Much of the agile manifesto emphasized the importance of the human aspects of software development. In practice, however, even as agile methods have become ubiquitous, human aspects are often overlooked. For example, studies show customer collaboration is often avoided, and interaction designers seldom work together with programmers. New approaches such as DevOps too easily ignore the possible to better connect the people involved. Of course, human behaviour is challenging: complex, subtle, and only imperfectly understood. However, applying what we do know can lead to important opportunities. This presentation will review experience in studying the human side of agile methods, examining areas of success and failure, and identifying principles to support improvement.