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RESEARCH ARTICLE
Mother–infant co‐regulation in dyadic and triadic
contexts at 4 and 6 months of age
Tiziana Aureli
1
|Fabio Presaghi
2
|Maria Concetta Garito
1
1
Department of Neuroscience and Imaging,
DNI, University of Chieti‐Pescara, Pescara,
Italy
2
Department of Psychology of Development
and Socialization Processes, Roma, “La
Sapienza”, Rome, Italy
Correspondence
Tiziana Aureli, Department of Neuroscience
and Imaging, DNI, University of Chieti‐Pescara,
Italy.
Email: t.aureli@unich.it
Abstract
This study examined interpersonal co‐regulation in 80 mother–infant
dyads when interacting face‐to‐face and with an object, at the infant
ages of 4 and 6 months. We found that co‐regulation patterns
differed between conditions and with development. Under the
dyadic condition, the dyads were mostly unilateral, with only the
mother attending to the infant's focus, while in the triadic context,
they were mostly symmetrical, with both mother and infant mutually
engaged. While confirming previous studies showing that interper-
sonal co‐ordination is a relatively rare event in face‐to‐face
exchanges, this result shows that the contrary is instead true when
objects are available. Also, unilateral co‐regulation significantly
increased in the triadic context from 4 to 6 months, together with
an increase in the active role of the infant during symmetrical
exchanges. The development of manipulative skills that occurred
during this age period might have promoted these co‐regulation
changes, through improvement of the infant activities with objects,
both independently and with the mother. Finally, involvement in
triadic interactions appears to relate to temperamental aspects, being
favoured by the infant's disposition to be soothed by the caregiver.
Overall, our results support the view of early social development as
a context‐based and multidimensional process.
Highlights
•Investigation of how mothersand infants co‐regulate in face‐to‐face
interactions and with toys in the first 6 months of life.
•Eighty mother–infant dyads are observed longitudinally in dyadic
and triadic interactions at 4 and 6 months of age.
•Social‐mediated object exchanges favour symmetrical co‐regulation
in early mother–infant interactions, whereas unilateral co‐regulation
prevails in face‐to‐face contexts.
KEYWORDS
face‐to‐face and with toys interactions, interpersonal co‐regulation
patterns, temperament and co‐regulation relationship
Received: 9 October 2016 Revised: 21 October 2017 Accepted: 29 October 2017
DOI: 10.1002/icd.2072
Inf Child Dev. 2017;e2072.
https://doi.org/10.1002/icd.2072
Copyright © 2017 John Wiley & Sons, Ltd.wileyonlinelibrary.com/journal/icd 1of14
1|INTRODUCTION
The transition of infants from dyadic to triadic interactions marks a pivotal change in early communicative development.
Dyadic interactions—as person‐to‐person—emerge very soon in postnatal life, at around 2 to 3 months of age, and allow
mothers and infants to exchange facial, postural, and vocal expressions in the face‐to‐face context (Cohn & Tronick,
1987; Van Egeren, Barrat, & Roach, 2001). Triadic interactions—as person‐to‐person‐to‐object—engage the partners in
communication about something that is external to the purely interpersonal context,and these interactions are commonly
observed some months later, at about the end of the first year of life (Carpenter, Nagell, & Tomasello, 1998; Trevarthen
& Hubley, 1978). While dyadic interactions only convey emotional and affective content, triadic interactions allow
sharing of intentions and meanings, thus moving communication beyond the body boundaries to the use of symbols.
According to the social cognitive perspective (Tomasello, 1995, 1999; Tomasello, Carpenter, Call, Behne, & Moll,
2005), the ability to participate in triadic interactions emerges at about the end of the first year of life, when infants
are involved in joint attention episodes. However, infants appreciate the triadic structure of the interactive context
well before this age. As shown by a number of behavioural studies, infants can follow other people's visual attention
towards external objects by 3 months of age (D'Entremont, Hains, & Muir, 1997; Hains & Muir, 1996; Hood, Willen, &
Driver, 1998). This ability improves in the subsequent few months, with infants becoming capable of actively
coordinating their visual attention between people and objects (Flom & Pick, 2005; Striano & Bertin, 2005), and
perceiving the link between the two (Woodward, 1998). Moreover, infants can distinguish face‐to‐face interactions
from person–object interactions by 3 months of age and can also discriminate between different kinds of
person–object interactions (Striano & Stahl, 2005).
Further support for early triadic ability is provided by neuroimaging data. Studies on event‐related potential have
shown that at 4 months of age, the brain activity related to attentional processes is higher when an infant looks at an
object that an adult did not look at, compared to an object that the adult did look at. This suggests that a cued object is
perceived as more familiar than an uncued object (Reid, Striano, Kaufman, & Johnson, 2004). Consistent with this,
attention‐related brain activity at 5 months is greater under the joint attention condition where the experimenter
alternates their gaze from the object to the infant's eyes, than under the non–joint‐attention condition (Parise, Reid,
Stets, & Striano, 2008). Recent studies using near‐infrared spectroscopy (see Lloyd‐Fox, Blasi, & Elwell, 2010, for
details) have complemented these data by showing that by the age of 4 months (as also seen with adults), a specific
area in the left dorsal prefrontal cortex is recruited when infants are presented with joint attention conditions, as com-
pared to conditions where there is no referent or eye contact involved (Grossmann & Johnson, 2010).
While experimental studies have revealed that infants are sensitive to key components of the triadic context very
early in their development, observational studies have consistently shown that they can also be involved in person–
person–object exchanges this early. As shown by the pivotal study of Trevarthen and Hubley (1978), objects are
incorporated into mother–infant games by 4 months of age. Later, Lyra and Rossetti‐Ferreira (1994) consistently
observed that mothers introduce objects into face‐to‐face play by 3 months of age. The recent review by Fogel,
Garvey, Hsu, and West‐Stroming (2006) of the few studies that have focused on the social involvement of objects
at an infant age of under 6 months also reported that object play intersperses mother–infant interactions by 5 months
of age. Even more recently, de Barbaro, Johnson, and Deák (2013) confirmed this picture. By collecting systematic
observations of the real‐time activities in mother–infant free play from the infant age of 4 to 12 months, they detailed
the way in which the infants become progressively able to follow routines that involve both people and objects, and
the way in which the mothers adapt their interactive behaviour to the growing skills of the infant.
The beginning of infant involvement in early social‐mediated object exchanges can relate to the concurrent
improvement of motor skills. In particular, two motor domains strongly improve in this age period: object manipulation
and postural control. For object manipulation, the strengthening of eye‐hand and hand‐mouth coordination and the
emergence of systematic handling and grasping of objects (Rochat & Goubet, 1995) allow infants to contact objects
in a more active way than previously (Rochat, 1989), thus promoting their interactions with the physical reality
(Bushnell & Boudreau, 1993; Palmer, 1989). For postural control, experimental (Fogel, Dedo & McEwen, 1992) and
2of14 AURELI ET AL.
naturalistic (Fogel, Messinger, Dickson, & Hsu, 1999; Fogel, Nwokah, Hsu, Dedo, & Walker, 1993; Kaye & Fogel, 1980;
Savelsbergh & van der Kamp, 1993) studies have shown that the increasing ability to remain in an upright position
allows the infants to be more likely to gaze at the surroundings and to reach for available objects, compared to when
they are in reclined or supine positions. Both of these changes in the motor domain might influence the mother–infant
interactions. As consistently reported by a number of very careful, although older, observational studies (Adamson &
Bakeman, 1985; Bakeman & Adamson, 1984; Kaye, 1982; Kaye & Fogel, 1980; Trevarthen, 1984), infant attention to
the mother's face during dyadic interactions declines by 3 to 4 months of age, in favour of the attention to the environ-
ment, and the portion of the infant's time spent looking away from the mother is more often spent attending to objects
(Cohn & Tronick, 1987). This shift appears to contribute to the opening of the dyadic context to the external reality.
Based on the habituation paradigm, Libertus and Needham (2014) recently reported a clear visual preference for a
face compared to a toy in 5‐month‐old infants, so apparently counteracting the above results. It might be that at this
age the human face represents a more salient stimulus than the object when the infant looks at the two in an exper-
imental paradigm based on the salience of a picture; however, when the objects are available for manipulation, they
could be preferred to the person for interacting. Indeed, infants at this age contact objects in a more efficient way
then previously, thus being able to use manipulation for exploring a reality that is still largely novel for them and
presumably more attractive compared to the quite familiar human face.
The parents have a relevant part in the opening of the dyadic context to triadic interactions. As noted by the
pivotal study of Kaye and Fogel (1980), the mothers appear to easily capture the shift in the infant's attention from
their face to the object, which occurs at around 4 months. Indeed, while they try to catch and hold the infant's atten-
tion towards themselves at 6 weeks, they try to incorporate the attended objects into play at 26 weeks. Accordingly, a
number of subsequent observational studies (de Barbaro et al., 2013; Fogel et al., 2006; Lyra & Rossetti‐Ferreira,
1994) reported that when mothers are interacting with their infants early in the first year of the infant life and in a
context where objects are available, they are likely to spent time in object–infant interactions. The mothers bring
the toys nearer to the infants to favour manual contact with them, they move the toys in front of the infant to convey
the infant's attention to them, and they manipulate the toys to reveal their properties. Therefore, although dyadic
interactions are the most notable occasions for social exchanges at an early age, triadic interactions are in place as
well, and infants show to appreciate a triadic way of experiencing reality well before they become able to share atten-
tion and action in fully fledged episodes of joint activity.
How mother–infant interactions unfold at an early age under both dyadic and triadic conditions is far from being
fully analysed. We know a lot about the dyadic interactions that occur in the first few months of an infants' life, and a
lot about the triadic interactions that occur later, at around the end of the first year. However, we know much less
about what happens in‐between. Here, the infant involvement in triadic interactions begins when the dyadic are also
present, and, as the structure and the content of the two are different, it is reasonable to presume that they develop in
somehow different ways. Therefore, what we know about mother–infant interactions in dyadic situations might not
be equally true in triadic situations.
To add to our knowledge of how infant social experience is at an early age, the present study analysed longitu-
dinally mother–infant interactions in face‐to‐face (i.e., dyadic) and with objects (i.e., triadic) contexts at 4 and 6 months
of infant age. With reference to the view (Fogel, 1993, 2000) of communication as a relational event that unfolds
through the partners continuously adjusting to each other, we selected mother–infant co‐regulation as the key
feature of their interactive experience. Accordingly, the data were analysed with the Relational Coding System (Fogel,
1994), which distinguishes different co‐regulation patterns based on the quality of the interpersonal adjustment. In
particular, there are three patterns that are of particular note: unilateral (one partner pays attention to the other, while
the other attends to something else); asymmetrical (only one partner is involved in the activity, while the other simply
observes); and symmetrical (both partners are mutually engaged in a common activity). To observe these processes in
more detail, we used the revised version of this system (Fogel et al., 2003), which adds subcategories to the main codes.
The main aim of the study was to compare co‐regulation in dyadic interactions and in triadic interactions. As
previous studies on face‐to‐face exchanges have consistently shown that unilateral co‐regulation is the most frequent
AURELI ET AL.3of14
pattern in the age period under study (Evans & Porter, 2009; Hsu & Fogel, 2003; Silvén, 2001), we expected that this
pattern would prevail over the asymmetrical and symmetrical under dyadic conditions. Due to the emerging attractive
power of objects, we would expect the same result under the triadic condition too. However, due to the mother's role
in favouring the infant's contacts with objects, the opposite could occur, with a higher presence of asymmetrical and
symmetrical co‐regulation patterns compared to unilateral ones.
Based on the longitudinal design of the study, an additional aim was to investigate the co‐regulation stability in
both contexts. According to previous studies, co‐regulation is little affected by the long‐term history of the
mother–infant communicative experience (Hsu & Fogel, 2003); therefore, we expected to find no significant correla-
tions between 4 and 6 months of age, independent of context. Finally, as the infant temperament influences early
interactions (Putnam, Sanson, & Rothbart, 2002), since easier children might be more likely to have supportive parents
and more difficult children might have more rejecting parents, we expected that the infants who were higher in
regulation would be more able to engage in coordinated, symmetrical interactions than the lower infants, irrespective
of the social context (dyadic or triadic) in which they were involved.
2|METHOD
2.1 |Participants
One hundred mothers were recruited from a public hospital in an urban area located along the central‐eastern coast of
Italy. All of the mothers were approached within 2 days of the birth of their baby, and asked to fill in a questionnaire
that included demographic information. They were then informed about the project and asked for their agreement to
participate in the present study. Eighty mother–infant dyads (80% of the mothers contacted) agreed and gave their
informed consent. No differences with respect to the educational level, age, language, and social status were found
between the mothers who agreed to participate and those who declined to participate. For the mothers who entered
the study, their mean age was 34.67 years (SD, 4.56 years; range, 24–44 years), their mean length of education was
14.93 years (SD, 2.99 years; range, 8–18 years), and 75% (N= 45) of them had a stable job (the remaining mothers
either had temporary jobs or were not employed). Also, 84% (n= 67) had medium to high income, with fewer on a
low income (n= 13).
For the infants, 51% (N= 41) were male and 58% (N= 48) were firstborn. All of the infants were born full‐term,
and none had medical complications at birth, had experienced hospitalization, or had been diagnosed with medical or
psychological delays/ disorders. All of the infants belonged to bi‐parental Italian families, where the mothers were
their primary caregivers, and the fathers were actively engaged in the child‐care.
2.2 |Procedures
The mother–infant dyads were observed longitudinally when the infants were 4 months old (mean age, 3;9 months,
SD, 0;5; girls: mean age, 4;0 months, SD, 0;5; boys: mean age, 3;8 months, SD, 0;5) and 6 months old (mean age,
5;9 months, SD, 0;4; girls: mean age, 5;9 months, SD, 0;8; boys: mean age, 5;7 months, SD, 0;4).
The mothers were contacted by telephone twice: when their infants were about 4 months of age and 2 months
later. On both occasions, they were invited to the baby laboratory to take part in a videotaped interaction session. The
mothers were asked to play with the infant as they normally would at home. The infants were placed in an infant seat
positioned on a table, facing their mother. During the first 5 min, the mothers engaged in face‐to‐face interactions,
and for the following 5 min, they were provided with three age‐appropriate toys (i.e., a soft toy, a maracas, and a
rattle), which they could use as they wanted during the interactions. Three cameras were used to film each play
session. The first camera was focused on the face of the mother, the second on the face of the infant, and the third
recorded the general situation. The outputs from the three cameras were assembled through a special effects
generator to produce a split‐screen image with a timer superimposed on the screen.
4of14 AURELI ET AL.
2.3 |Mother–infant co‐regulation
Mother–infant interactions were coded using the revised Relational Coding System, which was developed by Fogel
et al. (2003) to capture the quality of the interactive involvement between mothers and infants over time (Fogel &
Lyra, 1997; Hsu & Fogel, 2003). This ranges from the absence of orientation of one partner to the other, to the mutual
and continuous adjustment of their respective actions.
The first edition of the coding system (Fogel, 1994) included five global categories of communicative interactions:
unilateral, asymmetrical, symmetrical, disruptive, and unengaged (see Table 1). This has been subsequently revised to
include subcategories, such as following, initiating, and demanding for unilateral co‐regulation; demonstrating and
expecting for asymmetrical; sequential and resonant for symmetrical (Fogel et al., 2003).
In analysing these data, we recognized that symmetrical sequential co‐regulation (continuous participation of the
two partners, with each engaging in actions that are contingent to the other's actions) occurred in two main ways: with
the infant simply accepting the mother's offer (e.g., grasping the object presented by the mother), or with the infant
adding something new (e.g., shaking the presented object, once accepted). While shared focus is achieved in both cases,
in the former case (grasping) the infant limits the interaction to receiving the mother's communicative bid, whereas in
the latter case (shaking) the infant also elaborates upon it. Therefore, although both behaviours fall under the same
category (i.e., symmetrical), only the second one fully meets the main criterion for coding a co‐regulation pattern as
symmetrical (i.e., the innovative quality of the partner contribution). As the difference in the quality of symmetrical
exchanges revealed by our data might be due to the infant's age and ability, we followed the recommendation of Fogel
et al. (2003) to take into account these aspects when coding the behaviours. We therefore decided to recode symmet-
rical exchanges by distinguishing the roles of the infant as accepting or innovating, respectively.
According to the coding manual (Fogel et al., 2003), episodes of co‐regulation lasted at least 2 s and were iden-
tified from the action of one partner followed by the opportunity for the other partner to participate. The resulting co‐
TABLE 1 Co‐regulation coding system (adapted from The Revised Relational Coding System, Fogel et al., 1993)
Codes Description
Symmetrical Both partners adjust their communicative actions to the continuously changing actions of the partner and
engage in active, mutual engagement, and shared experience via vocal and non vocal behaviours:
(a) symmetrical‐resonant is characterized by a high level of spontaneity and simultaneity of the actions,
emotions, and attention (e.g., I makes a funny face; M bursts out into laughter and I smiles at the same
time);
(b) symmetrical‐accepting has a sequential way of proceeding, with the infant responding to the mother's
communicative signals (e.g., M offers an object to I; I takes the offered object and holds it);
(c) symmetrical‐innovating has a sequential way of proceeding, with the infant responding to the mother's
communicative bids by adding something new (e.g., M offers an object to I; I takes the offered object and
smiles looking to the M).
Asymmetrical One partner is merely attending to the other without responding to the other's moves:
(a) asymmetrical‐demonstrating: one partner is innovative (e.g., demonstrating a toy). The other partner
observes the first, but is otherwise not actively engaged;
(b) asymmetrical‐expecting: one partner is innovative by creatively initiating a theme (e.g., vocalizing). The
other partner observes the first but does not actively participate (e.g., does not respond).
Unilateral Only one partner tries to engage the other, who is absorbed in the own activity and does not pay attention
to the partner or respond to the partner's initiations:
(a) unilateral‐following, when the active partner is available to notice and support the other (e.g., I looks to an
object and acts upon it; M says: “Yes, it is nice! isn't it?”
(b) unilateral‐initiating, with the active partner initiating an interaction, without receiving any response from
the other (e.g. M says “Looks at the teddy bear! You can take it”; I continues to be engaged with a ring)
(c) unilateral‐demanding, with the mother initiating an interaction by using repetitive requests, and/or a
compelling tone of the voice, and/or an intrusive quality of touch.
Disruptive One partner disturbs the ongoing flow of action of the other partner in such a way that their interaction
becomes disrupted (e.g., I puts a toy in their mouth and M forcefully takes it out, after which I becomes
distressed).
Unengaged Partners are simultaneously engaged in acting with respect to self and not with respect to each other.
No code Missing information required for coding.
AURELI ET AL.5of14
regulation patterns were defined as in Table 1. The patterns were coded every second from the videotapes by a
trained coder, using the Mangold Interact 8 software (version 8.1.3). An independently trained coder processed
25% of the sessions to compute inter‐observer reliability. The Kappa values were calculated for each code under each
condition at each age and ranged from .86 to .94. The low frequency of disruptive episodes—only one occurrence (2 s)
—and Unengaged episodes—10 occurrences, for 158 s in total—resulted in their exclusion from the analysis.
2.4 |Infant temperament
Infant temperament was measured using the Italian short version [blinded for review] of the IBQ‐R (Gartstein &
Rothbart, 2003). This is a rating questionnaire for which the parents of an infant are asked to report the frequency
of infant behaviours that occur over a 2‐week period prior to the first laboratory visit, using a 7‐point scale ranging
from 1 (never)to7(always). All of the mothers involved in the study were asked to fill in this questionnaire when their
infants were 4 months old (with 2 weeks tolerance), and 90% of them did so. Our research interest was in the possible
relationships between interpersonal co‐regulation and the infant's regulatory functioning, in terms of the ability of the
infant to easily face external and internal stimuli. Therefore, only the IBQ‐R measures that defined this ability were
considered. According to the factor analysis conducted by the authors of both the original (Gartstein & Rothbart,
2003) and Italian [blinded for review] versions, the Regulatory factor emerged as one of the three dimensions that
defined the IBQ scores, with Surgency and Negative affectivity being the other two. Therefore, we considered only
the scales included in this factor. They are the following: Cuddliness, as the infant's expression of enjoyment and
moulding of the body when held by the caregiver; Soothability, as the reduction in the infant's fussing, crying, or dis-
tress when soothing techniques were used by the caregiver; Perceptual Sensitivity, as the infant's detection of slight,
low intensity stimuli from the external environment; Low Intensity Pleasure, as the infant's amount of pleasure or
enjoyment related to low stimulus intensity, rate, complexity, novelty, and incongruity; and Duration of Orienting,as
the infant's attention to and/or interaction with a single object for extended periods of time.
2.5 |Analysis strategy
The proportional durations of each co‐regulation pattern at each age under each condition were used as dependent
variables. Therefore, the total number of seconds spent by the dyad in a given category in each session was divided
by the total number of seconds in the session. Preliminary analysis for the normality of the data (investigated through
Shapiro–Wilk tests of normality) indicated a high degree of deviation from a normal distribution. More specifically, the
S‐W statistics ranged from .868 for the asymmetrical pattern at 6 months under the triadic condition to .981 for the
unilateral pattern at 4 months under the dyadic condition. Therefore, arcsin transformation was applied to all of the
variables (Sokal & Rohlf, 1981). After this transformation, only one variable still showed a significant Shapiro–Wilk
test: the Total Unilateral proportional duration at 6 months. Unilateral, asymmetrical and symmetrical co‐regulation
codes and sub‐codes of each of the three co‐regulation patterns were considered for the analyses. ANOVA was per-
formed to define the effects of co‐regulation, Condition (Dyadic vs. Triadic), and Time (4 months vs. 6 months) on the
proportional durations. For post‐hoc tests, the nominal alpha was corrected by the Bonferroni method, by controlling
for the number of pairwise comparisons performed. We also analysed the relationships between the co‐regulation
patterns and between co‐regulation and temperament. In this case, Spearman correlation coefficients were computed
and their significance was also tested by applying Bonferroni correction for multiple correlations.
3|RESULTS
Preliminary analyses showed no significant differences in any of the observed variables with respect to infant gender;
therefore, no further analysis was carried out according to gender. We first analysed co‐regulation, and then the
relationships between co‐regulation and temperament.
6of14 AURELI ET AL.
3.1 |Mother–infant co‐regulation
Three communication patterns accounted for most of the occurrences: unilateral, asymmetrical, and symmetrical (see
Table 2 for descriptive statistics of the main codes and sub‐codes). We first analysed these codes, and then their
sub‐codes.
3.1.1 |Main codes
As the research design involve a 2 (age points) × 2 (conditions) × 3 (co‐regulation) repeated measures ANOVA, we first
present the main effects, followed by the two‐way interaction effects, and finally the three‐way interaction effects.
The main effect of co‐regulation was significant (F(2, 78) = 36.82, p< .01, η
2partial
= .49), as well as the context (F(1,
79) = 84.63, p< .01, η
2partial
= .52). However, the main effect of age was non‐significant (F(1, 79) = 1.78, p= .19,
η
2partial
= .02).
Turning to the two‐way interaction effects, the co‐regulation pattern by context interaction was significant (F(2,
78) = 20.09, p< .01, η
2partial
= .34), as was the interaction between co‐regulation pattern and age (F(2, 78) = 29.37,
p< .01, η
2partial
= .43). However, the interaction between context and age was not significant (F(2, 78) = 3.51,
p= .07, η
2partial
= .04). Finally, the three‐way interaction effect was significant (F(2,78) = 4.62, p= .013, η
2partial
= .11;
see Figure 1). To better investigate this interaction, we decomposed it into its simple effects (Keppel, 1991), thus
considering the co‐regulation patterns by condition at each of the two ages (4 vs. 6 months). At 4 months there were
significant differences between the co‐regulation in the dyadic context (F(2, 78) = 3.60, p= .03, η
2partial
= .09), with
unilateral co‐regulation being significantly higher (p< .01) than both asymmetrical and symmetrical (M
unilateral
= .34;
M
asymmetrical
= .20; M
symmetrical
= .19, respectively,). There were also significant differences between the co‐regulation
categories in the triadic context (F(2, 78) = 10.07, p< .01, η
2partial
= .23). Specifically, symmetrical was significantly
(p< .01) higher (M
symmetrical
= .36) than unilateral (M
unilateral
= .25), with no significant differences (p> .05) with respect
to asymmetrical (M
asymmetrical
= .30), and no significant differences between asymmetrical and unilateral.
Then at 6 months, there were also significant differences in the co‐regulation patterns in the dyadic context (F(2,
78) = 48.72, p< .01, η
2partial
= .55), with unilateral co‐regulation (M
unilateral
= .40) significantly (p< .01) higher than both
TABLE 2 Descriptive statistics (means and standard deviations) for all co‐regulation codes in dyadic and triadic condition
at 4 and 6 months of age
Dyadic Triadic
4th 6th 4th 6th
MSDMSDMSDMSD
Unilateral .34 .19 .40 .19 .25 .19 .37 .19
Following .12 .10 .15 .11 .19 .18 .30 .16
Initiating .19 .13 .22 .13 .06 .07 .07 .08
Demanding .02 .09 .03 .12 .00 .00 .00 .01
Symmetrical .19 .15 .23 .15 .35 .22 .39 .19
Accepting .01 .03 .02 .03 .27 .23 .23 .15
Innovating .18 .15 .21 .14 .08 .12 .16 .16
Resonant .00 .00 .00 .02 .00 .01 .00 .02
Asymmetrical .20 .15 .13 .10 .30 .22 .12 .10
Demonstrating .20 .15 .13 .09 .28 .21 .11 .09
Expecting .00 .01 .00 .01 .01 .02 .01 .02
Disruption .01 .02 .00 .01 .02 .03 .03 .05
Unengaged .00 .00 .00 .00 .00 .00 .00 .00
No code .26 .13 .24 .13 .08 .10 .09 .08
AURELI ET AL.7of14
asymmetrical (M
asymmetrical
= .13) and symmetrical (M
symmetrical
= .23), and symmetrical co‐regulation significantly
(p< .01) higher than asymmetrical. Finally, in the triadic context, there were also significant differences among the
co‐regulation categories (F(2, 78) = 106.02, p< .01, η
2partial
= .73), although in this case they were characterized by
the following pattern: the symmetrical and unilateral proportional durations were statistically not different (p> .05)
from each other (M
symmetrical
= .39; M
unilateral
= .38, respectively), but both categories were significantly (p< .01) higher
than asymmetrical (M
asymmetrical
= .12).
As expected, there were no significant correlations between ages for the proportional durations of any of the
co‐regulation patterns.
3.1.2 |Sub‐codes
We first analysed the unilateral pattern. As in a previous study (Hsu & Fogel, 2003), the active agent in all of the
instances of unilateral communication was the mother, so the initiating and following sub‐codes refer to the maternal
role. We performed a 2 (age points) × 2 (conditions) × 2 (co‐regulation) repeated measures ANOVA. The main effect of
co‐regulation was significant (F(1,79) = 26.65, p< .01, η
2partial
= .25) as well as that of conditions (F(1,79) = 9.89,
p< .01, η
2partial
= .11) and time (F(1,79) = 22.19, p< .01, η
2partial
= .22).
Turning to the two‐way interaction effects, the time by condition interaction effect was significant (F(1,79) = 4.37,
p= .04, η
2partial
= .05), and also the interaction between time by co‐regulation (F(1,79) = 8.68, p< .01, η
2partial
= .10) and
the interaction between conditions and co‐regulation (F(1,79) = 171.68, p< .01, η
2partial
= .68). Finally also the three‐way
interaction was significant (F(1,79) = 6.99, p= .01, η
2partial
= .08; see Figure 2). By decomposing the three‐way interac-
tion using simple effects analysis, at 4 months the two unilateral sub‐codes differed significantly in the dyadic context
(F(1, 79) = 21.43, p< .01, η
2partial
= 0.21), with the proportional duration of episodes in which the mother followed the
infant's attention showing significantly lower proportional durations (p< .01) than that of episodes in which the mother
attempted to initiate a communicative exchange by redirecting the infant's attention (M
following
= .13, M
initiating
= .19,
respectively). In the triadic context, the contrary was true, with the mother following significantly higher than the
mother initiating (M
following
= .19, M
initiating
= .06, respectively), F(1, 79) = 36.72, p< .01, η
2partial
= .317.
The same pattern of data was found at 6 months, with significant differences between unilateral sub‐codes in the
dyadic context (F(1, 79) = 16.35, p< .01, η
2partial
= .17). Here, mother following showed a lower (p< .01) proportional
duration than mother initiating (M
following
= .15, M
initiating
= .22), while in the triadic context this pattern was reversed
(F(1, 79) = 161.64, p< .01, η
2partial
= .67), with proportional durations higher for mother following than for mother
initiating (M
following
= .30, M
initiating
= .07).
For symmetrical co‐regulation, Infant Accepting was absent in the dyadic context at 4 months for about 68.8% of
the participants (N= 55), and at 6 months for about 57.5% (N= 46). Therefore, comparisons between the two
sub‐codes were computed in a 2 (Time) × 2 (Co‐regulation) ANOVA design only for the triadic context. Both main
FIGURE 1 Unilateral, asymmetrical, and symmetrical co‐regulation in dyadic and triadic contexts at 4 and 6 months of age
8of14 AURELI ET AL.
effects of Time (F(1,79) = 8.25, p< .01, η
2partial
= .09) and co‐regulation (F(1,79) = 48.70, p< .01, η
2partial
= .38) were
significant. The two‐way interaction was significant, F(1, 79) = 8.02, p< .01, η
2partial
= .09 (see Figure 3). In particular,
simple effects analysis showed that the proportional duration of episodes in which the infants accepted their mother's
offer was significantly higher than that of episodes in which the infants also innovated (M
accepting
= .27, M
innovating
= .08),
both at 4 months (F(1, 79) = 40.10, p< .01, η
2partial
= .34) and at 6 months (M
accepting
= .23, M
innovating
= .16; F(1,
79) = 10.46, p< .01, η
2partial
= .12). However, infant accepting was similar between the two ages (F(1, 79) = .67,
p= .41, η
2partial
= .01), whereas infant innovating was significantly higher at 6 months than 4 months (F(1,
79) = 14.81, p< .01, η
2partial
= .16).
3.2 |Temperament and co‐regulation
With the controlling of the nominal alpha for the number of correlations (Bonferroni corrections), there was only one
significant value: in the triadic context at 6 months, Soothability was positively correlated with Symmetrical co‐regu-
lation, rho = .36, p< .002 (see Table 3 for all correlations).
4|DISCUSSION
The present study examined mother–infant co‐regulation in face‐to‐face and with objects interactions. The dyads
were observed longitudinally at 4 and 6 months of age, in a developmental period where the infant involvement in
purely dyadic exchanges with the mother decreases in favour of interest in engaging with the external reality. As
FIGURE 2 Mother initiating and mother following in dyadic and triadic contexts at 4 and 6 months of age
FIGURE 3 Infant accepting and infant innovating in triadic contexts at 4 and 6 months of age
AURELI ET AL.9of14
previous studies on co‐regulation in this age period have only focused on the face‐to‐face context, the present study
aimed to fill the gap by presenting the dyads also with a context that included objects. We asked whether and how
co‐regulation patterns would be influenced by the interactive context. As the infant's individual dispositions proved
to be important in the early communicative episodes, the temperament dimensions were also considered.
Mothers and infants interacting in face‐to‐face (dyadic condition) and with toys (triadic condition) spent their time
in the three co‐regulation patterns that have already been identified as the most recurrent ones during the first
6 months of age (Evans & Porter, 2009; Hsu & Fogel, 2003; Silvén, 2001): unilateral, with the mothers actively
monitoring their inattentive infants; asymmetrical, with the infants paying attention to the mother's actions without
actively participating; and symmetrical, with both the mother and infant mutually engaging in a common activity.
The proportional durations of each pattern differed between the two conditions and over time. We found that in
the dyadic condition at 4 months, the unilateral pattern largely prevailed over both the asymmetrical and symmetrical
patterns, whereas in the triadic condition, the unilateral pattern was lower than the other two. This result is consistent
with Hsu and Fogel (2003) and Silvén (2001) who previously showed that unilateral co‐regulation takes up most of the
time in face‐to‐face interactions in the first few months of life. As a new result, we found that the predominance of
the unilateral pattern was limited to the dyadic condition, while in the triadic condition, symmetrical communication
prevailed. Therefore, the opportunity at 4 months to have the mother and the object available in the same context
helped the dyads to spend more time in interactions than the face‐to‐face situation allows.
This opportunity continues to favour mutual engagement in triadic interactions at the later age, as symmetrical
co‐regulation at 6 months was still higher in the triadic than the dyadic context, where unilateral continued to be
the prevalent pattern. However, the significant predominance of the symmetrical over unilateral in the triadic context
that had appeared 2 months before disappeared at 6 months, due to the upsurge of the unilateral, which increased
sharply at the expense of the asymmetrical. To recall, in the asymmetrical state, the two partners attend to a common
focus, with the infant watching the mother's activity without acting; while in the unilateral state, only the mother is
attending to the infant, who attends to only its own activity. Both the increase in the unilateral pattern and the
decrease in the asymmetrical pattern might relate to the concurrent changes in the motor domain. The infant manip-
ulative skills also improve strongly in this developmental period (Soska & Adolph, 2014), due to the infant mastering
reaching and grasping abilities, together with the gains in postural control. Therefore, the infant engagement with the
physical environment develops in more intensive and various ways at 6 months than previously. Due to this change,
we can suppose that, whereas the poor manipulative skills prevented the 4‐month‐old infants from being actively
engaged with the objects, the improvement in these skills in the following 2 months allowed the 6‐month‐old infants
to be more able to act on the objects. This advance might favour the infant transition from being a passive onlooker of
the mother's activity to being an active agent, thus increasing the time spent in manipulating objects independently, as
in unilateral co‐regulation. Conversely, the time spent in only observing the object manipulated by the mother, as in
TABLE 3 Spearman correlations between temperament dimensions at 4 months of age and co‐regulation patterns in
dyadic and triadic contexts at 4 and 6 months
Dyadic Triadic
Unilateral Symmetrical Asymmetrical Unilateral Symmetrical Asymmetrical
4th 6th 4th 6th 4th 6th 4th 6th 4th 6th 4th 6th
Duration of orienting .02 .05 .03 −.19 −.08 −.04 −.00 −.03 .04 .10 −.06 ‐.09
Low intensity Pleasure −.01 −.07 −.10 .04 .23 −.04 −.04 −.16 .08 .15 −.06 .12
Soothability −.13 −.18 −.18 .14 .27 .02 .01 −.30 .06 .36* −.02 .03
Cuddling −.07 −.13 −.15 −.05 .16 −.04 −.09 −.24 .16 .18 −.03 .05
Perceptive sensibility −.05 −.02 .03 .03 .18 −.06 .18 −.11 .12 .09 −.20 .01
Note. N = 80.
*Bonferroni corrected alpha‐p< .002.
10 of 14 AURELI ET AL.
asymmetrical co‐regulation, decreased. Interestingly, symmetrical co‐regulation did not decrease, as it was as high as
unilateral co‐regulation, which suggests that the infant interest in acting on the object independently accompanies the
interest in acting with the mother.
This result is in accordance with previous studies, which showed some relationships between motor and social
domains at an early age. As in Clearfield (2011), advances in social interactions in the age period immediately followed
the onset of upright locomotion and, according to Sommerville, Woodward, and Needham (2005), 3‐month‐old
infants who were able to act on objects exhibited an altered perception of the mother's actions. More recently and
of particular interest for the present study, Libertus and Needham (2011) found that the improvement in the infant's
attention to the mother's face accompanied the onset of reaching, which suggests that the infant's advances in dealing
with objects does not preclude an interest in other people. Indeed, as observed by de Barbaro et al. (2013), the two
domains begin to integrate into daily life by virtue of the infant's involvement in triadic contexts.
Results from the analysis of the sub‐codes further detailed the co‐regulation dynamics. For unilateral episodes,
the initiatives of the mother to attract and redirect the attention of the infant towards her face prevailed under the
dyadic condition. Maybe the mothers recognized the lower interest of the infant in being engaged with them, and
actively intervened in the face‐to‐face context to make the interaction occur. When the toys were available, the fol-
lowing role prevailed, with the mothers simply monitoring and supporting the infant's activity. It might be that the
mothers took the infant's increasing interest in the objects into account, and refrained from intervening, to leave their
infants free to play with the toys. If so, the mothers behaved in opposite ways to adapt to the infant's current
resources in each context. As the proportional duration of mother following behaviour was significantly higher at
6 months compared to 2 months before, the mothers showed to adapt to their infant's increasing developmental level,
by increasing the opportunity for the infant to act on the objects independently, according to the infant's growing
skills. Altogether, these results confirm the mother's sensitivity to infant functioning as the key feature of the parental
attitude (Kochanska & Aksan, 2004).
With respect to the sub‐codes of symmetrical pattern, the infant role as an innovating partner—who brings
something new to the interaction—was higher in the dyadic than triadic context. This is consistent with a huge
amount of research (as an example, see Als, Tronick, & Brazelton, 1979; Cohn & Tronick, 1987) that has shown
that infants participate actively in dyadic exchanges by reciprocating the other's moves with a wide repertoire
of expressive signals at facial, vocal, and body levels. Under the triadic condition, the passive role prevailed at both
4 and 6 months, with the infant responses to the mother's bids being limited to accepting her offers instead of
elaborating on them. However, a process leading the infant to have a more active role in that condition can be
detected, as the proportional duration of episodes in which the infants were capable of innovating the content
of social exchanges significantly increased at 6 months with respect to 2 months before. The improvement in
manipulative skills in this period would explain these results, as it might allow the infants to manage object‐medi-
ated social exchanges in a more creative manner than previously. If so, the influence of the motor domain on the
communicative domain we saw before—unilateral co‐regulation was higher at 6 months compared to 4 months—
would extend to symmetrical co‐regulation, by favouring in this case a higher quality of infant participation to
the triadic interaction as a creative partner.
With respect to the second aim, stability in co‐regulation was not seen, as the proportional durations of all of the
patterns did not correlate significantly between the two ages. This evidence is consistent with Hsu and Fogel (2003),
who showed that co‐regulation is affected by the immediately preceding pattern more than by the previous experi-
ence. It also suggests that the quality of the co‐regulation cannot be considered as a particular and enduring style
of a given dyad, but as a result of the current interaction. If so, the view of Fogel (1993, 2000) on co‐regulation as
a self‐organizing phenomenon, which cannot be understood beyond the situational specificity of its occurrence,
would be supported.
Finally, according to the literature on relationships between infant temperament and early social interactions, we
found that the more regulated infants were also higher in the symmetrical pattern. In the correlation of the infant
scores at 4 months with co‐regulation patterns at 4 and 6 months, only one significant value emerged: the
AURELI ET AL.11 of 14
symmetrical pattern positively correlated with the Soothability dimension under the triadic condition at 6 months. The
high specificity of the relation between the regulatory dimension of temperament and co‐regulation at this age makes
sense, because this dimension refers to a reduction in infant fussing, crying, or distress when soothing techniques are
used by the caregiver. As being actively involved in triadic interactions might be a new and perhaps challenging expe-
rience for infants aged 6 months, being easier to overcome distress would help the more soothable infants to join this
experience better than their less soothable peers.
5|CONCLUSIONS
To the best of our knowledge, the present study is the first to investigate mother–infant co‐regulation in face‐to‐face
and with toys interactions at 4 and 6 months. Studies to date have focused on either the former or the latter situation,
depending on the age period that was chosen for the observing: under face‐to‐face conditions when the infants were
in the first half of their first year of life, or with toys when the infants were in the second half.
The limitations of this study are indicated by the lack of an intensive longitudinal design, which prevents the
study from detailing the passage from 4 to 6 months of age as a continuous process. Moreover, independent
measures related to the mother, such as sensitivity or mind‐mindedness, and to the infant, such as motor abilities,
would have been useful to better understand the complexity of the co‐regulation as a multidimensional process.
These limitations notwithstanding, the results we have obtained add to our understanding of early communicative
development. In particular, they shed light on a process (i.e., involvement of the infant in triadic interactions at an
early age) that has been poorly investigated to date. In general, through the comparison of co‐regulation in dyadic
and triadic interactions, this study has contributed to support a context‐based and relational view of infant
development.
ORCID
Tiziana Aureli http://orcid.org/0000-0002-8584-0230
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How to cite this article: Aureli T, Presaghi F, Garito MC. Mother–infant co‐regulation in dyadic and triadic
contexts at 4 and 6 months of age. Inf Child Dev. 2017;e2072. https://doi.org/10.1002/icd.2072
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