Arthur R. Jensen, whose suggestion a gap in IQ scores between black and white students might be rooted in genetic differences ignited controversy, has died. The death of Jensen at age 89 was confirmed by the University of California, Berkeley, where he was an emeritus professor in the Graduate School of Education. Jensen died Oct. 22 at his home in Kelseyville, Calif., The New York Times reported. Jensen was deeply involved in differential psychology and the age-old nature-nurture debate. In 1969, in an article published in The Harvard Educational Review, Jensen argued that general intelligence is largely genetically determined, with cultural forces -- nurture -- having only a small effect, a suggestion that ignited international controversy. Branded by some as a racist, Jensen was heckled at speaking engagements throughout his career and even received death threats. Some psychologists say they believe Jensen\'s work has been misunderstood. \"If you look at the Harvard Educational Review paper, he discusses race very little in that paper, but he did say that it\'s a possibility that there are genetic differences among racial groups,\" Douglas Detterman, a psychologist at Case Western Reserve University who edits the journal Intelligence, told the Times. \"And that was not a very popular idea when that paper came out.\"