“One such evolutionary system, or ridge, encompasses panhuman emotional faculties, or affective "programs." These include the basic, or primary, emotions that Darwin first identified: surprise, fear, anger, joy, sadness, disgust, and perhaps contempt. Certain reactions characteristic of the neurophysiology of surprise and fear are already evident in reptiles, and the other primary emotions are at least apparent in monkeys and apes. Then there are the secondary, mostly "social" emotions, such as anxiety, grief, guilt, pride, vengeance, and love. These may be unique to humans-hence, at the lower level in our evolutionary mountain landscape and somewhat more liable to cultural manipulation and variation than the primary, "Darwinian" emotions. Thus, only humans seek revenge or redemption across lifetimes and generations, whatever the cost, although the nature of the deeds that trigger insult or remorse may vary considerably across societies, and the means to counter them may range even wider.”

Introduction: an evolutionary riddle, p. 11
In Gods We Trust: The Evolutionary Landscape of Religion (2002)