Complex sentence: Nikki R. Crick (February 6,1958-October 28,2012) was a psychologist and professor of child development and family studies known internationally for her research on relational forms of aggression.
Split into simpler sentences: Nikki R. Crick (February 6,1958-October 28,2012) was a psychologist and professor known for child development and family studies. She is also known internationally for her research on relational forms of aggression.