Der durchschnittliche Intelligenzquotient in einer Ehe beträgt immer exakt 100

The expression “Der durchschnittliche Intelligenzquotient in einer Ehe beträgt immer exakt 100” is Frieder’s mock mathematical theorem: whatever the spouses’ individual intelligence, their average supposedly comes to exactly 100. The narrator recalls the line while explaining both his contempt for his mother’s boyfriend and the circumstances that led him to move in with Frieder. Its neat arithmetic makes the joke memorable, but its target is not simply stupidity: it compresses the narrator’s sweeping, bitter impression of how intelligence and marriage are distributed around him.

The theorem and its comic logic

The narrator introduces the saying through Frieder’s explanation of mathematical propositions. A proposition, as the narrator recounts it, is a claim that has effectively been proved because it rests on axioms: rules so self-evident they cannot be further divided, “like an atom.” The account then wanders through Otto Hahn, the splitting of the atomic nucleus, and a commemorative five-mark coin before arriving at Frieder’s own theorem. The detour gives the joke a mock-scientific frame, setting an apparently rigorous mathematical law against a social observation that is anything but a proof.

The sentence’s exactness is part of the humor. It does not say that spouses are equally intelligent, only that their average is always precisely 100. Frieder’s formulation turns marriage into a calculation with a guaranteed result, a tidy rule that seems to account for even the most uneven pairings. The joke’s authority comes from its borrowed form—axiom, proposition, numerical conclusion—while its wit comes from treating a messy human relationship as if it could be settled by arithmetic.

The narrator’s family context

The narrator recalls the theorem amid his account of his mother’s boyfriend, whom he privately calls F2M2. Moving in with Frieder would let him escape the boyfriend’s demands to help pave the driveway, paint the facade, and nail ugly boards over the ceilings, as well as his constant complaints. The boyfriend mocked the narrator’s silence as snobbery, while reacting jealously when the narrator’s mother spoke with him for more than five minutes. He could then refuse to speak to her for days, drink six or eight beers, and eventually explode.

The narrator contrasts his mother’s intelligence with her boyfriend’s and generalizes from the parents of his friends: in his view, fathers were often much less intelligent than mothers, even when the fathers were engineers and the mothers were homemakers. He describes the kindest and cleverest women as having the stupidest men for husbands, then admits he cannot imagine what women see in such men; perhaps they earn a great deal, or possess other qualities he would rather not picture. Frieder’s theorem gives this frustrated judgment a compact, comic form. It should be read as the narrator’s caustic perspective, not as a claim independently established by the story.

From joke to shared household

The theorem appears beside a consequential decision. The narrator could move out without a major confrontation at home, because leaving would serve what he considers a good purpose: helping prevent Frieder from killing himself. He would not even have to pay rent. The arrangement carried a cost, however. As Vera pointed out, he might no longer feel able to go out at night or stay overnight with her, for fear of returning to find Frieder dead.

The narrator then considers whether he should not move in alone. If two people shared responsibility for keeping watch over Frieder, the burden would be less concentrated. Vera agreed to move in too. In the new household, the friends gathered around the kitchen table for their first evening meal, eating spaghetti while the only cassette they had unpacked played too loudly for conversation. This scene gives the theorem a setting beyond the narrator’s old home: the Auerhaus becomes a chosen household shaped by shared meals and attention to a vulnerable friend.

Marriage, care, and the limits of the joke

The saying reduces marriage to an average, but the surrounding narrative places it beside forms of care that cannot be reduced to a numerical rule. The narrator describes life in the shared house as full of conversation at breakfast, lunch, and dinner; all that talking, he says, meant keeping watch over someone who had once tried to kill himself. He still could not understand why someone would want to die—or how someone could actually attempt it—even while acknowledging that he understood it, in some sense.

Later, on December 24, the narrator explains that “home” changes meaning according to whom the residents are addressing. To outsiders, home means family; to those who belong to the Auerhaus, home means the Auerhaus. Returning to his family’s home, he finds that his sisters now have separate rooms and that one has inherited his portable television. These details place his departure from the old household alongside the formation of a new one. Against that movement, Frieder’s theorem remains a sharp joke about conventional marriage, while the story’s fuller account of home rests on who shares daily life and who takes responsibility for whom.