STEALTH TACTICS: Saying hello to friends and acquaintances on the street may seem like the obvious and polite thing to do, but a new report shows it may be costing us dearly.

Social researchers from the University of Technology interviewed 3000 Australians, finding they spend up to 2 days per year bumping into people they know.

The report found many people feel forced to say hello, even if they don’t feel like it.

“Avoid this trap,” says researcher Michael Cramer. “Most of the time they don’t want to say hi to you either.”

Sydney’s Jan Schroeder says the key is to dodge eye contact at all costs.

“I always pretend I don’t see them, but the truth is I always spot them coming from a mile off,” she says.

“As they get closer, just pretend to be looking at your phone,” she says. “It works a treat.”