Download Spontaneous Imitation in Animals and Humans

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Chapter 11 · Correspondence Relations
Of course, 4-month-old infants already have a considerable history of interaction with their
parents, and the observed tongue protrusion may simply be attributable to social conditioning. That
is, parents and other people may have smiled and laughed when the infant imitated their responses.
Presumably, these social consequences strengthen imitation by the child. Another possibility is that
primate infants make a lot of mouth-opening and tongue-protruding responses, especially when they
are aroused by some surprising event such as an adult face. In this case, the infant’s tongue protrusions merely coincide with that of the adult model and are not true imitations. Although social
conditioning and arousal are plausible, research with infants and animals is providing evidence for
innate or spontaneous imitation. Furthermore, specialized neurons in the brains of primates have
been discovered that may allow for early innate imitation by newborns, and more complex forms
of imitation and observational learning (see “New Directions: Behavioral Neuroscience, Mirror
Neurons, and Imitation” later in this chapter).
Spontaneous Imitation in Animals and Humans
Innate or spontaneous imitation, if real, is based on evolution and natural selection (a characteristic
of the species) rather than experiences and contingencies during the lifetime of the individual. That
is, imitation of others may be an important form of adaptive (functional) behavior (Davis, 1973;
Hutchinson, 1981; Millard, 1979; Porter, 1910; Thorpe, 1963). This behavior may range from a few
instinctive actions to a more generalized set of responses, depending on the species. In addition,
imitation may occur only when the model is present, or it may be delayed for some time after the
model has been removed. Such delayed imitation is often regarded as a more complex form, since
it involves “remembering” the modeled stimulus, rather than direct stimulus control (see Courage &
Howe, 2002, pp. 257–259, on cognitive development and delayed imitation; also see Chapter 8 of
this book for a behavior analysis of remembering and forgetting that does not rely on concepts of
memory and cognition).
There are ethological reports of imitation by animals and birds (e.g., Alcock, 1969; Fisher &
Hinde, 1949; Kawai, 1965). Fisher and Hinde (1949) described how birds in a southern English
village obtained milk by spearing the foil tops of bottles left on doorsteps. Eventually, this behavior
spread to several species of birds throughout England, Wales, Scotland, and Ireland. It stretches the
imagination to suppose that so many birds learned the same response on their own. One conclusion
is that the behavior was acquired and transmitted through observation and imitation (see Dawson &
Foss, 1965, for imitation of removal of container caps by budgerigars; see also Byrne, 2003, for a
discussion of ethological observations in the great apes).
Japanese macaque monkeys also seem to pass on novel behavior by observational learning.
A report by Kawai (1965) describes the social transmission of an innovative method of feeding.
The researchers spread grains of wheat on a sandy beach where the troop often visited. Each
monkey picked the grains from the sand and ate them one at a time. Then a young monkey
began to separate the sand from the wheat more efficiently by tossing a handful of mixture into
the water (see Figure 11.2). When this happened, the sand sank to the bottom and the wheat
floated to the top. Using this technique, the monkey obtained more wheat with less effort. Other
members of the troop observed this behavior and were soon imitating this new method of
feeding. Kawai indicated that observational learning transmitted many other novel behaviors,
including washing the sand off sweet potatoes and swimming in the ocean (see Ball, 1938, and
Breuggeman, 1973, for a discussion of imitation by rhesus monkeys; see Bering, Bjorklund, &
Ragan, 2000, for an account of delayed imitation by rhesus monkeys and orangutans; see also
Custance, Whiten, Sambrook, & Galdikas, 2001, for a report of failure to observe imitation in the
orangutan).
Imitation in the Laboratory
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Although it seems likely that
some birds, monkeys, and a few other
species, such as African gray parrots
(Moore, 1992), dolphins (Tayler &
Saayman, 1973), infant rhesus
macaques (Ferrari, Visalberghi,
Pauker, Fogassi, Ruggiero, & Suomi,
2006), and mongooses (Muller &
Cant, 2010) can imitate the novel
responses of a model, these naturalistic studies are not sufficient to
establish spontaneous imitation or to
rule out alternative processes such as
social facilitation (Zajonc, 1965),
stimulus enhancement, or copying FIG. 11.2 A Japanese macaque monkey is shown washing
grain to eat. Monkeys were found to learn this behavior by
(Galef, 1988, pp. 15–16; Galef, 1990; observation of other monkeys in the troop. Photograph by
Miklosi, 2007; see Zentall, 2006, for Heather Angel of Natural Visions is published with permission.
a review; see also Miller, RayburnReeves, & Zentall, 2009, and Zentall,
2011, for a description of experimental control procedures to establish true imitation). Social animals
have many experiences that may contribute to doing what others do. Therefore, it is not possible to be
sure that the imitation was spontaneous (based on species history) rather than acquired (based on social
learning). Only laboratory experiments can distinguish between acquired and spontaneous imitation.
IMITATION IN THE LABORATORY
Thorndike (1911) conducted the earliest experiment on spontaneous imitation. The experiment
involved a cat getting out of what he called a puzzle box by observing the successful
performance of others. A well-trained cat was placed in the box and an inexperienced cat
was allowed to watch the performance from an adjacent cage. The experiment was a dismal
failure. The observer cat was no better at getting out of the box than a naive animal. There was no
improvement in learning regardless of the number of observational trials. Thorndike obtained
similar negative results with chicks, dogs, and monkeys, and concluded that animals cannot learn by
observation.
This conclusion stalled experiments on animal imitation for some time. Then Herbert and Harsh
(1944) reported that cats could learn to solve manipulative problems by observation, if they observe
mistakes as well as successful performances. Cats that observed both mistakes and correct responses
by a model did better at problems than cats that only watched a skillful performance. When many
alternative responses are available, seeing what does and does not work seemed to be necessary for
observational learning (see Biederman & Vanayan, 1988, for an account of a similar effect with
pigeons).
Around the same time, Warden and his associates (Warden & Jackson, 1935; Warden, Fjeld, &
Koch, 1940) demonstrated imitation in rhesus monkeys. They trained monkeys by reinforcement to
solve puzzles that opened doors to reveal hidden raisins. When this performance was well established, a naive monkey watched a trained animal obtain raisins. Observation of the model produced
instantaneous solutions on 76% of the test trials. However, only the first instance of imitation could