The transmission of social biases through instrumental learning

Although the detrimental consequences of prejudice are well documented, much less is known about how intergroup biases are acquired and spread. In this dissertation, I investigate how social biases can be formed and propagated between individuals by studying how impression formation interacts with social factors.
In Chapter 2, I investigated the mechanisms through which societal stereotypes are internalized as prejudice in the mind of the individual. In five experiments, participants acquired a preference for positively-stereotyped group members over negatively-stereotyped group members. findings show how stereotypes can affect impression formation without being endorsed.
In Chapter 3, I focused on the spread of social biases through observational learning. In six experiments, I found that observers of prejudiced intergroup interactions acquired similar group preferences as biased actors. These results reveal how social biases can be propagated between individuals by mere observation of others’ behavior.
Finally, in Chapter 4, I investigated how reinforcement learning mechanisms online can give rise to political polarization. In a series of studies, individuals posted political content to ostensible other users and received likes for their posts. Results showed that individuals learned to express extreme opinions online by pursuing social approval. This research suggests that social feedback processes may fuel political polarization in online environments.
Across three empirical chapters, I investigated how social biases can be propagated through features of social reinforcement learning. By focusing on the transmission of social biases through instrumental learning, my goal was to advance the scientific understanding of the origins of prejudice.