There is a sweet naivete to a study like this, it invites compassion.
Analyzing happiness with this cold academic rigor is just absurd, it is like a depressed species of alien studying our planet to figure out why people have happy lives. "Is it genes?" the cold, analytical mind ponders. It is kind of funny, yet it is tragic, and so it invites a response.
Yes, love makes life worth living. Not just relationships, but love, in its many varied forms. If you are reading this, I love you. To Ivy League scientists and their objects of study, I love you as well. You see, God is love, this is a simple truth found in scripture. Surround yourself in love at all times, and you will lead a life that is satisfying and resplendent in joy.