Nielsen Holdings, a global performance management company that provides a comprehensive understanding of what consumers watch and buy, has elected James Attwood as non-executive chairman of its board of directors, effective as of Jan. 1.  Attwood previously served as the board's lead independent director. 

Attwood succeeds David Calhoun who served as executive chairman of the board since 2014. Calhoun will continue to serve as a director on Nielsen's board.