Excerpt from Animal Wise by Virginia Morell, plus links to reviews, author biography & more

It's probably best at this point to explain what I mean by thinking. First, it is an activity that takes place in a physical place, the brain. And second, to borrow from Richard Dawkins and Steven Pinker, the ultimate goal of thinking is to help ensure that the individual with the brain successfully reproduces, thereby making as many copies of the genes that created that brain as possible. What does an animal need to do in order to replicate? It needs to eat, so it must be able to find food. It needs some type of territory or home, so it must be able to find its way through the forest, waters, deserts, or skies, while avoiding hazards. Often an animal will have to elude predators, defend its home turf, or compete with others for a mate. And many animals must raise their young after they are hatched or born.

Animals must learn how to do many of these tasks, and this learning requires them to have memories and the ability to respond to new experiences and new information. The main purpose of learning and memories, and of cognition overall, is to reduce the uncertainties of life and to help an animal predict what may happen in the future.

Thinking in its simplest form may be something like information processing, as scientists such as Alan Turing, one of the key thinkers in the cognitive revolution, suggested in 1950. A brain takes in information via the senses— eyes, tongue, ears, skin, feather, scales, electrically sensitive whiskers, and so on—processes it, and produces a decision in the form of an action or behavior. The action, of course, leads to more information and to another behavior, so that a loop is created between senses, thoughts, and behaviors. Or, as a pair of biologists wrote, thinking "tempers the raw sensory information and prepares new electrical signals to further influence thought and behavior."

Often simple cognition is compared to the set of instructions that directs a computer as it processes data. Of course, that is only a metaphor for how a mind works. In most organisms, the instruction set is much more complicated. Learning, memory, hormones, emotions, gender, age, personality, and social factors—all the messiness of biology—come into play, too.

In human psychology, there's no longer a question about whether cognition operates separately from the emotions. It doesn't. There aren't separate pathways in the brain for thinking and for emotional feelings; they work together on a single track. The same is probably true for all vertebrates, possibly even some invertebrates—even though animals' emotional states are seldom studied. We know less about the emotional side of animal cognition than any other aspect. Comparative psychologists and cognitive ethologists don't deny that animals have emotions, but, as Frans de Waal has pointed out, they have not discovered how to study them.

Many researchers shy from the problem of animal emotions because they worry that such "inner states" cannot be studied—basically, the same argument behaviorists once used as the reason not to study cognition. I've also heard it argued that animal emotions are likely very simple and/or vastly different, even "alien," from those of humans (as if species other than us came from another planet). There is simply no evidence to back up such statements. Because evolution is conservative (for instance, human brains and those of all vertebrates, including fish and amphibians, use the same set of chemicals to transmit signals), it's more likely that many of our emotions are similar to those of other animals, as de Waal notes. Why, after all, reinvent sensations, such as fear, pain, or love, and the internal states or mental representations that accompany these? Emotions most likely help animals to survive and reproduce.

When I use the term thinking, I'm not implying that animals have language, because thinking does not require language. Thoughts can come as vivid mental images. For instance, the poetry of Samuel Taylor Coleridge often appeared to him in a visual way, and Albert Einstein wrote that his insights typically came as a result of picturing himself doing something like riding a beam of light. Scientists don't know how thoughts are represented in the minds of animals, but some speculate that other animals also think graphically, perhaps in pictures, possibly even animation.

Excerpted from Animal Wise by Virginia Morell. Copyright © 2013 by Virginia Morell. Excerpted by permission of Crown. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.