“Everyone lies,” Greg House, M.D., famously declared in his role as the Sherlock Holmes of diagnostic medicine. Who would disagree that even the saints among us might tell a tactful lie on occasion?

But all humans all have a strong motivation to maintain consistency between their words and actions. And that’s true both publicly and privately. When we say one thing and do another we feel a sense of uneasiness. Social science calls that cognitive dissonance. It’s a feeling that people will go to great lengths to avoid.

You can use people’s universal urge to act in accordance with their verbal commitments when you’re scheduling meetings with your prospects – and avoid having to deal with those no-show situations we all hate. Here’s what to do.

Next time you’re on the phone scheduling a sales meeting, tell the prospect, “We all know that sometimes things come up that might make it necessary to reschedule this meeting. If you’re not able to keep the appointment, will you please call me the day before and let me know?” Then wait for the other person to voice their agreement. Make sure they’re being clear and specific.

You can further hedge your bets by sending a confirming email and asking the prospect to write back and confirm the details. The stronger the agreement, the less likely that prospect will want to renege on his commitment by blowing off the meeting.

This of course won’t guarantee that no one will call or write to reschedule or even to cancel the meeting entirely, but it essentially does away with unexpected no-show appointments.

Studies of restaurant reservations have shown that no-shows on busy weekend nights dropped drastically when patrons made clear commitments that they’d call and cancel their reservations if they were not going to be there at the designated time.