Instinct. Poster of the 1999 movie and cover of the 1992 book, Ishmael
VS3
Ishmael
Daniel Quinn, 1992
movie vs book
Jon Turteltaub, 1999

In a high-security facility for the criminally insane, the disturbed anthropologist Ethan Powell is scheduled for evaluation by a talented young psychiatrist named Theo Caulder. Fueled by his ambition and an insatiable thirst for the truth, Caulder will ultimately endanger everything, including his own life, in a courageous effort to comprehend the perplexing behaviors of this lunatic.