[MUSIC] Hi, I'm Kayla de la Haye, and I'm a behavioral psychologist and social networks analyst in the Department of Preventive Medicine at the University of Southern California. The lecture today is going to focus on social networks and obesity. And social networks analysis as a component of system science methods. So, the first part of the lecture is asking what are social networks. So, social networks are social structures made up of social actors, so those might be people or even organizations. And then the web of relationships that surround these social actors. And these relationships could be very diverse. It might be individuals surrounded by their friends or family or co-workers or neighbors or even acquaintances. And some examples of social networks are things like, friendships among students in a school or university, advice giving among colleagues in an organization, social and sexual partnerships in a community, and even retweet networks in Twitter. And it also may be things like, alliances and collaboration networks among organizations or countries. So social network analysis and network science draws on a broad range of disciplines. So mathematics, graph theory, statistics, and computer science as well as social psychology and sociology. And this research in this area has given a rise to a number of social network theories. And these theories have come about in a large part because of people's dissatisfaction with theories that have focused very strongly on the individual. And a desire to understand and explain in mathematically model social phenomenon in a better way. And so, this body of social network research is applied in a huge range of disciplines from politics to organizational studies and studies of child development. And social network science is also very relevant to health behavior and public health issues. It's applied in a range of public health spaces largely to help us understand the impact of social networks and social relationships on people's health and health behaviors. But also to understand how people's health and their health behaviors impact the social networks that they belong to. So this is very much viewed as a systematic and interdependent relationship and it evolves together over time. In social network applications in public health have also focused on intervention design and so thinking about how we utilize social network patterns and structures. And to think about targeting key people in social networks for interventions. Or to think about how we harness, and activate, or maybe alter the social networks that people are embedded in. And to help promote healthy behaviors. And so, I've talked a lot about social networks being structures, and patterns of relationships. But it's also really critical to think about what these relationships entail and the functions of social networks and what they do and what flows through these networks. So social networks can be sources and conduits for the spread of information, new ideas or innovations, and they can also be conduits for the spread of things like contagious disease such as influenza or HIV. And social networks also influence our actions and our behaviors, meaning that we adjust and change our behaviors to reflect the characteristics of the people around us. And this occurs through a number of processes. Some of these are very unconscious processes, where we might unconsciously mimic or imitate the behaviors of people around us. But they also can be your very conscious processes where we learn behaviors from other people or we observe or socially compare ourselves to other people. And then adjust our behaviors to fit in with what's expected or normal in the social groups that we're embedded in. And social networks also function to provide us with social support. With aid, with resources, with things like getting a ride to go somewhere and resources that can have large impacts on our health. Social networks also provide us with social connections and opportunities for companionship and people to do activities with in leisure and daily activities with. And they also might include social rules and things like reciprocity, trust and rules about social exchanges. And they give rise to what's been called social capital that can have important impacts on people's behaviors and outcomes. And not all social network functions are necessarily positive or good outcomes. Social networks can also have a dark side. They might be critical or stigmatizing or socially exclude people. And they might also include relationships like aggression or bullying. I'll talk a little bit more about social support. This is a really function of social networks that has been found to have a very huge impact on health. So recent meta analysis by Holt Lunstad and colleagues in 2010 looked at a broad range of literature that examine the effects of our social relationships on our health outcomes. And they find that social connections are just as important, or a potentially even more important health factor, than some of these common health factors that we look at, like obesity, or smoking cessation, or physical activity. And different types of social support, so things like emotional support or tangible support. Where people provide us with information or resources or even money, have been found to have really important and different types of influences on our health behaviors, and health outcomes more generally.
