The ability to recognize oneself in a mirror is an exceedingly rare capacity in the animal kingdom. To date, only humans and great apes have shown convincing evidence of mirror self-recognition. Two dolphins were exposed to reflective surfaces, and both demonstrated responses consistent with the use of the mirror to investigate marked parts of the body. This ability to use a mirror to inspect parts of the body is a striking example of evolutionary convergence with great apes and humans.T he capacity for mirror self-recognition (MSR) has been found only in humans and great apes (1-8). In humans, MSR does not emerge reliably until 18-24 months of age (9) and marks the beginning of a developmental process of achieving increasingly abstract psychological levels of self-awareness, including introspection and mental state attribution (10, 11). The first evidence for MSR in a nonhuman species was experimentally demonstrated in the common chimpanzee (1), but numerous subsequent attempts showed no convincing evidence of self-recognition in a variety of other primates and nonprimates, including monkeys, lesser apes, and elephants (12-18). All of these species, including African gray parrots (19) demonstrate the ability to use a mirror to mediate or guide their behavior. A provocative debate continues to rage about whether self-recognition in great apes implies that they are also capable of more abstract levels of self-awareness (20). Therefore, research on self-recognition in other species will have profound implications for the idea that humans are the only species to conceive of their own identity.The apparent confinement of self-recognition to great apes and humans has stimulated scientific interest in the evolutionary significance of MSR based on common aspects of the social ecology, cognition, and neurobiology of these species (21-25). Dolphins have a high level of encephalization and behavioral and cognitive complexity (26-29), but previous attempts to demonstrate MSR in dolphins have been suggestive yet inconclusive because of difficulties in implementing adequate controls necessary to obtain robust evidence of MSR in an animal unable to display self-recognition by touching a marked part of the body with a hand (30,31).Conclusive evidence of self-recognition in a species as phylogenetically distant from primates as dolphins would play a pivotal role in determining whether this capacity is a byproduct of factors specific to great apes and humans or whether more general characteristics, such as a high level of encephalization, could help to explain the evolution of this capacity. General Methods and ProceduresThis study relies on sampling sufficient combinations of control and test situations to produce specificity effectively equivalent to hand use. We conducted a two-phase experiment to independently test whether two dolphins would use a mirror to view themselves after being marked, sham-marked, or not marked (untouched) in the presence or absence of reflective surfaces. During Phase 1, one subject was marked and s...

Considered an indicator of self-awareness, mirror self-recognition (MSR) has long seemed limited to humans and apes. In both phylogeny and human ontogeny, MSR is thought to correlate with higher forms of empathy and altruistic behavior. Apart from humans and apes, dolphins and elephants are also known for such capacities. After the recent discovery of MSR in dolphins (Tursiops truncatus), elephants thus were the next logical candidate species. We exposed three Asian elephants (Elephas maximus) to a large mirror to investigate their responses. Animals that possess MSR typically progress through four stages of behavior when facing a mirror: (i) social responses, (ii) physical inspection (e.g., looking behind the mirror), (iii) repetitive mirror-testing behavior, and (iv) realization of seeing themselves. Visible marks and invisible shammarks were applied to the elephants' heads to test whether they would pass the litmus ''mark test'' for MSR in which an individual spontaneously uses a mirror to touch an otherwise imperceptible mark on its own body. Here, we report a successful MSR elephant study and report striking parallels in the progression of responses to mirrors among apes, dolphins, and elephants. These parallels suggest convergent cognitive evolution most likely related to complex sociality and cooperation.cognition ͉ mirror self-recognition ͉ theory of mind ͉ intelligence ͉ empathy M irror self-recognition (MSR) is exceedingly rare in the animal kingdom (1). Attempts to demonstrate MSR outside of the Hominoidea (i.e., humans and apes) have thus far failed (2), with the notable exception of one report on dolphins (Tursiops truncatus) (3). Animals that demonstrate MSR typically go through four stages: (i) social response, (ii) physical mirror inspection (e.g., looking behind the mirror), (iii) repetitive mirror-testing behavior (i.e., the beginning of mirror understanding), and (iv) self-directed behavior (i.e., recognition of the mirror image as self) (3, 4). The final stage is verified if a subject passes the ''mark test'' by spontaneously using the mirror to touch an otherwise imperceptible mark on its own body (1). Application of the mark is recommended only if the preceding criteria have been met (5). Animals without MSR tend to remain at stages 1 and 2. Even if the degree to which the mirror image is confused with a stranger is debatable for some non-MSR species (6), these animals likely lack understanding of who is in the mirror.Gallup was the first to hypothesize about a phylogenetic connection between MSR and empathy (7), a connection supported by evidence for consolation behavior in apes but not monkeys (8, 9). A possible ontogenetic connection between MSR and empathy is reflected in the coemergence of MSR and ''sympathetic concern'' during child development (10, 11). Dolphins and elephants represent interesting additions to MSR tests because, like the hominoids (8, 12), they are highly empathic animals known for so-called ''targeted helping'' [i.e., helping that takes the specific needs of others ...

A group of eminent cetacean researchers respond to headlines charging that dolphins might be "flippin' idiots". They examine behavioural, anatomical and evolutionary data to conclude that the large brain of cetaceans evolved to support complex cognitive abilities.

Two female bottlenose dolphins (Tursiops truncatus) and their 2 male offspring were presented with an underwater keyboard to observe how the dolphins would use such a system to obtain specific objects and activities. When a dolphin pressed visual forms on the keyboard, whistles were generated underwater, and the dolphin was given a specific object or activity. Both vocal and nonvocal behaviors were recorded. Only the males used the keyboard. In the 1st year spontaneous vocal mimicry and productive use of facsimiles of the computer-generated whistles were recorded. In the 2nd year productive use increased significantly over mimicry, and apparent combinations of discreet whistle facsimiles in behaviorally appropriate contexts were observed. The patterns of vocal mimicry and production suggest a new model for analyzing dolphin vocalizations and vocal development with respect to signal structure and organization.