This study examined whether social bias manipulation can influence how naïve multiage listeners evaluate second language (L2) speech. Sixty native English-speaking listeners (Montreal residents) rated audio recordings of 40 Quebec French speakers of L2 English for five dimensions of oral performance (accentedness, comprehensibility, segmental accuracy, intonation, flow) using 1,000-point continuous scales. Immediately before rating, 20 listeners heard critical comments about Quebec French speakers' English language skills, while 20 heard positive comments. Twenty listeners (baseline group) received no manipulation. Compared to baseline listeners, positively oriented listeners (younger and older) rated four of five dimensions more favorably. However, listeners' behavior diverged under negative bias. Compared to age-matched baseline listeners, younger listeners upgraded speakers while older listeners downgraded speakers for all targeted measures. Findings cast doubt on the relative stability of L2 speech ratings and point to the importance of social context and generational differences in untrained rater assessments of L2 speaking performance.