Mirror neurons have received quite a bit of attention since they were discovered in the 1990s. First found in macaques, these are nerve cells which fire both when the animal moves and when it sees another individual move in a similar way. These cells and their functioning are obviously fascinating because they suggest that the brain relates its own actions with those of others. But Antonio Damasio and Kaspar Meyer (2008) warn that perhaps the name was too evocative for the finding's own good. It seems to have tempted people into thinking of these neurons as tiny, miraculous mirrors that allow us to understand each other, diverting attention from the search for how they (p. 167). What Damasio and Meyer appear to be cautioning about here are the dangers of metaphorical thinking. There seems to be a lot of that going around lately. science writer Natalie Angier (2008) has an essay on what she terms biobigotry, something she freely admits being prey to. She describes the loathing she felt when she looked out to see cowbirds at her bird feeder and thought: Hey, you parasites, get your beaks off seed (p. D1). These freeloaders were taking food away from hard-working birds cardinals and woodpeckers. Angier confesses that she is using metaphorical language to make very human value judgments about other species, a form of anthropomorphism, something many biologists try to avoid. Angier's immediate and visceral response to cowbirds shows how difficult this is to do. We are metaphorical creatures; we think in comparisons, and we just can't seem to stop ourselves. Before I get more deeply into metaphors, I should mention other types of comparisons, namely similes and analogies. Like a metaphor, a simile is a literary device, a figure of speech. difference between them is that a simile uses like or as, while a metaphor doesn't. When I took literature, where I originally learned all this, I saw the difference as merely nitpicking; adding a little word didn't seem to make much difference. However, this simply shows literary naivete. My love is a rose has a lot less emotional power than my love is a rose, just as saying that a neuron is a mirror doesn't carry the weight of saying that a neuron is a mirror. As for an analogy, it is even more direct and less dramatic; it refers to cases where the comparison is between two things that are more fundamentally similar, such as referring to both pollen and sperm as male. Over the past 30 years or so, literary theorists and linguists have significantly rethought the importance of metaphors (Lakoff & Johnson, 1980). They used to be considered literary figures of speech and mainly in the realm of poetry and are now seen as fundamental to the way the human mind works. We can only learn about new things we encounter by comparing them to what we already know. Cowbirds deposit their eggs into the nests of other bird species which then raise the freeloaders, so just a tapeworm, the quintessential parasite, a drains food away from its host species. Freeloader makes it very clear to one who hasn't encountered cowbirds before, what to think of them: Cowbirds are obviously not good avian citizens. This highlights that there are value judgments associated with metaphors used in describing animals, a topic that has received attention from conservation psychologists, people who study the relationship between human emotional responses to organisms and their attitudes to environmental issues. Interaction View To appreciate what's going on in metaphorical language, it's helpful to examine the work of Max Black, a philosopher who developed the interaction view of metaphor in the 1950s. In the metaphor The is a freeloader, cowbird is the principal subject and freeloader the subordinate subject, according to Black's (1954) analysis. He argues that something is learned about the principal subject by comparing it to the subordinate one. …