“I wouldn’t trust a man who doesn’t drink” is one of the sillier Australian expressions, but its currency helps explain why some journalists think Kevin Rudd may not be harmed politically by his escapade in New York.

In The Lucky Country, published in the sixties, Donald Horne wrote, “to drink is one of the tests of manliness,” and many of Australia’s popular satirical characters are boozers: Sir Les Patterson, Barry McKenzie, and Alf Cook in the Anzac Day play, The One Day of The Year. For them, and the men for whom they are models, a drinker is a good bloke and a non-drinker is suspicious.

Most Australians –about 85%– are “current drinkers”, defined as having consumed alcohol at least once in the past 12 months. Of course, many of them drink rarely, and many others moderately; but it is not uncommon for drinkers to consume too much and suffer a temporary blackout, as reported by Rudd.

His greatest vulnerability lies in his being unable to defend himself were he to be accused of improper behavior at the time of the blackout. As he can’t remember, he can’t be sure what happened. He is fortunate that his two companions vouch for his behavior.

Some authorities suggest up to 40% of social drinkers at some time experience a short term blackout as a result of drinking. It is temporary amnesia, caused by acute intoxication or drunkenness, the result of drinking a large amount in a short time.

It is thought a heavy concentration of alcohol in the brain disrupts the formation of short term memories. The duration can vary from a few minutes to hours. The person may appear normal, or may be obviously drunk. Sometimes the entire period remains permanently lost to memory, sometimes snatches of the past return; but gaps remain.

How much alcohol is required for an individual to blackout temporarily is difficult to predict, as it will depend on their tolerance to alcohol. An occasional or light drinker will be affected more easily than a regular or heavier drinker.

Alcohol specialists report ten to twelve standard drinks within a couple of hours are usually needed to produce memory gaps, but occasional drinkers might need only a few drinks. Blackouts among light drinkers might signify their drunken state is a rare occurrence and protect them from becoming a heavy drinker.

Kevin Rudd’s experience gives the lie to the alcohol industry’s argument that most drinkers drink “moderately” and therefore do not have to worry about alcohol-related trouble. The industry pretends that only a minority of dependent drinkers are at risk of harm, so the rest of us can get on with it.

The reality is that people who usually drink within bounds are prone to overdoing it when the occasion beckons. None of us should consider ourselves entirely safe when it comes to drinking. Kevin can vouch for that.