The influence of electronic word of mouth (eWOM) on consumers’ purchase intentions has long been known. However, the emergence of social media has brought a new perspective to eWOM through enabling users to communicate with their existing networks on the Internet. On social media, conversely to the other online platforms, users are able to exchange their opinions and experiences about products or services with familiar people, which refers to people who they already know such as friends and acquaintances. This new way of eWOM has the potential for greater impact on consumers. Therefore, the aim of this research is to examine the influence of eWOM in social media on consumers’ purchase intentions. To do so, the research in this thesis involved two major phases. In the first phase, in order to explore the determinants of eWOM information on social media which influences consumers’ purchase intentions, a theoretical model was developed based on the integration of Information Adoption Model (IAM) and related components of Theory of Reasoned Action (TRA). The new model, which is named as Information Acceptance Model (IACM), was validated through structural equation modelling (SEM) based on surveys of 384 social media users in the UK. The results have highlighted that quality, credibility, usefulness and adoption of information, needs of information and attitude towards information are the key factors for eWOM in social media which influence consumers’ purchase intentions. Furthermore, to provide better understanding of the influence of eWOM on social media, the second phase of this research was designed as a comparative study. To explore whether the eWOM between familiar people on social media or the eWOM between anonymous people on other online platforms was more influential on consumers’ purchase intentions, the data collected through survey was reanalysed with a different perspective; and a comparison was conducted based on multiple regression analysis. The results have revealed significant differences and found anonymous reviews to be more influential on consumers’ purchase intentions than friends’ recommendations on social media. However, since these results were contrary to expectations, 10 in-depth interviews were also administered to enlighten the insightful results found through the survey. The interview findings uncovered the survey results. Information quantity, information readiness, detailed information, and dedicated information were discovered as the factors which make online reviews superior than friends’ recommendations in terms of the influence of eWOM. This research contributes to theoretical implications through its validated model and found key dimensions. The research model, IACM, brings a new approach to information adoption by extending IAM and provides new insights to researchers who study Information Systems (IS). In addition, the model highlights the information adoption process as an antecedent of behavioural intention, which is a very important finding for the related literature. Future studies can build new models through considering this relationship between information adoption process and behavioural intention. Moreover, the second phase of this research provides new constructs for future studies through its qualitative findings. The findings reached through in-depth interviews, which explain why consumers prefer anonymous online reviews, can either be tested as components of new theories and models or they can be tested as inclusion of existing theories and models. Both types have potential to provide valuable results for the literature. On the other hand, in terms of practicality, this research provides marketers with a frame of reference to understand the influence of eWOM in social media on consumers’ purchase intentions. Both the contextual and the comparative studies in this research offer valuable insights for marketers; marketers thus can develop better strategies for marketing on social media.

This study examined factors important in determining the acceptance of racially charged humor. It utilized a 2 x 3 design in which race of joke teller and group targeted by the jokes were manipulated. It measured people’s level of acceptance regarding the jokes and recorded participants’ behaviors. This study found that under the conditions in which comedians derogated their in-group, White participants demonstrated higher levels of acceptance and a greater likelihood to perform the jokes. This pattern was especially true when the comedian was Black.