Donald Thomas Campbell was an American social scientist born in 1916. He completed his undergraduate education in psychology at UC Berkeley, where he graduated first in his class in 1939. After serving in the Navy during World War II, he earned his PhD from Berkeley in 1947 and taught at several universities. Campbell made significant contributions to research methodology and developed the concept of "evolutionary epistemology." He received numerous honors for his work, including election to the National Academy of Sciences.