Theory of (bird) Mind: It take a thief to know a thief
My research has taken a curious turn lately. A couple of the recent undertakings, which themselves share few things in common, converge on the issue of Theory of Mind. Fortunately for me (and my tenure prospect) we have so far refreined ourselves from playing with non-human subjects. Nonetheless, the research on Scrub Jay’s food cashing behavior (read It take a thief to know a thief) seems to have some implications to what some of us is pursuing.
The central questions is the relationship between language and cognition, particularly the ability to reason counterfactually. Although the Sapir-Whorf hypothesis and the principle of linguistic relativity suggest that the ability should be at least mediated by language, if not fully supported by it. Jill de Villis has indeed argued that representing false beliefs — an indicator of Theory of Mind and a close cousin of counterfactual thinking — requires a particular syntactic structure that takes a full sentence as the complement ("he thinks/says that …."). This is logically necessary, she argues, because this is pretty much the only linguistic structure where the truth value of the main clause (whoe sentence) is not affected by the truth value of the embedded clause (the "…" part).
If this is true, then the scrub jays must have a recursive bird language.
It takes a thief to know a thief
Scientists say scrub jays are not stuck in the present
Mental time-travel, the ability to use memories of past experiences and plan for the future, has traditionally been considered a quality unique to humans. Now scientists at the University of Cambridge have identified the same ability in a bird - the Western scrub jay, [a US native] similar to the British jay.
In a paper published this week in Nature magazine they describe laboratory tests which show that scrub jays who have experience of stealing food from other birds? hidden caches seem to use this knowledge when hiding their own supplies.
"To our knowledge this is the first experimental demonstration that a non-human animal shows elements of mental time-travel," says Dr Nicky Clayton who conducted the research with her husband, Dr Nathan Emery.
Dr Clayton first observed the behaviour during lunch hours spent in the grounds of the University of California, Davis. She noticed that there was fierce competition between scrub jays for lunch scraps left behind by students and staff. In order to protect their hard-won scraps the birds would hide their winnings, Dr Clayton noticed that some scrub jays went even further - returning to re-bury the treasure when their rivals had left the scene.
The Nature paper was back to 2001. Just as interesting, the author puts a couple notes for prospective editors:
Notes for editors
1. Scrub jays are highly territorial - they hide food for future consumption, and rely on memory to recover these caches at a later date. But caching also has costs because these food stores can be found and taken by other birds. So in a competitive existence these birds need strategies to maximise their ability to recover the caches of other birds as well as their own, and counter strategies to prevent theft by pilfering competitors.
2. Nicky Clayton and Nathan Emery are a husband and wife research team. The publication of their Nature paper coincides with their joint birthday.
The latest development:
Science. 2004 Dec 10;306(5703):1903-7.
The mentality of crows: convergent evolution of intelligence in corvids and apes.
Emery NJ, Clayton NS.
Sub-Department of Animal Behaviour, University of Cambridge, CB3 8AA, UK. nje23@cam.ac.uk
Discussions of the evolution of intelligence have focused on monkeys and apes because of their close evolutionary relationship to humans. Other large-brained social animals, such as corvids, also understand their physical and social worlds. Here we review recent studies of tool manufacture, mental time travel, and social cognition in corvids, and suggest that complex cognition depends on a "tool kit" consisting of causal reasoning, flexibility, imagination, and prospection. Because corvids and apes share these cognitive tools, we argue that complex cognitive abilities evolved multiple times in distantly related species with vastly different brain structures in order to solve similar socioecological problems.
see my CiteULike notes