The early roots of modern thinking about intelligence perhaps extend back as far as the publication of Charles Darwin’s (1859) Origin of Species. This volume had a profound impact on many fields of scientific endeavor. One of the lines of inquiry was the investigation of human intelligence. The book argued that the capabilities of humans are in some ways continuous with, rather than totally distinct from, those of lower animals. Hence, they could be understood through scientific investigations much like those directed at lower animals. Investigators of intelligence picked up on some of Darwin’s ideas. As you read this chapter, consider how Darwin’s ideas have permeated thinking throughout the history of attempts to understand intelligence (Sternberg, 1985b, 1986, 1990). What are some of these attempts?