Research in Autism Spectrum Disorders 2 (2008) 332–340
http://ees.elsevier.com/RASD/default.asp
The effect of context on imitation skills in
children with autism
Brooke Ingersoll *
Lewis & Clark College, United States
Received 10 August 2007; accepted 11 August 2007
Abstract
Children with autism exhibit deficits in imitation skills. Previous authors have suggested that they may
have particular difficulty imitating in natural social interactions, but properly controlled experiments
investigating this possibility have not been conducted. To investigate this possibility, children with autism
and typically developing children were compared on a series of imitation tasks presented either in a
structured-elicited or naturalistic-spontaneous condition. Modeled actions were counterbalanced across
conditions. Results suggest children with autism imitated less than typically developing children overall;
however, this difference was mainly evident when the imitation task was presented in a spontaneous context.
In addition, they exhibited less coordinated joint attention during imitation than the typically developing
children. These findings support the hypothesis that children with autism are particularly impaired in their
ability to imitate spontaneously.
# 2007 Elsevier Ltd. All rights reserved.
Keywords: Autism; Imitation; Social communication
Autism is a development disorder that is characterized by pervasive deficits in socialcommunicative behaviors, including language, pretend play, and joint attention (APA, 2000).
There is also a growing body of literature that demonstrates that children with autism have
deficits in imitation (see Smith & Bryson, 1994; Williams, Whiten, & Singh, 2004, for reviews).
Imitation deficits have been found on object (DeMyer et al., 1972; Stone, Ousley, & Littleford,
1997), body (DeMyer et al., 1972; Stone et al., 1997), vocal (Sigman & Ungerer, 1984), gestural
(Curcio, 1978; Sigman & Ungerer, 1984), and pantomime (Rogers, Bennetto, McEvoy, &
Pennington, 1996) tasks. Despite a few studies which have not found a clear imitation deficit in
* Correspondence address: 105B Psychology Building, Michigan State University, East Lansing, MI 48824, United
States. Tel.: +1 517 432 8412; fax: +1 517 432 2945.
E-mail address: [email protected].
1750-9467/$ – see front matter # 2007 Elsevier Ltd. All rights reserved.
doi:10.1016/j.rasd.2007.08.003
B. Ingersoll / Research in Autism Spectrum Disorders 2 (2008) 332–340
333
children with autism (Charman & Baron-Cohen, 1994; Morgan, Cutler, Coplin, & Rodrique,
1989), most researchers recognize imitation as a central deficit in children with autism (Smith &
Bryson, 1994) and a lack of imitative play is one of the diagnostic criteria for the disorder (APA,
2000).
Imitation research with individuals with autism has focused primarily on the form of imitation
(i.e., gestural, object, facial, vocal). These studies have suggested that some forms of imitation
are more impaired than others. For example, the imitation of body movements and gestures is
more impaired than actions with objects (e.g., DeMyer et al., 1972; Stone et al., 1997) and
imitation of non-meaningful actions is more impaired than meaningful actions (Rogers et al.,
1996; Stone et al., 1997). There are other elements relating to the use of imitation that may be
important to consider, specifically the context in which imitation occurs. Those few studies that
have investigated contextual factors have suggested that spontaneous imitation may be more
impaired than elicited imitation.
For example, Whiten and Brown (1998) found that children and adults with autism were
able to imitate on an elicited imitation task; however, they did not imitate as well as young
typical children and developmentally delayed children on a spontaneous imitation task. The
authors suggested that individuals with autism are capable of imitation, as evinced by their
imitation in the elicited condition, but lack the social motivation to imitate spontaneously.
Although these results are intriguing, this study was limited by the use of very different
imitation tasks in the two contexts; the elicited condition used manual gestures, while the
spontaneous condition used a three-step action on an object (opening an ‘‘artificial fruit’’
containing a treat). Thus the findings might also be interpreted to mean that individuals with
autism had more difficulty imitating a multiple-step object task than single step gestures. In
addition, the control groups were not matched for mental age with the individuals with autism,
making a direct comparison difficult.
McDuffie et al. (2007) examined immediate imitation skills in young children with autism in
three contexts: a structured-elicited condition, a naturalistic-spontaneous condition in which
children were alternately imitated by the examiner and presented with actions to imitate during
free play, and an instrumental condition in which children observed an experimenter activate a
mechanical device to produce lights and sound. They found that the children with autism imitated
significantly better in the structured-elicited and the instrumental condition than in the
naturalistic-spontaneous condition (Stone, Ulman, Swanson, McMahon, & Turner, 2004). They
also found that imitation on the structured-elicited and spontaneous-instrumental conditions was
associated with attention-following skills, while performance in the naturalistic-spontaneous
condition was associated with reciprocal social interaction as measured on the ADOS (Lord
et al., 2000). They concluded that children with autism are particularly impaired in their ability to
imitate when the function of imitation is purely social, as was the case in the naturalisticspontaneous condition. In addition, they suggested that use of imitation in different contexts is
mediated by different underlying skills (McDuffie et al., 2007; Rogers, Hepburn, Stackhouse, &
Wehner, 2003).
Again, a significant limitation to the interpretation in this study was the use of different
imitation tasks in the different contexts. For example, the structured-elicited task used the Motor
Imitation Scale (Stone et al., 1997), which contains single step object and gesture imitation tasks,
the naturalistic-spontaneous task used a standard set of toys with different actions modeled for
each participant based his or her play level, and the instrumental task used a different set of
objects which produced a sensory effect. Thus, it is unclear if differences in imitation in the
different contexts were due to the contexts themselves or the form of the actions modeled. For
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example, it is possible that the actions presented during the spontaneous conditions, were simply
more complex than actions presented in the elicited conditions. In addition, since there was no
control group in McDuffie et al. (2007) study, it is unclear if lower performance in a spontaneous
context is unique to autism or is also found in typically developing children.
If the above findings hold true, it would indicate that, while children with autism can imitate
(although not as well as typical children), they may rarely do so spontaneously. This finding
would suggest that imitation deficits may not be exclusively due to difficulty understanding and/
or representing what to imitate (form), but may also be due to difficulty selecting when to imitate.
Such a deficit would have implications for the underlying cause of the imitation deficit as well as
its treatment.
In this study, we replicated McDuffie et al.’s experiment for elicited and spontaneous imitation
tasks. We controlled for modeled actions by developing two sets of imitation tasks and
counterbalancing them across conditions. In addition, we included a control group of typically
developing children matched for non-verbal mental age. We hypothesized that the children with
autism would have a lower overall imitation performance than the typical children; however, the
children with autism would be more impaired in the spontaneous condition while the typically
developing children would imitate equally well in both conditions. Given the fact that both
Whiten and Brown (1998) and McDuffie et al. (2007) proposed that poorer imitation in the
unstructured condition may indicate that children with autism have difficulty using imitation for
social purposes, we also hypothesized that children with autism would appear less ‘‘social’’
during imitation than the typically developing children in that they would combine fewer
imitations with coordinated joint attention.
1. Methods
1.1. Participants
Seven young children with autism (six boys, one girl) and seven typically developing toddlers
(two boys, five girls) participated in this study. The participants with autism were recruited from
community treatment providers and ranged in age from 31 to 62 months (M = 37.4, S.D. = 8.8).
All children had been diagnosed with autism by a professional with expertise in autism not
associated with this project. Diagnoses were confirmed by the first author using DSM-IV-TR
(APA, 2000) criteria. The Childhood Autism Rating Scale (CARS; Schopler, Reichler, DeVellis,
& Daly, 1980) was also administered by the first author to determine the range of autism severity
in the participants with autism. Their mean CARS score was 35.8 (S.D. = 4.1), placing the
children in the mild-moderate range of autism severity.
The typical participants were recruited from the community via flyers and email postings and
ranged in age from 21 to 30 months (M = 26.6, S.D. = 3.3). Chronological age was significantly
higher for the autistic than the control group, t(12) = 4.57, p < 0.001. The typical participants
and participants with autism were group-matched for non-verbal mental age using the Mullen
Early Learning Scales (Mullen, 1995). Mean non-verbal mental age was 27.3 (S.D. = 9.2)
months for the participants with autism and 28.6 (S.D. = 5.0) months for the typically developing
children. A two-tailed, independent samples t-test indicated no significant difference,
t(12) = 0.32, p = 0.75, in non-verbal mental age equivalents between groups. Although the
typically developing children (M = 29.3, S.D. = 4.0) had a higher average language age than the
children with autism (M = 21.0, S.D. = 11.4), this difference was not significant, t(12) = 0.32,
p = 0.09. Ethnic distribution and social economic status did not differ between groups.
B. Ingersoll / Research in Autism Spectrum Disorders 2 (2008) 332–340
335
1.2. Procedure
Participants were assessed in a quiet room. After a brief warm-up period with several toys,
participants were administered two imitation conditions: an elicited task and spontaneous task.
The order of administration of the tasks was counterbalanced across participants. One of two sets
of 10 toys was used in each condition. Toy sets were counterbalanced across participants, such
that if one child received one set of toys in the elicited condition, another child would receive the
same set in the spontaneous condition.
1.3. Tasks
1.3.1. Elicited imitation task
The elicited imitation task was adapted from the structured-elicited imitation procedure
described by McDuffie et al. (2007). Participants were seated at a table with a 908 angle from the
examiner. Before the task began, the examiner said, ‘‘I have some toys to play with. Watch
closely and do what I do.’’ Before each trial, the examiner said, ‘‘Watch me’’ and then modeled
the action and corresponding verbal marker. The toy was then presented to the child for 10-s and
the child was instructed, ‘‘You do it.’’ Each action was modeled three times regardless of the
child’s response and all toys were presented in random order.
1.3.2. Spontaneous imitation task
The spontaneous imitation task was adapted from the naturalistic-spontaneous imitation
procedure described by McDuffie et al. (2007). Participants were seated on the floor. The
examiner had two pairs of each toy freely available. Before the task began, the examiner said, ‘‘I
have some toys to play with. We can play together.’’ Then, the examiner imitated all of the child‘s
play with a duplicate toy for 2 min. After the initial contingent imitation period, the adult began
to model actions with toys. Before each trial, the examiner said ‘‘Watch me’’ and then modeled
an action and its verbal marker followed by a 10-s response period. Each action was modeled
three times regardless of the child’s subsequent behavior. After the third model, the examiner
returned to imitating the child for 45 s before presenting a new model. Toys were presented in
random order; however, the examiner refrained from modeling an action with the toy that the
child was currently engaged with.
1.4. Materials
Twenty age-appropriate toys were selected for this study. Each toy was assigned a specific
modeled action and related verbal marker. The actions were designed to be interesting to toddler
and preschool age children. Although some actions were those commonly associated with the toy
(e.g., feeding a teddy bear food), the majority of actions were novel (e.g., placing a pom–pom on
the head). Ten toys were chosen for each set. Each set contained a similar number of
sensorimotor, functional, and symbolic actions matched for theme and complexity (see Table 1).
1.5. Scoring
Scoring definitions for imitative responses were taken from the description provided for Stone
et al.’s (1997) Motor Imitation Scale. Responses were scored on a 3-point scale: a ‘‘2’’ was
recorded if the child produced exact imitation, a ‘‘1’’ was recorded if the child produced an
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Table 1
Imitation tasks and materials
Toy
Action
Verbal marker
Set 1
Nesting cups
Teddy bear and food
Slinky
Tamborine and rattle
Garland
Train
Recorder
Fish and net
Light tube
Squishy ball
Hit bottom of two cups together
Feed bear
Put on nose
Hit tambourine with rattle
Put around neck
Roll off table
Blow and move fingers
Place fish in net
Spin around in air
Roll back and forth on table
Bang, bang
Teddy’s hungry
Look at my nose!
Ta da!
I have a scarf
Oh no, it fell!
I’m playing music
I caught a fish
Whoa!
Roll, roll
Set 2
Nesting eggs
Baby and blanket
Pom–pom
Musical triangle
Teething ring
Car
Party favor
Blocks and container
Sound tube
Koosh ball
Spin
Cover baby
Put on head
Strike stick in middle
Put around wrist
Crash into wall
Blow
Place block in container
Turn upside down
Hold by string and bounce
Spin, spin
Baby’s tired
Look at my hair!
Ding, ding!
I have a bracelet
Uh oh, it crashed!
Happy birthday!
In it goes
Whee!
Bounce, bounce
emerging response (e.g., the child attempted to manipulate the toy in the correct manner, but
failed to complete the act exactly as modeled), and a ‘‘0’’ was recorded if the child failed to
imitate. For each toy, only the best trial was recorded. Overall imitation scores could range from 0
to 40 (maximum score with all 20 toys); scores for each task could range from 0 to 20 (maximum
score with 10 toys). Coordinated joint attention was scored from videotape as occurrence/nonoccurrence for each imitation trial.
Inter-rater reliability was calculated for 30% of the observations using Pearson’s r. Observers
(undergraduate research assistants blind to the participants’ diagnoses) were trained to 80%
reliability on training tapes across three consecutive scoring trials. The correlation for imitation
was 0.96 on the social task and 0.99 on the structured task. The correlation for coordinated joint
attention was 0.96 on the social task and 0.95 on the structured task. All p’s were less than 0.05.
2. Results
We examined whether the groups differed in their imitation ability using a 2 (diagnosis) 2
(task) mixed model ANOVA. Consistent with the first prediction, there was a main effect of
diagnosis on overall imitation performance, F(1,12) = 5.84, p = 0.032; h2p ¼ 0:33, such that
typical children received a higher overall mean imitation score (M = 30.14, S.E. = 1.54) than the
children with autism (M = 18.86, S.E. = 2.92). A main effect of task was also found,
F(1,12) = 5.88, p = 0.032; h2p ¼ 0:33, such that the children imitated more on the elicited
(M = 13.57, S.E. = 1.51) than spontaneous task (M = 10.93, S.E. = 1.50). However, this effect
was driven by a significant interaction of group diagnosis by task, F(1,12) = 5.26, p = 0.041;
B. Ingersoll / Research in Autism Spectrum Disorders 2 (2008) 332–340
337
Fig. 1. Mean imitation score as a function of diagnosis and task.
h2p ¼ 0:31, suggesting the task had a differential effect of the two groups’ imitation performance.
The effect sizes for all comparison are considered large (Cohen, 1988). Follow-up Bonferroni ttests indicated that, for the typical participants, imitation performance on the spontaneous task
(M = 15.00, S.E. = 1.07) was not significantly different from performance on the elicited task
(M = 15.14, S.E. = 1.55), t(6) = 0.093, p = 0.93. However, the participants’ with autism scores on
the spontaneous imitation task (M = 6.87, S.E. = 1.77) was significantly lower than their
performance on the elicited task (M = 12.00, S.E. = 2.57), t(6) = 3.32, p = 0.02. No significant
difference was found between the typical participants (M = 15.14, S.E. = 1.55) and the
participants with autism (M = 12.00, S.E. = 2.57) on performance on the elicited task,
t(12) = 1.05, p = 0.32. However, the participants with autism (M = 6.87, S.E. = 1.77) and typical
participants (M = 15.00, S.E. = 1.07) differed significantly in their imitation performance on the
spontaneous imitation task, t(12) = 3.95, p = 0.002 (see Fig. 1).
We also examined the children’s use of coordinated joint attention on those trials in which they
imitated (imitation score of 1 or 2) using a 2 2 mixed model ANOVA. There was a main effect
of diagnosis, F(1,12) = 22.11, p < 0.001; h2p ¼ 0:65, such that the typical children used
Fig. 2. Mean percent of imitations accompanied by coordinated joint attention.
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significantly more coordinated joint attention (M = 56.36%, S.E. = 7.23) than the children with
autism (M = 14.0%, S.E. = 5.37). There was no main effect of task, F(1,12) = 1.58, p = 0.23, or
interaction, F(1,12) = 0.40, p = 0.54. The effect size for diagnosis is considered large (Cohen,
1988) (Fig. 2).
3. Discussion
This study examined the use of elicited versus spontaneous imitation in children with autism
by manipulating the context in which the tasks were presented. Consistent with previous
research, the children with autism imitated significantly less than the typically developing
children. However, unlike the typically developing children who imitated equally well in both
conditions, the children with autism imitated significantly worse in the spontaneous condition. In
addition, the children with autism displayed significantly less coordinated joint attention with the
examiner during imitation than the typically developing children.
Our findings are consistent with other research indicating children with autism are more
impaired on spontaneous than elicited imitation tasks (McDuffie et al., 2007; Whiten & Brown,
1998). In previous studies, actions modeled in elicited versus spontaneous conditions were
different. In the current study, through the use of counterbalancing, we were able to use the same
actions and objects in each condition, ruling out the possibility that inherent differences in the
difficulty of the modeled action accounted for differences in imitation performance. Instead, the
only difference in the tasks was the context in which they were presented.
Why are children with autism more impaired on spontaneous imitation tasks? One
explanation is that these children lack the social motivation to share experiences or to be like
others (Hobson & Lee, 1999). It is this social motivation that naturally draws typically
developing children into imitative interactions (Carpenter, 2006; Ingersoll, Schreibman, & Tran,
2003). In the elicited task, the children were given the explicit instruction to imitate the
experimenter’s behavior. Thus, imitation in this condition may have represented compliance with
adult directions. However, in the spontaneous task, the experimenter engaged the children by
imitating their behavior, but did not provide any instructions for the child. Thus, imitation in this
condition may have represented the child’s desire to connect with the adult. Indeed, while it could
be argued that all imitation is inherently elicited since it occurs in response to a model,
‘‘spontaneous’’ imitation requires the imitator to select when to imitate in the absence of explicit
cues. Perhaps children with autism exhibit particular difficulty in this selection process because
they lack the motivation to engage with others. This interpretation would suggest that children
with autism are particularly impaired in their use of imitation for social purposes, a hypothesis
which has been proposed elsewhere (Ingersoll, in press; Ingersoll et al., 2003; McDuffie et al.,
2007; Rogers et al., 2003). Our finding that the children with autism exhibited significantly lower
rates of coordinated joint attention during imitation also supports this interpretation; it suggests
that even when children with autism do imitate, their imitation appears less ‘‘social’’ and may be
an indication of a lack of interest in sharing the imitation experience with the partner.
It is also possible that spontaneous imitation deficits in autism result from a failure to visually
attend to others during spontaneous interactions (Rogers et al., 2005). This failure to attend may
be due to a decreased social interest (e.g., Ingersoll, in press) or abnormal attention shifting
(Landry & Bryson, 2004). Either way, a pervasive lack of visual attention to others during natural
interactions may disrupt imitation development, particularly for spontaneous tasks. Alternately,
poor imitation skills may lead to a lack of visual attention to others or may parallel imitation
deficits (Rogers et al., 2005).
B. Ingersoll / Research in Autism Spectrum Disorders 2 (2008) 332–340
339
Another potential explanation involves the intervention strategies used for teaching imitation
skills to young children with autism. Most early intervention programs include direct instruction
in imitation skills using highly structured teaching procedures which closely resemble the
structured condition in our study (Ingersoll, in press). Indeed, most of the children with autism in
our study had received some structured imitation training prior to participation. Thus, imitation
training may have facilitated performance in the elicited condition. However, if this is the case, it
is clear that imitation did not generalize to the spontaneous condition. This finding may be
indicative of poor generalization skills (Schreibman, 1988) or the fact that spontaneous imitation
is more impaired and thus less amenable to intervention. Either possibility indicates that
imitation interventions should target imitation within a social, spontaneous context in order to
produce meaningful improvements in the spontaneous use of imitation (Ingersoll, in press;
Ingersoll & Schreibman, 2006).
Several limitations of this study are acknowledged. First, the small number of participants in
each group may have resulted in a Type II error. With a larger sample, we may have found
significant differences between the typical children and children with autism on the elicited task
as well. However, the fact that we found a significant interaction with such a small sample
suggests that, even with a larger sample, there would be a discrepancy between the children with
autism’s performance on the elicited and spontaneous tasks. Second, the children with autism and
typical children were matched on non-verbal mental age rather than language age. Several
researchers have suggested that, due to the close association between imitation and language,
matching for language age may be a more conservative strategy (Smith & Bryson, 1994; Stone
et al., 1997). Further, the groups were not matched on gender with the typical group having a
significantly higher number of females than the group with autism. Future research should
explore possible differences in findings as a function of language and gender.
Third, diagnoses of autism were made by community diagnosticians and confirmed by the
author using the DSM-IV-TR criteria and the CARS rather than the ADOS (Lord et al., 2000).
Although we are confident that our sample was representative of the autistic population,
additional research using a more rigorous diagnostic protocol is needed.
Another limitation of this study is the lack of inclusion of a group of developmentally delayed
controls. Finally, the young age of the participants prevents generalization to the autistic
population as a whole. It is possible that as children age, different deficits contribute differentially
to imitation problems. Replications of this finding including both typical and developmentally
delayed language age-matched controls of varying ages would offer more convincing support.
Acknowledgements
This study was supported by a grant from Cure Autism Now. I am grateful to the children and
their families who participated in this research as well as the undergraduates who assisted in the
data collection.
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