We found that over 3/4 of textbooks contained inaccurate statements.

From What Do Undergraduates Learn About Human Intelligence? An Analysis of Introductory Psychology Textbooks by Russell Warne, Mayson C. Astle, and Jessica C. Hill.  From the Abstract:

SCIENTIFIC Human intelligence is an important concept in psychology because it provides insights into many areas, including neurology, sociology, and health. Additionally, IQ scores can predict life outcomes in health, education, work, and socioeconomic status. Yet, most students of psychology do not have an opportunity to take a class on intelligence. To learn what psychology students typically learn about intelligence, we analyzed 29 textbooks for introductory psychology courses. We found that over 3/4 of textbooks contained inaccurate statements. The five most commonly taught topics were IQ (93.1% of books), Gardner’s multiple intelligences (93.1%), Spearman’s g (93.1%), Sternberg’s triarchic theory (89.7%), and how intelligence is measured (82.8%). We learned that most introductory psychology students are exposed to some inaccurate information about intelligence and may have the mistaken impression that nonmainstream theories (e.g., Sternberg’s or Gardner’s theories) are as empirically supported mainstream theories (such as Spearman’s g).