werenot always able to assess drunkenness when they screened a videotape ofdrinkers.

“When people are far too intoxicated to drive they might not appear to beintoxicated by casual observation," said the study’s lead author, biologicalpsychologist John Brick . Brick is the executive director of IntoxiKon, aPennsylvania-based company that provides research and education on drug and alcohol use.

Brick called it "interesting" that “highly trained individuals, policeofficers, were like other people and didn’t [simply by observing] possessthe ability to identify someone" who was intoxicated until blood alcohol levels are quite high.

Videotaped Interviews

In the study, New Jersey police officers were shown videotaped interviewswith seated drinkers at low (0.08 to 0.09), medium (0.11 to 0.13) and high(0.15 to 0.16) blood-alcohol levels. The officers were then asked questionsabout the subjects’ levels of intoxication and how confident they were in their ratings thatthese drinkers could be allowed to drive.

The officers could only consistently discern intoxication when blood levelsexceeded 0.15 percent. Below that level, many officers made incorrectjudgments.

President Clinton signed legislation in October 2000 that provided incentivefor states to adopt 0.08 percent blood-alcohol concentration as the standardfor drunken driving. So far, 25 states have adopted the incentive; mostother states have a 0.10 percent law.

The study results were consistent with other studies Brick has done. Itappeared in the June issue of the journal Alcoholism: Clinical &Experimental Research.

Police Capable of Assessing Drunken Drivers in the Field

Brick stresses in the study, “These results should not be interpretedto mean that police officers cannot make decisions about drunk drivers."

Inthe field, police have many other tools at their disposal, such as fieldsobriety tests and roadside breath tests.

Because the study allowed only the observance of videotaped conversationswith seated subjects, the rating officers were deprived of other importantcues, including the odor of an alcoholic beverage, any admissions of alcoholuse and the opportunity to observe standing and walking behaviors.

Bartenders, Friends May Be at a Loss, Too

Brick points out that the test environment was more analogous to whatbartenders and social hosts might face when serving drinkers who aresitting down. He says if police officers can’t tell in that setting ifsomeone is drunk just by observation, how can a bartender or a friend knowwhen to take the keys away from someone who has been drinking too much?

“This type of example is what might happen in a bar or in someone’s home,"Brick said. “People just don’t have the ability to know when someone is toodrunk to drive just by observing, unless there is slurred speech orswaying." In the absence of testing, such behaviors do not reliably appear in most drinkers at the lower blood alcohol concentrations used in this study.

But, given their ability to perform intoxication tests, police may have abetter chance at assessing someone’s status than a bartender or friend.

“Observing casual conversation may not be adequate to judge balancedexterity, pupil dilation, or even flushness," said Edward Sponzilli, anattorney cited in in a news release provided by Brick’s organization. Sponzilli is familiar with the research and this area of law.

“These limitsare not inconsistent with the context in which a social host, bartender orpotential passenger may observe," he said.

Some state laws make it a crime to give one’s car to an intoxicated person.In New Jersey, for example, the law imposes a duty not to entrust the car toa person whose blood-alcohol level is 0.10 percent or higher.

“If an alcohol influence is found, then the car owner may face a six-monthto a one-year loss of license," Sponzilli said.

Earlier this year, a Salem, N.J., man was charged with manslaughter after helet his drunken friend drive his car. The two got into a deadly wreck inwhich the drunken driver and an innocent bystander were killed.

The bottom line, Brick said, is that, if concerned, bartenders and friendsshould err on the side of caution. People who may not look impaired maystill be too drunk to drive safely, and those who do look impaired are probably far too intoxicated to be behind the wheel and are simply too intoxicated to drive safely.