He is widely recognized for his significant contributions to the theories of protein folding, glasses, and gene networks.

After a brief postdoctoral research at Massachusetts Institute of Technology with John Deutch,[1] in the fall of 1976 he became an assistant professor at the chemistry department of Harvard University at the age of 23.

In 1980 he moved to the University of Illinois, eventually becoming the Center for Advanced Study Professor of Chemistry, Physics and Biophysics.

In 2000 he moved to the department of chemistry and biochemistry at the University of California, San Diego, as the Francis Crick Chair in the Physical Sciences.

In addition to continuing his work on many body chemical physics, protein folding and structure prediction, he studied stochastic aspects of cell biology.