Progress has been made in our understanding of the biological and psychological mechanisms involved in reporting pain, but there is limited research on the social influences on pain. Pain rarely occurs in isolation and the Social Communication Model of Pain emphasises the complexity of pain communication, and how social and contextual influences can have an impact on pain reporting. Over recent years, there has been an increase in the number of experimental and clinical studies focusing on how pain is reported when there is an observer present, but there have been inconsistent results. Furthermore, most studies do not control for sex differences, despite sex differences in pain being widely accepted and disseminated. This PhD thesis focused on the social and contextual influences on pain. Initially I 1) explored whether presence of someone else can have an impact on pain reporting, 2) considered whether the dyadic relationship can have an impact, and 3) whether there were any sex differences present. Previous research in the social influences on pain has considered sex differences, but not sex differences in the observer. Building on the results from Chapters 3, 4, and 5, the second part of this thesis focused on the characteristics of friendship, and whether specific aspects such as competitiveness play a role in pain. The first part of this thesis (Chapters 3, 4, and 5) adopted an experimental pain-induction approach, and recruited dyads along a continuum of closeness (strangers, opposite-sex friends, same-sex friends, and romantic partners). Overall, this series of studies highlighted that when an observer is present, pain threshold and tolerance increased. In addition, the nature of the dyadic relationships was found to impact on pain tolerance; pain is most tolerated when a friend is present, especially when the friend is the same-sex. Across all three experimental studies, men had a higher pain threshold and tolerance than women, which supports previous research investigating sex differences in pain. Based on these findings, the characteristics of friendship were explored further in Chapters 6 and 7. Two key components of friendship are competitiveness and cooperativeness, which were explored amongst same-sex and opposite-sex friends (Chapter 6), and same-sex and opposite-sex strangers (Chapter 7). Using a similar experimental pain-induction design as before, competitiveness and cooperativeness were manipulated using a virtual tennis game. Participants competed against one another in a singles match (competition) or together in a doubles tennis match against the games console (cooperation). For the same-sex and opposite-sex friends study, few differences were found. However, for the same-sex and opposite-sex strangers study, pain tolerance was higher for female participants with a male observer in the competitive condition. This highlights the importance of both dyadic relationships and context, in understanding responses to pain. The link between competitiveness and masculinity is highlighted in this study with women having biggest increase in pain tolerance, suggesting that the masculine gendered context resulted in women suppressing their pain. However, there is more research that needs to be conducted before a complete understanding can be gained. The significance of this work is that it contributes to our understanding about how and why other people can have an impact on the pain of others. Pain reporting is the initial stage required to alleviate the pain, and a greater understanding of how pain is reported to others can help researchers understand more about the social influences on pain. This work suggests that the communication of pain may depend on the nature of relationship with others, including health care professionals, as well as the impact of gender-related contextual factors. Future investigations need to expand this research theme to clinical acute and chronic pain settings, and explore variation in pain reporting within naturally competitive environments.