 26. Naturalizing the Self 571
lup, 1981), gorillas (Parker, 1994; Patterson 
& Cohn, 1994), dolphins (Reiss & Marino, 
2001), killer whales (Delfour & Marten, 
2001), Asian elephants (Plotnik, de Waal, 
& Reiss, 2006), magpies (Prior, Schwarz, 
& Güntürkün, 2008), and manta rays (Ari 
& D’Agostino 2016) have demonstrated the 
capacity for self-  recognition.
The other two cognitive-  behavioral 
markers—  imitation and role taking—  are 
present in humans by 2 years of age but ex -
tremely rare in other species. Nonetheless, 
they have been observed in chimps, orang -
utans, gorillas, and possibly monkeys, sug -
gesting that these animals have at least some 
capacity for imitation and role taking.
Emotional  Markers
Like human children, nonhuman primates 
exhibit behaviors that suggest the capacity 
to experience self-  conscious emotions and 
related social emotions, such as compassion 
and empathy. Much of this evidence, how -
ever, is anecdotal. In one incident, Supinah, 
an orangutan, was observed attempting the 
difficult task of hanging a hammock from 
two trees. After successfully hanging the 
hammock, Supinah “threw herself back in 
the hammock” and “hugged herself with 
both arms” in apparent pride (Hayes, 1951, 
p. 188). In the primate literature, research -
ers have described dominant, or alpha male, 
chimpanzees walking with a “cocky” gait, 
upright posture, and piloerected fur, sug -
gesting the possibility of a precursor to the 
pride display among these animals (de Waal, 
1989). However, more controlled studies are 
needed.
Evidence for empathy in primates is also 
mostly anecdotal. For example, it is not 
uncommon for a wounded chimp to be at -
tended to—fed, groomed, and protected— 
by other members of the social group; domi -
nant adult males even chase away playing 
infants or noisy group members to keep 
them from disturbing the injured chimp 
(Boesch, 1992). Warneken and Tomasello 
(2006) provided more direct support for em -
pathy and altruism in chimps. After observ -
ing an experimenter “drop” an object and 
act as if she could not reach it, chimps were 
found to help out by retrieving the object 
and giving it to the experimenter, suggest -ing that they understood the experimenter’s 
dilemma and empathized. However, in tasks 
where the experimenter’s goal was more 
difficult to understand (e.g., trying to get 
around physical obstacles), chimps failed to 
provide help, whereas children as young as 
18 months did. Similarly, in a study of 40 
chimps, Rosati, DiNicola, and Buckholz 
(2018) found evidence for empathy-  based 
helping behaviors in some contexts (handing 
an out-of-reach object to an experimenter) 
but not others (showing no preference for 
a plate that included snacks for the chimp 
and the experimenter vs. the chimp alone). 
Thus, like other aspects of human nature— 
personality, memory, attachment—  we share 
many capacities with our phylogenetic cous -
ins but differ in the complexity and frequen -
cy with which we display these capacities.
The findings of cross-  species research on 
the self have several implications. First, they 
illustrate the value of a comparative perspec -
tive in personality psychology. Comparative 
research helps identify which aspects of the 
self are uniquely human and which are com -
mon across species. Second, the finding that 
other species share certain aspects of the 
human self implies that self-  awareness and 
self- recognition may be evolved capacities. 
Any capacity that is common to several spe -
cies of primates is probably not crucially 
dependent on any species-  specific factors, 
such as culture or language. (Conversely, the 
fact that certain aspects of the self, such as 
the experience of guilt, seem to be unique to 
humans raises the question of whether these 
aspects are newly evolved differences, or the 
products of human culture.) Third, com -
parisons with other species reveal what our 
conscious mental life might have been like 
at an early period in our evolutionary his -
tory; that is, early humanoids may have had 
the same level of self-  awareness as chimps. 
A phylogenetic perspective suggests that the 
self may have evolved from the most basic 
form of self-  awareness (distinguishing self 
and nonself) to more complex forms of self- 
awareness seen in nonhuman primates (e.g., 
self- recognition) to the most complex forms 
of human self-  representations (e.g., identity).
Finally, the existence of cross-  species sim -
ilarities and differences suggests one route 
to understanding the neural bases of the 
self. Can we identify brain regions or neural 