Humans, chimpanzees, elephants, magpies and bottle-nosed dolphins can recognise themselves in a mirror, according to scientific reports, although as any human older than 50 knows, that first glance in the morning may yield ambiguous results.
Not to worry. Scientists are talking about specieswide abilities, not the fact that one's father or mother makes unpredictable appearances in the looking glass.
Mirror self-recognition, at least after noon, is often taken as a measure of a kind of intelligence and self-awareness, although not all scientists agree. And researchers have wondered not only about which species display this ability, but about when it emerges during early development.
Children start showing signs of self-recognition at about 12 months at the earliest and chimpanzees at two years old. But dolphins, researchers reported yesterday, start mugging for the mirror as early as seven months, earlier than humans.
Dr Diana Reiss, a psychologist at Hunter College, and Dr Rachel Morrison, then a graduate student working with Dr Reiss, studied two young dolphins over three years at the National Aquarium in Baltimore.
Dr Reiss first reported self-recognition in dolphins in 2001 with Dr Lori Marino, now head of the Kimmela Centre for Animal Advocacy. She and Dr Morrison, now an assistant professor in the psychology department at the University of North Carolina Pembroke, collaborated on the study and published their findings in the journal Plos One.
Dr Reiss said the timing of the emergence of self-recognition is significant because in human children, the ability has been tied to other milestones of physical and social development. Since dolphins develop earlier than humans in those areas, the researchers predicted that dolphins should show self-awareness earlier.
Seven months was when Bayley, a female dolphin, started showing self-directed behaviour, such as twirling and taking unusual poses.
Dr Reiss said dolphins "may put their eye right up against the mirror and look in silence". "They may look at the insides of their mouths and wiggle their tongues," she added. Foster, the male dolphin, was almost 14 months when the study started. It had a particular fondness for turning upside down and blowing bubbles in front of the one-way mirror in the aquarium wall through which the researchers observed and recorded what the dolphins were doing.