Two signals were necessary to ensure timely service. "First, the customers position themselves directly at the bar and, secondly, look at the bartender," said Dr Loth.
"If one of these signals was absent, the participants judged the customers as not bidding for attention."
Auckland bar manager David Wilkinson was unswayed by psychologists' advice though. After 15 years' experience in the hospitality industry he agrees eye contact helps, but says it is the job of bar staff to try to assess who has been waiting longest rather than succumbing to pushy patrons.
"I don't like people pushing in or calling out for a drink from the end of the bar," he said yesterday afternoon, between taking orders at the Shakespeare Hotel and Brewery.
"People who try to push in don't get anywhere - not when I'm serving, anyway."
He said he wasn't influenced by gender or height, and his preferred way of dealing with the stroppy minority was to "just grin and smile".
At the same time, he always tried to stay alert and keep an eye on people entering the bar, to intercept anybody too intoxicated to serve and suggest politely they go elsewhere.
David's top five hates
1. Stroppy patrons trying to push in between those who have been waiting longer for drinks.
2. Intoxicated patrons demanding unsuccessfully to be served.
3. Patrons calling out for drinks from the other end of a bar.
4. Gamblers demanding change for pokie machines from bartenders busy pouring drinks.
5. Patrons who can't make up their minds what to order while keeping others waiting.