Oster discusses the impact of children on marital satisfaction, acknowledging the common belief that introducing kids into a relationship can lead to increased tension. Oster supports this notion by citing various studies that demonstrate a decline in marital happiness after having children. Drawing parallels to conflicts that arise when couples move in together, Oster humorously recounts a persistent disagreement with her husband, Jesse, over kitchen sponge etiquette.

She highlights the challenge of adjusting to significant changes in daily routines, which becomes more pronounced with the arrival of children. Oster addresses the common notion that children can “ruin” marriages, acknowledging the heightened stakes and exhaustion that accompany parenthood. She presents evidence from various studies, spanning back to 1970, indicating that marital satisfaction commonly declines after the birth of children, with a notable dip in the first year.

The unequal distribution of household chores emerges as a significant contributor to dissatisfaction, with women often shouldering a disproportionate burden even when both partners work full time. Oster notes that while there has been progress in achieving more equal sharing of chores, a gender gap still exists, affecting women’s happiness and creating tension in relationships. The author also highlights the decline in sexual activity after having children, attributing it to factors like time constraints, exhaustion, and the presence of children in the household.