Maslow's Hierarchy of Needs. Definition. Maslow's hierarchy of needs is a theory of motivation and personality developed by the psychologist Abraham H. Maslow (1908â1970). Maslow's hierarchy explains human behavior in terms of basic requirements for survival and growth.
When you use ice to cool the ingredients for ice cream, the energy is absorbed from the ingredients and from the outside environment (like your hands, if you are holding the baggie of ice!).
The answer, at least a partial one: eggs. Eggs, specifically egg yolks, play several roles in homemade ice cream. You can make tasty ice cream without them, but there's a reason that almost every recipe published in the last 50 years calls for them. Here's why: After water, egg yolks are mostly fat and protein.