[Note (14-Feb-2008): I received a number of comments on the following post. Within the comments, I speculated that the New Scientist article cited below might have confused seconds with milliseconds. One of the co-authors of the paper mentioned by New Scientist confirmed that the magazine had got it wrong, but that there should actually have been no units. This invalidates much of my original criticism of their experiment, although I remain sceptical. Please check out the comments for more details. The comments did not survive a relocation of this blog.]
New Scientist: Monkeys tune in to your way of thinking (subscribers only)
… Vittorio Gallese of the University of Parma, Italy, has found that macaques can predict the future actions of others, casting doubt on the long-held idea that monkeys cannot understand other beings as agents with their own perspectives and intentions.
Six macaque monkeys were shown a simple goal-related task - a woman reaching over a tall obstacle to pick up a toy resting on the other side. Once the monkeys had got used to this, the obstacle was removed so that the woman could simply reach out and pick up the toy.
The team found that when she did this, the monkeys showed a minimal amount of interest in her actions: each gazed at her face for an average of just 7 milliseconds. If, however, she continued to behave as if the obstacle were still in place and used the "reach-over" path to the toy, the monkeys showed more interest, gazing at her face for around 18 milliseconds on average (Current Biology, DOI: 10.1016/j.cub.2007.12.021).
Gallese concludes that the results show that monkeys recognise intention in goal-related tasks, and use that ability to predict how others will act. When no obstacle was in place but the woman still reached for the toy as if it were, she was acting in an unexpected manner, and Gallese says the monkeys spent longer gazing at her face because they were looking for clues to explain her behaviour.
Let's put these timings into perspective. The difference between 7 milliseconds and 18 milliseconds is just over 1/100th of a second. A typical television set displays pictures at 30 frames per second (i.e. each frame appears to last for 33 milliseconds—or about twice as long as these monkeys gawp in astonishment at the woman's unexpected behaviour). Blink, and you would literally miss it.
In what way can looking at something for 18 milliseconds be described as a gaze? Gallese seems to be reading an awful lot into such fleeting glances.