Consciousness

and Lori Marino (2001) marked them with either
temporary black ink or just water on parts of their
body they could not see. Both spent much more
time twisting and turning in front of the mirror
when the ink was used, in ways that would help
them see the otherwise invisible marks.

Elephants are also highly intelligent, social ani-
mals with large brains, although radically differ-
ent from apes and humans in their lifestyle and
behaviour. Three Asian elephants were given
large mirrors and not only passed the mark test
but were found to go through the familiar stages
of mirror use, progressing from social responses
through physical inspections to testing the mirror with their own behaviour and
finally apparently recognising themselves (Plotnik, de Waal, and Reiss, 2006).

Remarkably, some corvids do the same (Prior et al., 2008). Famously intelligent
New Caledonian crows and jungle crows seem only to be able to use mirrors to
explore the environment (Medina, Taylor, Hunt, and Gray, 2011). But when five
European magpies were tested, they began by behaving as though another mag-
pie were behind the mirror. Some were quite aggressive but then progressed to
using the mirror in other ways, and three removed marks placed on their throats
by looking in the mirror. What makes this so remarkable is that corvids’ brains are
quite different from those of great apes or elephants. The last common ancestor
of mammals and birds was nearly 300 million years ago, and since then mammals
have developed their layered cortex while birds developed a cluster of forebrain
components. Bird brains are also tiny compared with ours, but their neurons are
about twice as densely packed as those of mammals, and are especially dense
in the forebrain (Olkowicz et al., 2016). Absolute brain size may also not be as
important as size relative to body weight. In all animals that have passed the MSR
test, the brain to body weight ratio is very high.

We still do not know for sure which species can and cannot recognise themselves
in a mirror, but the test does seem to reveal an evolutionary convergence of abil-
ities between radically different kinds of animals that are all sociable, intelligent,
and capable of insight and imitation.

So what does MSR tell us about consciousness? It does not necessarily follow
that because an animal can recognise its own body in a mirror, it has either self-
awareness or a concept of self. For example, an ape might work out the contin-
gencies between making movements and seeing effects in the mirror without
concluding that the arm in the mirror is its own. Or a magpie might conclude that
the mirror shows its own body without having any concept of itself as seen by
others, or self as an agent or experiencer.

There is lively debate over this issue. Gallup (1998) is convinced that chimpan-
zees have not only MSR but also a concept of self and self-awareness. He even
suggests that with this self-concept comes the beginnings of autobiographical
memory and awareness of a personal past and future. In Damasio’s (1999) terms
(Chapter 16), this would imply extended consciousness and an autobiographical
self as well as core consciousness.

‘Can animals

empathize? Yes.’

(Gallup, 1998)

Species Brain

Weight (g)

Body

Weight (kg)

%BrainWeight

×1,000

European Magpie 5.8 0.19 31

African Grey Parrot 9.18 0.40522.6

Pigeon 2.40.5 5

Human 1,350 65 21

Chimpanzee 440528

Gorilla 406207 2

Rhesus Monkey 68 6. 61

Asian Elephant7,500 4,700,00 01 .6

Bottlenose Dolphin1,600 1709

Cat 25.6 3. 38

FIGURE 10.10 • Encephalisation quotient (Cairo ̇,

2011, p. 6). Can we tell an

animal’s intelligence from

its brain size? Since brain

size generally increases with

body size methods have been

devised for comparing relative

brain size across species. The

EQ, developed for comparing

mammals, is a measure of

how far the brain weight of

a given species differs from

that expected for an animal

of its size. On this measure,

although we do not have the

largest brains in absolute terms,

humans score highest. But no

measure is perfect for assessing

intelligence: for example, a

thin and a fat person will have

significantly different EQs.

Even if we could accurately

compare intelligence across

(and between) species, would

this tell us anything about

consciousness?