Today, I’ve asked Uri Gneezy to share his Tip of the Week. 

When my son Ron was young, I told him not to lie—being honest is what separates the good guys from the bad guys. But this lesson soon got me into trouble. 

One day, I took Ron to Disney World, and as we waited in line to purchase tickets, I saw a sign that said, “Under three years old: Free. Three and older: $117.” 

When it was our time to pay, the cashier asked me how old Ron was, and I replied, “Almost three.” Technically I wasn’t lying: He was almost three, but from the wrong side. His third birthday was a few months earlier. 

A couple of minutes later, Ron said, “Daddy, I’m confused. You told me only bad guys lie, and you just did.”

I was caught. What message did I just send my kid? I told him one thing—don’t lie—but acted differently in the face of a $117 incentive, sending a mixed signal. 

You can tell everyone that you care about honesty, but talk is cheap. To avoid sending such mixed signals to your kid, you need to set up strong consequences in advance. For example, if you want to convince your teen that texting while driving is a really bad idea, you would make the categorical decision never to touch your phone in the car. And you’d set a punishment—say, your children can report you to your spouse—if you do. 

After three-year-old Ron saw me sneak him into the park for free, he learned a lesson—just not the one I wanted to teach. When we got to the Dumbo ride, which was restricted to ages four and up, he told the operator he was four and, therefore, old enough to go on the ride. Not surprisingly, he learned from the wrong signal. 

Don’t believe that just telling kids to do the right thing will be effective.  

Do use incentives to help yourself model ethical behavior. Put money in a jar to donate to charity if you curse or when you’re late for an appointment. Your actions send a signal about what you really care about, and your kids are observing your signals. 

With honesty and gratitude,

UriUri Gneezy is the Epstein/Atkinson Chair in Behavioral Economics at the University of California San Diego’s Rady School of Management and the author, most recently, of Mixed Signals: How Incentives Really Work.