Eating is related to emotional as well as physiologic needs. Sucking, which is the infant's means of gaining both food and emotional security, conditions the association of eating with well-being or with deprivation. If the child is breast-fed and has supportive body contact as well as good milk intake, if the child is allowed to suck for as long as he or she desires, and if both the child and mother enjoy the nursing experience and share their enjoyment, the child is more likely to thrive both physically and emotionally. On the other hand, if the mother is nervous and resents the child or cuts him her off from the milk supply before either the child's hunger or sucking need is satisfied, or handles the child hostilely during the feeding or props the baby with a bottle rather than holding the child, the child may develop physically but will begin to show signs of emotional disturbance at an early age. If, in addition, the infant is further abused by parental indifference or intolerance, he or she will carry scars of such emotional deprivation throughout life.

Eating habits are also conditioned by family and other psychosocial environments. If an individual's family eats large quantities of food, then he or she is inclined to eat large amounts. If an individual's family eats mainly vegetables, then he or she will be inclined to like vegetables. If mealtime is a happy and significant event, then the person will tend to think of eating in those terms. And if a family eats quickly, without caring what is being eaten and while fighting at the dinner table, then the person will most likely adopt the same eating pattern and be adversely affected by it. This conditioning to food can remain unchanged through a lifetime unless he individual is awakened to the fact of conditioning and to the possible need for altering his or her eating patterns in order to improve nutritional intake. Conditioning spills over into and is often reinforced by religious beliefs and other customs so that, for example, a Jew, whose religion forbids the eating of pork, might have guilt feelings if he or she ate pork. An older Roman Catholic might be conditioned to feel guilty if he or she eats meat on Friday, traditionally a fish day.