What are feelings for? Most nonscientists will find it a strange question. Feelings justify themselves. Emotions give meaning and depth to life. They exist without serving any other purposes. On the other hand, many evolutionary biologists acknowledge some emotions primarily for their survival function. For both animals and humans, fear motivates the avoidance of danger, love is necessary to care for the young, and anger prepares one to hold ground. But the fact that a behavior functions to serve survival need not mean that. Other scientists have regarded the same behavior as conditioning and learned responses. Certainly reflexes  and fixed action patterns can occur without feeling or conscious thought. A baby seagull pecks  at a red spot on the bill  of its parent. The seagull parent feeds its baby when pecked on the bill and the baby gets fed. The interaction need have no emotional content. At the same time, there is no reason why such actions cannot have emotional content. In mammals that have given birth including humans, milk is often released automatically when a new baby cries. This is not under intended control but it is reflex. Yet this does not mean that feeding a new baby is exclusively reflex and expresses no feeling like love. Humans have feelings about their behavior even if it is conditioned or reflexive. Yet since reflexes exist and conditioned behavior is widespread, measurable, and observable, most scientists try to explain animal behavior by using only these concepts. It is simpler. Preferring to explain behavior in ways that fit science's methods most easily, scientists have refused to consider any causes for animal behavior other than reflexive and conditioned ones. Scientific orthodoxy  holds that what cannot be readily measured or tested cannot exist, or is unworthy of serious attention. But emotional explanations for animal behavior need not be impossibly complex or unstable. They are just more difficult for the scientific method to check on in the usual ways, so cleverer and more skillful approaches are called for. Most branches of science are more willing to make successive evaluation of what may prove ultimately unknowable, rather than ignoring it altogether. To study animal emotions, scientists should   _  .
analyze human emotions distinguish what is emotional set up improved experiments learn from animal behaviorists