Dr. Phil Shares His Secret to Marriage and the Biggest Issue Facing Relationships Today (Exclusive)

After over 40 years of marriage, the TV icon knows what he's talking about.

After over 40 years of marriage to his wife, Robin McGraw, Dr. Phil knows a thing or two about successful relationships. 

ET's Lauren Zima sat down with the TV icon on Thursday, where he revealed the simple trick to a happy marriage. 

"One is, don't let things stack up. Deal with them as they come. I think that's really important," Dr. Phil shared. "Second, if you have a disagreement, make it your goal to be heard and understood, rather than agreed with." 

"If you go into an argument and your goal is you're going to get your partner to agree with you, you've made it win/lose. And you don't want your partner to be a loser. You don't want that to happen," he explained. "So what you do is make it your goal 'I just want you to hear me. I just want you to understand me and then do with that what you will'...When you do that, you find that the other person tends to come to your direction a whole lot more than if you're pounding your point until they agree with you."

While relationships have no doubt evolved over the years, with technology sometimes helping and hurting romances, Dr. Phil believes that what hasn't changed throughout time is "devoting time to one another, and shutting out the noise from the rest of the world." 

"I always tell people to make time for each other. whether it's a date night or an hour through the day," he advised. "The stranger that feels, the further you've drifted away from what brought the two of you together. You need to remember and focus on why you feel in love with that person to begin with." 

"If you wake up everyday and ask yourself, 'What can I do today to make my spouse's life better?' It'll change the course of your [relationship]," he continued. "It doesn't have to be something big. You don't have to go buy them a diamond ring. You don't have to go buy them a set of golf clubs. It could be a little note in their pocket. It could be something simple. 'What can I do today to make things better?'"

"A little selflessness," he concluded. 

New episodes of Dr. Phil air daily; check your local listings!