We’re all embedded in vast social networks of friends, family, co-workers and more. Harvard professor Nicholas Christakis tracks how a wide variety of traits – from happiness to obesity – can spread from person to person, showing how your location in the network might impact your life in ways you don’t even know. youtu.be/2U-tOghblfE

Many people turn to networking when they’re looking for a job, but the best time to build your network is before you need something; and the best time to keep that network strong is always. But what is the best way to do that? Simply collecting business cards and attending events may expand your number of contacts, but does not increase the likelihood that those contacts will benefit you in the future. To reap the benefits of networking when you need them, you must know