Extraversion has two central characteristics: (1) interpersonalengagement, which consists of affiliation (enjoying and valuing close interpersonal bonds, being warm and affectionate) and agency (being socially dominant, enjoying leadership roles, being assertive, being exhibitionistic, and having a sense of potency in accomplishing goals) and (2) impulsivity, which emerges from the interaction of extraversion and a second, independent trait (constraint). Agency is a more general motivational disposition that includes dominance, ambition, mastery, efficacy, and achievement. Positive affect (a combination of positive feelings and (...) motivation) is closely associated with extraversion. Extraversion is accordingly based on positiveincentivemotivation. (shrink)

Eating behaviors evolve during the first years of life as biological and behavioral processes directed towards meeting requirements for health and growth. For the vast majority of human history, food scarcity has constituted a major threat to survival, and human eating behavior and child feeding practices have evolved in response to this threat. Because infants are born into a wide variety of cultures and cuisines, they come equipped as young omnivores with a set of behavioral predispositions that allow them to (...) learn to accept the foods made available to them. During historical conditions of scarcity, family life and resources were devoted to the procurement and preparation of foods, which are often low in energy, nutrients, and palatability. In sharp contrast, today in non-Third World countries children's eating habits develop under unprecedented conditions of dietary abundance, where palatable, inexpensive, ready-to-eat foods are readily available. (shrink)