While differences in how men and women speak in parliament are well established, we still lack evidence encompassing a longer time span. Using Finnish parliamentary speech data from 1948 to 2018—a period spanning from token female presence to near-parity—we find that while women have always spoken differently than men, the differences widen as women’s share of seats surpasses roughly 10–20% in the 1960s. Crucially, women already serving in parliament at that point also shift toward topics more closely aligned with “women’s issues”, suggesting the change reflects a collective contextual shift rather than the arrival of new cohorts. Moreover, tenure length is not correlated with how women speak, further indicating that changes in women’s behavior relate more to contextual factors than to individual career trajectories.