Cat's Cradle is laced with irony and parody, but it is necessary to recognize the underlying implications of Vonnegut's humor. Although Vonnegut clearly intends for his readers to laugh while reading his book, Cat's Cradle is not merely a playful frolic through human foibles. Vonnegut employs humor as a means to make his reader assume a critical stance toward the "sacred cows" of their culture, of which science, religion, nation, and family are only a few. Underlying Vonnegut's playful humor is a sobering exploration of the dangers inherent in the combination of human stupidity and indifference with mankind's technological capacity for mass destruction.

The twentieth century added an ever-increasing pace of scientific advancement and industrialization to a pre-existing cauldron of religious, class, and international conflict. Although industrialization and scientific advancement offered millions of people a better standard of living, they also produced or exacerbated human suffering on many levels. The same scientific community that discovered antibiotics also produced the atomic bomb, nerve gas, automatic firearms, and a host of other efficient means to kill and maim human beings. The same process of industrialization that produced cheaper, standardized material goods came hand in hand with abusive labor practices and unsafe working conditions.

Vonnegut offers his readers a puzzling, disturbing portrait of "innocence" in Felix Hoenikker, a Nobel-prize-winning physicist, who approaches all of his research as a child would an amusing game. Felix lacks the malicious intent we associate with people we term "evil." He is as interested in researching the atomic bomb as he is in researching the behavior of turtles. He cares little for money, fame, or prestige, but he also cares little for other people, even his family; nor does he care for the implications his research could have for humanity. This seemingly harmless man helps build the atomic bomb and later produces ice-nine, an isotope of water that is solid at room temperature. By the end of Cat's Cradle, this second invention is responsible for the death of almost every living thing on earth.

Felix's neglected children also seem fairly harmless at first. At heart, Newt, Angela, and Frank simply want to be happy. However, their seemingly innocuous attempts to gain an impossible happiness leads to the destruction of life on earth. In this way, the Hoenikker children come to represent the people of the world; the search for happiness is perhaps the most universal of human endeavors and a noble goal. But, Vonnegut portrays this very human effort as being neither as simple, nor as simplistically moral, as it is generally perceived to be. Like their father, the Hoenikkers lack the malicious intent usually associated with people termed as "evil." Instead, they are careless, sometimes indifferent, often stupid, and ultimately caught up in their own lives. In Cat's Cradle, Vonnegut demonstrates that these traits—none of them evil—combined with man's technological power are enough to destroy the world.

Recorded history is replete with examples of violent religious, ethnic, and international conflict. None of this changed with the twentieth century. Nevertheless, many people in the twentieth century took the egotistical position that humanity had reached a new pinnacle of maturity. Science became a revered institution of truth and knowledge, and few people seriously questioned whether the truth and knowledge of modern science were necessarily beneficial. Cat's Cradle ridicules this hubris by emphasizing that sheer human stupidity is not only alive and well in the twentieth century but armed to the teeth.