Exploring the interface of physics and biology, our group seeks simple, unifying principles in the dynamics of living systems. In distinction to traditional biophysical approaches we work on a collective scale: analyzing the natural behavior of entire organisms, incorporating patterns of neural activity from across the brain and quantifying the patterns in complex experiences such as language. To make progress, we leverage close experimental collaborations to combine novel measurements of living systems in their natural sate with theoretical ideas drawn from statistical physics, information theory and dynamical systems. In the natural wiggling of the roundworm C. elegans we uncovered a low-dimensional but complete basis of worm shape (eigenworms) and we are exploiting this basis to understand generally how biological systems both move and think. In human neuroscience, we developed a computational approach based on the coupled neural dynamics of multiple brains engaged in natural, social interaction. In all of these efforts, we use the variation of biological systems under natural conditions to seek rather than impose a simple, mathematical understanding.