Humans are prodigious social learners, and social learning is the engine of cumulative culture. In online social networks, algorithms mediate how we learn from others, with implications for cultural evolution in the digital age. In this talk, I will explore how social learning unfolds in online social networks, with a focus on learning and sharing moral expressions. I’ll present empirical work suggesting that algorithmic amplification exploits social learning biases that evolved to promote cooperation, resulting in distorted learning about collective moral beliefs. Finally, I’ll speculate on how algorithm-mediated social learning shapes the cultural evolution of morality.