The Duggars are definately fans of teaching life lessons, even if they don't call them that, I do. They teach by example and then remind their kids of that example and how they can apply those lessons in their own individual daily lives.
The value of a kind deed is something the Duggars taught the kids by explaining an experience Jim Bob had when he was just a young boy. As they explained in their book, Jim Bob did not grow up in a family that always had enough money to go around. There were times when they didn't have enough food to eat or enough food to eat, let alone money to pay for a haircut for Jim Bob. His mother would attempt home hair cuts and they didn't always turn out with successful results. They show a picture of a small Jim Bob with one such haircut and while not being horrible, it wasn't great either. Apparently the Duggars had a neighbour who was a hair stylist. She offered to cut Jim Bob's hair for him for free. While this was something easy for her to do and give, it made a huge impact on Jim Bob. He describes the change in his self-image and his self-esteem. You do seem to do better when you feel better about yourself, don't you?
Jim Bob and Michelle remind their kids that there are so many small things they can do for other people, that might not seem like anything to them, but could have a lasting effect on the person they do the good deed for. In Judaism we refer to doing good deeds as performing "mitzvahs." There are so many things we do for other people that we don't even consciously see that someone else could see as a good deed--from letting a car go in front of you in traffic or picking up something that someone dropped and handing it to them. These little things may not stick in your mind for any longer than it takes to do them, but who knows how long the person you do it for remembers. And it's quite likely that they may spread the good deed on to others by following your example.
Think of the good deeds others have done for you and the effect it's had on you. Remember to pass it on and share that wisdom with your children or other family and friends. More good deeds can only make the world a happier place.