Most (thought not all) people agree that human beings have rights. Almost all animal rights theories try to abstract why people think human beings have rights, and then argue that since animal species X has similar cognitive abilities as human beings and should be granted rights.
One issue that receives a lot of attention on both sides of the topic is the extent to which non-human animals are self-aware. Human beings not only think and act in the world, we can step back one level cognitively and think about thinking; we have conceptions of ourselves as self-aware actors who have a rich inner life that is every bit as important as the external actions we take.
There are a lot of different tests and experiments that animal rights activists cite to show that many if not most non-human animal species also have such levels of self-awareness, the problem being that the test becomes more abstract the further you get away from human beings. With primates, for example, there are a number of studies and research efforts on how different primate species conceive of themselves and other individuals, most of which have intriguing if inconclusive results. Once you get down to rats, mice and other animals, however, you find people arguing that because an animal can express pain or can make some simple differentiation between different states of affairs that it must be self-aware.
The problem being that a surprising new study of plants suggests that using the pain/state differentiation criteria, some plant species might be self-aware.
Japanese researchers, in a study published in Nature, reported on their work with lima beans. What they found was that when lima beans are being attacked by spider mites they release a distinctive chemical that performs two functions: it helps attract predators of spider mites and it alerts other plants nearby that spider mites are in the neighborhood. When lima beans are damaged by say a metal tool or by a clumsy animal like a cow, the beans gave off a different chemical which other lima bean plants ignore. The lima bean can distinguish between different types of predators, and can communicate to others of its species what sort of predator is in the neighborhood.
Dr. Junji Takabayashi, who led the research, speculates that “very probably, the spider mites inject some saliva leaves and this acts as an elicitor” for the specific anti-spider mite chemical.
Simple stimuli-response behavior? How different is this, in the end, from what goes on in very primitive animal species that many activists are more than willing to grant rights? After all if a lobster’s small repertoire of responses to danger can be considered evidence that it is self-aware in a way substantively close to human self-awareness, why not grant the painful cry of the lima beam similar status?
Source
How plants ‘shout attack!’. Jonathan Amos, The BBC, August 3, 2000.