Culture Carrying and Communication
Culture Carrying and Communication
Culture Carrying and Communication
Culture, carrying, and communication: Beliefs and behavior associated with babywearing
Emily E. Little
Cristine H. Legare
Leslie J. Carver
1
Abstract
maternal responsiveness to infant cues, yet it is unclear whether this responsiveness is driven by
the act of physical contact or by underlying beliefs about responsiveness. We examine beliefs and
behavior associated with infant carrying (i.e., babywearing) among U.S. mothers and
response to infant cues than non-babywearing mothers during an in-lab play session. In Study 2
in the lab using a within-subjects design and found that babywearing increased maternal tactile
interaction, decreased maternal and infant object contact, and increased maternal responsiveness
to infant vocalizations. Our results motivate further research examining how culturally-mediated
infant carrying practices shape the infant’s early social environment and subsequent
development.
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Culture, carrying, and communication: Beliefs and behavior associated with
babywearing
Human infants are born in an altricial state of dependence that is unique among primates,
making how mothers – and others – respond to cues critical for neonatal survival (Hrdy, 2011).
with a range of benefits for infant development (Ainsworth, 1978; Bornstein et al., 1992; De Wolff
& Van Ijzendoorn, 1997). Ethnographic accounts of infant care show that mother-infant physical
with high levels of maternal responsiveness (Barr, Konner, Bakeman & Adamson, 1991; Caudill
& Schooler, 1973; Hewlett et al., 1998; Mesman et al., 2017). Yet the role of physical contact in
maternal responsiveness has not been tested among U.S. populations, where the majority of
developmental research has been conducted (Nielsen et al., 2017). Here, we test the hypothesis
that mother-infant physical contact facilitates increased maternal responsiveness to infant cues.
We examine both the behavior (Study 1) and beliefs (Study 2) associated with babywearing, a
practice that emphasizes mother-infant physical contact by using slings, wraps, or structured
carriers to maintain physical contact with infants through hands-free carrying. We also measure
within-subject differences in maternal responsiveness when mothers and infants are in physical
contact versus not in physical contact by manipulating mother-infant physical contact in the lab
(Study 3).
Babywearing
Using tools to keep infants in close physical contact has a long history in human
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offspring are able to cling to mothers to maintain near-constant physical contact. Yet changes in
body hair, foot anatomy, upright posture, and post-natal maturity in humans are all associated
with the loss of the infant grasping ability (Tanner & Zihlman, 1976). This left human adults with
the energetic burden of having to carry infants in-arms. Transporting infants through in-arms
carrying is established as the most costly form of parental investment apart from breastfeeding
(Altmann & Samuels, 1992). This leads to an estimated metabolic cost increase of 500 kilocalories
per day (Gettler, 2010; Leonard & Robertson, 1995; Wall-Scheffler & Myers, 2008). Early hominids
may have developed tools to maintain close contact (e.g., cloth slings) to compensate for the high
energetic cost of using the arms to carry infants long distances during upright bipedal transit,
(Wall-Scheffler, Geiger, & Steudel-Numbers, 2007). The use of tools like slings makes carrying
more efficient and less strenuous than in-arms carrying, allowing adults to travel longer and
faster.
societies around the world (e.g., Mali, Dettwyler, 1988). Populations that engage in high levels of
mother-infant physical contact through babywearing and cosleeping (i.e., maintaining physical
contact throughout the night by bed-sharing) are characterized as proximal care cultures (Keller,
2002). This sustained physical contact throughout the day and night is proposed to have
implications for infant nutrition (e.g., Little, Legare, & Carver, 2018; McKenna & Gettler, 2016;
Pisacane et al., 2012) and direct skin-to-skin contact has well documented effects on maternal
health and infant development (e.g., Bigelow et al., 2012; Bigelow & Power, 2012; Moore et al.,
2012). Less is known about how carrying – without direct skin-to-skin contact – may shape
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respond contingently – in an anticipatory fashion – to infant cues (Barr, Konner, Bakeman &
Adamson, 1991; Caudill & Schooler, 1973; Hewlett et al., 1998; Mesman et al., 2017). Yet there are
very few studies documenting a connection between physical contact and maternal
Many cultures that practice proximal care also espouse parenting beliefs that emphasize
distress (e.g., Keller et al., 2009; Lamm & Keller, 2007). These beliefs are referred to as parental
ethnotheories, or cultural models used by parents to define their role as parents and their goals
for their children and families (Harkness & Super, 2006). Parental ethnotheories predict variation
in behavior both within and across populations (e.g., Harwood, Schoelmerich, Schulze, &
Gonzalez, 1999; Keller et al., 2004), including specific variation in maternal responsiveness
(Bornstein et al., 1992; Broesch et al., 2016; Kärtner et al., 2008; Kärtner, Keller, & Yovsi, 2010).
High levels of physical contact are associated with a set of beliefs about infancy that emphasize
not only the importance of maternal proximity, but also the need for immediate responses to
infant cues and breastfeeding as a strategy to minimize infant distress (e.g., Keller, 2002).
In the U.S. and other Western, industrialized societies, mother-infant interaction is most
often characterized as distal care (i.e., face-to-face interaction and object stimulation, Keller et al.,
2009). Infants spend the majority of their time in devices that limit physical contact with
caregivers, including cribs, strollers, car seats, playpens, bouncers, and swings (Maudlin, Sandlin,
& Thaller, 2012). Though babywearing is gaining popularity as an alternative to these bucket-like
devices, very little is known about maternal behavior and beliefs associated with this practice
among U.S. mothers. One study examined proximal care parenting among a Western population
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in the U.K., finding that infants of proximal care parents were carried more and cried less (St
James-Roberts et al., 2006). However, this has not been investigated specifically with babywearing
among U.S. mothers. It is unclear the extent to which mothers practicing babywearing in the U.S.
subscribe to the parenting beliefs traditionally associated with proximal care in non-Western
cultures. It is also an open question whether babywearing practices in the U.S. predict increased
Maternal responsiveness
maternal behavior occurring within 1-2 seconds of an infant cue (Broesch et al., 2016). Contingent
responsiveness shapes social learning (Bigelow & Birch, 1999), language acquisition (Nicely,
Tamis-LeMonda, & Bornstein, 1999; Tamis-LeMonda, Kuchirko, & Song, 2014), and attachment
formation (Ainsworth, Blehar, Waters, & Wall, 1978; Anisfeld, Casper, Nozyce, & Cunningham,
1990; Dunst & Kassow, 2008). Though developmental implications of maternal responsiveness
are well established, little research has investigated what predicts high levels of maternal
responsiveness.
A handful of studies have examined the connection between infant carrying and maternal
responsiveness among mothers in Western populations. Hunziker and Barr (1986) conducted a
randomized controlled trial of increased infant carrying, showing that infants in the experimental
group who were carried more cried significantly less than infants in the control group, which the
breastfeeding, mother-infant physical contact among dyads in the U.S. predicts increased
responsiveness to early infant hunger cues (Little, Legare, & Carver, 2018). Anisfeld and
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colleagues (1990) randomly assigned at-risk low-income parents to an infant carrying
intervention aimed to increase physical contact via babywearing. After three months of the
intervention, parents in the physical contact group were more vocally responsive to their infants
during a play session. At 12 months, the infants in the experimental group were more likely to be
securely attached to their caregivers, suggesting that the increased responsiveness caused by the
carrying intervention may have been driving the quality of the mother-infant relationship
Yet responsiveness is not expressed in the same way across cultural contexts. Mothers in
many proximal care cultures (e.g., Gussii mothers in Kenya, Richman et al., 1992; !Kung San
mothers in Botswana, Barr et al., 1991; Nso mothers in Camaroon, Kärtner et al., 2010) respond
more often to infant indications of discomfort rather than positive cues as a way to prevent overt
displays of distress. In contrast, typical mother-infant interaction in the U.S. (i.e., distal care
whether mothers in the U.S. who practice babywearing show patterns of responsiveness that are
similar in quality, modality, and valence to the responsiveness practiced by mothers in proximal
care contexts.
Current studies
In three studies, we examined the roles of mother-infant physical contact and maternal
beliefs in responsiveness to infant cues during dyadic social interaction. In Study 1, mothers and
their infants participated in a face-to-face play session in the lab, where we compared self-
infant positive and negative facial cues. We predicted that babywearing mothers would be more
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responsive to infant cues overall. Because the ethnographic literature documents that mothers in
proximal care cultures often respond more to negative than positive cues to minimize overt
mothers – would be more responsive to negative rather than positive infant cues. In Study 2, we
examined whether mothers who practiced babywearing have a set of parenting beliefs distinct
from non-babywearing mothers. We predicted that babywearing mothers would be more likely
to espouse beliefs typically associated with proximal care in non-Western cultures (e.g.,
lab with a within-subject comparison of maternal responsiveness to infant cues when wearing the
infant in a carrier and when in face-to-face contact (with no physical contact). We predicted that
mothers would show increased responsiveness when the infant was in the carrier.
Study 1
Our first objective in Study 1 was to examine whether the practice of babywearing
predicted differences in the contingency of maternal responses to infant cues. Mothers who
practiced babywearing as the primary method of transporting their infant (babywearers) and
mothers who did not practice babywearing (non-babywearers) participated in a face-to-face play
session in the lab where we measured overall contingent responsiveness to infant cues. In line
with past work (e.g., Anisfeld et al., 1990), we predicted that mothers who practiced babywearing
Our second objective was to test whether babywearing was associated with a difference
in the specific type of responsiveness, with regard to the valence of infant cues to which mothers
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responding to indications of infant discomfort as a way to mitigate infant distress (Keller et al.,
2009; Richman, Miller, & LeVine, 1992). Mothers in many proximal care cultures are more likely
to respond to negative versus positive infant cues as a way to address needs and minimize
distress rather than stimulating positive emotionality (e.g., Richman et al., 1992; Barr et al., 1991;
Kärtner et al., 2010). This is in stark contrast to mothers in the U.S. who go to great lengths to
highlight infant positive emotion and respond more enthusiastically to positive cues. Because of
predicted that increased physical contact might make mothers in the U.S. more similar to mothers
in proximal care culture and therefore more likely to respond to infant negative cues rather than
positive cues. We measured the proportion of infant positive cues versus negative cues to which
the mother responded. If mothers in the U.S. who practice babywearing are similar to mothers in
proximal care cultures, we would expect these mothers to be more likely to respond to infant
Our third objective was to assess differences in infant behavior between infants of
interaction, it is difficult to make conclusions about physical contact and maternal responsiveness
without taking into account differences in infant behavior that may be indirectly influencing
maternal behavior. Here, we are able to document differences in both infant behavior and
Method
All procedures and recruitment methods were approved by the Institutional Review
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Participants. Twenty-three mothers and their infants (M = 9.25 months, SD = 2.16 months,
4.4- 11.93 months) participated in this study. Mothers were categorized as babywearers if they
identified babywearing as the primary means of transporting their infant. Mothers were
their infant. These dyads were recruited both from a subject list compiled from the San Diego
County Records Office and from social media recruitment within parenting groups.
Setup. Two FlipCam video cameras were setup with flexible GorillaPod tripods in the
experimental room to record the mother-infant interaction. One camera was positioned across
from the infant, to record the infant’s facial expressions, while the second camera was positioned
across from the mother’s face. The infant was positioned in a plastic play chair with a plastic tray.
There was a rubber play mat on the floor, and mothers were instructed to sit on the floor across
from the infant. Figure 1 shows the position of the mother and baby for both conditions.
Procedure. Mothers came into the lab with their infant where the study was explained to
them and written consent was obtained. Mothers used a written form to answer basic
demographic questions as well as the babywearing categorization question: “What is the primary
method you use to transport your baby?” Mothers could only choose one response (babywearing,
carrying, car seat, or stroller). Mothers were categorized as babywearers if their response to this
question was babywearing. For the play session, mothers were positioned face-to-face across
from their infant, who was sitting in a play chair with a tray. Mothers were told to play with their
infant however they wanted for two minutes. No toys were provided. The experimenter pressed
record on the two video cameras than left the room during the play session while mother and
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Coding. The videotaped interaction was coded for infant displays of positive and negative
affect, infant gaze, and maternal contingent responses to infants’ positive and negative cues.
Mothers were measured on the overall proportion of infant cues to which they responded
contingently, as well as the valence of infant cues to which they responded (i.e., proportion of the
infant’s positive cues to which they responded, proportion of the infant’s negative cues to which
they responded). For the behavioral outcome measures, coding was completed by two coders –
blind to the hypotheses of the study – through the use of ELAN, video annotation software
developed by the Max Planck Institute for Psycholinguistics (Lausberg & Sloetjes, 2009). The
coding software allowed for the documentation of the exact start time and end time of each
behavior, providing a measure of total frequency and duration of each behavior. Coders first
documented the total duration of each infant behavior (positive affect, negative affect, gaze),
spending one pass through the video for each behavior. Maternal responsiveness was coded by
going back through the video and for each instance of infant positive or negative affect, looking
at the one-second window after the behavior to see if the mother’s infant-directed behavior
changed. The coders completed the first 20% of the participant videos together and any
discrepancies were discussed until coders achieved frame-by-frame agreement. All subsequent
mother’s infant-directed behavior changed within the one-second window after an infant display
of positive or negative affect (e.g., baby smiled and mom smiled, baby frowned and mom
vocalized). This temporal window is consistent (e.g., Broesch et al., 2016) or even more
conservative (e.g., Anisfeld et al., 1990) than past work in the literature on maternal
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responsiveness. For each participant, we calculated total proportion of cues to which the mother
responded (total maternal responses divided by total occurrences of infant positive or negative
affect).
which the mother responded within a one-second window. For each mother, we calculated the
proportion of the infant’s positive cues to which she responded (total maternal responses to infant
negative cues to which the mother responded within a one-second window. For each mother, we
calculated the proportion of the infant’s negative cues to which she responded (total maternal
responses to infant negative affect divided by total occurrences infant negative affect).
Infant positive affect. Positive affect was coded whenever the infant smiled or laughed.
A smile was defined as the corners of the infant’s mouth being turned upward, with the mouth
being either open or closed. For each infant, we calculated the total number of occurrences and
total duration (in seconds) during which the baby displayed positive affect.
Infant negative affect. Negative affect was coded whenever the infant frowned, grimaced,
or cried. A frown was defined as the corners of the infant’s mouth being turned downward, with
the mouth being either open or closed. For each infant, we calculated the total number of
occurrences and total duration (in seconds) during which the baby displayed negative affect.
Infant gaze. To assess the level of social engagement across the two groups, we measured
infant gaze as anytime the infant was looking at the mother’s face (irrespective of whether the
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mother was currently looking at the infant). For each infant, we calculated the total number of
occurrences and total duration (in seconds) during which the baby gazed at the mother.
Results
Fourteen of the mothers were categorized as babywearers and nine of the mothers were
months, SE = .59 months) and the non-babywearers (M = 9.47, SE = .74) with regard to infant age,
Analyses. To test the prediction that babywearing mothers would show increased
responsiveness to infant cues, we conducted Analysis of Variance (ANOVA) tests for each of the
dependent measures of infant behavior and maternal responsiveness, with group (babywearing
Collapsing across the two physical contact groups, infant age was not predictive of infant
positive affect, infant negative affect, infant gaze, maternal responsiveness to positive cues,
maternal responsiveness to negative cues, or overall maternal responsiveness (all ps > .1).
babywearers (M = .84, SE = .05) and the non-babywearers (M = .62, SE = .07) with regard to overall
proportion of the infant cues to which the mother responded, F (1, 21) = 5.48, p = .03, h2= .22, see
Figure 2.
Maternal responsiveness to positive cues. There was a significant difference between the
babywearers (M = .82, SE = .07) and the non-babywearers (M = .57, SE = .08) with regard to
proportion of the infant positive cues to which the mother responded, F (1, 21) = 5.13, p = .03, h2 =
.20.
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Maternal responsiveness to negative cues. There was no difference between the
babywearers (M = .83, SE = .12) and the non-babywearers (M = .59, SE = .15) with regard to
proportion of the infant negative cues to which the mother responded, F (1, 12) = 1.56, p = .24, h2
= .12.
Infant positive affect. There was no significant difference between the babywearers (M =
24.14 seconds, SE = 3.42) and the non-babywearers (M = 19.40 seconds, SE = 4.27) with regard to
Infant negative affect. There was no difference between the babywearers (M = 11.27
seconds, SE = 5.87) and the non-babywearers (M = 8.05 seconds, SE = 5.87) with regard to duration
Infant gaze. There was no difference between the babywearers (M = 39.41 seconds, SE =
7.19) and the non-babywearers (M = 26.72 seconds, SE = 8.96) with regard to duration of infant
Discussion
This study examined whether long-term experience with mother-infant physical contact
to-face mother-infant play paradigm. Our first finding was in line with our predictions:
babywearing mothers were more contingently responsive to infant cues than mothers who did
not practice babywearing. This result is consistent with past research showing mothers were more
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In contrast to our predictions, babywearing mothers were more likely to respond to
positive cues than non-babywearing mothers, but this group difference was not seen with regard
to maternal responses to infant negative cues. Given that responsiveness in proximal care cultures
(Keller et al., 2009; Richman, Miller, & LeVine, 1992), we predicted that increased physical contact
might make mothers in the U.S. more likely to respond to negative cues. As we see here, however,
it may be that positive affect is valued and emphasized to such a high degree in U.S. culture that
parenting goals.
Our data showed no differences in infant positive affect, negative affect, or gaze across
the two groups. Given that mother-infant interaction is a reciprocal and bidirectional process, one
possibility is that experience with babywearing influences maternal interaction behavior by first
causing a change in the infant. In this study, there were no differences in infant behavior across
the two groups, suggesting that long-term experience with mother-infant physical contact may
be affecting maternal responsiveness directly, rather than via a change in infant communication.
The primary limitation of the study was the small sample size and the fact that mothers
were not randomly assigned to groups. It is possible that the increased responsiveness could be
attributed to the experience with physical contact, but it is just as likely that the increased
responsiveness could be explained by differences in maternal beliefs associated with the practice
of babywearing. For example, mothers may be more likely to practice babywearing if they
support a certain (i.e., responsive) approach to infant care. Ethnographic studies conducted in
small-scale societies outside of the U.S. demonstrate that the practice of babywearing is closely
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tied to a distinct set of maternal beliefs about infant care and maternal responsiveness, yet no
study has evaluated the degree to which U.S. babywearing mothers subscribe to these beliefs. In
Study 2, we evaluated whether mothers who practice babywearing in the U.S. espouse a
results of Study 1. We used a maternal questionnaire (Keller, 2002, see Table 1) to assess whether
babywearing predicts increased alignment with the values of proximal care culture.
Study 2
Parenting behavior is associated with variation in beliefs about infant care (e.g., Bornstein,
Cote, & Venuti, 2001; Broesch et al., 2016; Hewlett & Lamb, 2002; Lamm & Keller, 2007; Shwalb,
Shwalb, & Shoji, 1996). The connection between experience with physical contact and increased
beliefs, rather than the practice of babywearing. Practices in the U.S. that facilitate increased
infant care (e.g., Attachment Parenting, Granju & Kennedy, 1999; Sears & Sears, 2001). Yet
differences in actual parenting beliefs associated with proximal care practices have not been
documented systematically among U.S. parents. The aim of Study 2 was to measure parenting
Method
All procedures and recruitment methods were approved by the Institutional Review
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Participants. We recruited mothers (N = 492) of newborn to 12-month-old infants to fill
out an online questionnaire. These dyads were recruited from social media postings within U.S.-
based parenting groups. Mothers were 20-45 years of age (M= 30.85, SD = 4.49) and infants ranged
from .23 months to 12.98 months (M = 6.43, SD = 3.47). Mothers had completed an average of 16.09
years of schooling (SD = 2.61, 10-25 years). A little over half of the mothers were currently not
working (55.19%) and were multiparous (i.e., had more than one child, 68.11%). About half of the
(administered through the Google Forms platform) which assessed demographic factors,
Breastfeeding status. Given that breastfeeding is closely tied to the beliefs and practices of
proximal care cultures, we asked mothers about their current feeding method (exclusive
asked about general use of babywearing as the primary transport method (in comparison with
arm carrying or stroller use), as well as variation in the intensity of babywearing (e.g., hours per
day spent babywearing, infant age at babywearing initiation). We also measured motivation for
babywearing.
Maternal beliefs. To assess parenting beliefs, mothers were asked about their agreement or
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components of maternal behavior toward a 3-month-old infant. This instrument has been used
globally to assess the degree of alignment with proximal care versus distal care parenting goals
(Keller, 2002, see Table 1). Responses to each question were on a scale from one (completely
disagree) to five (completely agree). Responses from each participant were compiled to form a
proximal care belief score, calculated by summing responses from all questions aimed to measure
alignment with goals of proximal care parenting culture then subtracting the sum of responses to
all questions designed to test alignment with goals of distal care parenting culture. The range of
possible scores was negative 20 to positive 20. Any positive score indicated that mothers leaned
more toward the values of proximal care culture than distal care culture, and a higher score
indicated a greater agreement with the parenting goals characteristic of proximal care culture.
Procedure. After mothers expressed interest in participating in the study, they were
contacted electronically by a research assistant who explained the study and obtained consent.
Participants filled out the online questionnaire from their home, administered through the Google
Forms platform.
Results
Many mothers reported babywearing as their primary infant transport method (72.82%)
with the other mothers choosing in-arms carrying (15.92%) and strollers/seats (11.25%). Mothers
reported initiating babywearing at age zero to six months (M = .41, SD = 1.01) and reported
babywearing for an average of 2.61 hours per day (SD = 2.44, 0-15 hours).
Analyses. We first conducted a linear regression to predict maternal beliefs (i.e., degree
of alignment with proximal care culture) from babywearing (versus arms carrying and stroller
use), babywearing intensity (hours per week and age of initiation), and babywearing motivation.
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We next tested these effects while controlling for potential confounds by including fixed effects
for infant age, maternal age, maternal education, employment, parity, and breastfeeding status.
Babywearing (in comparison with strollers) was predictive of a higher overall proximal
care belief score, b = 1.643, SE = .399, t = 4.11, p < .0001, and arm carrying was not, b = 0.371, SE =
.519, t = 0.71, p = .475. Mothers who practiced babywearing had a higher proximal care belief score
(M = 6.637, SE = .309) than mothers who reported carrying in arms (M = 5.36, SE = .651) or mothers
There was also an effect of babywearing intensity. Age of initiation of babywearing (in
months) was negatively associated with proximal care belief score, b = -0.659, SE = .276, t = -2.39,
p = .017, such that mothers who had started wearing their infant later in development had a lower
proximal care belief score. Hours per day spent babywearing was predictive of a higher proximal
Reason for babywearing was predictive of proximal care belief score, F (4, 433) = 3.705, p
associated with proximal care belief score, b = 3.258, SE = 1.623, t = -2.01, p = .045. Mothers who
reported babywearing for convenience had a lower proximal care belief score (M = 5.234, SE =
.348) than mothers who practiced babywearing for social or cultural reasons (M = 16, SE = 5.621),
for bonding (M = 6.6.21, SE = .554), or for health and development (M = 7.603, SE = .681).
In the multivariate model controlling for infant age, maternal age, maternal education,
employment, parity, and breastfeeding status, babywearing (versus strollers) was still
significantly predictive of a higher proximal care belief score, b = 1.098, SE = 0.433, t = 2.54, p =
.012, while arm carrying was not, b = 1.098, SE = .433, t = 1.22, p = .222.
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Discussion
The aim of this study was to assess the relationship between babywearing practices and
proximal care parenting beliefs among U.S. mothers. Proximal care beliefs have thus far primarily
been used to describe parenting beliefs and practices outside of Western populations, but
show that babywearing mothers were more likely to espouse parenting beliefs characteristic of
proximal care culture. Proximal care parenting beliefs were predicted specifically by age of
initiation of babywearing and frequency of this practice in hours per day. Given that U.S.
parenting generally aligns with distal care beliefs and practices, these data suggest that
babywearing may be more than simply a parenting practice, but rather a central component of a
possibility is that the act of physical contact itself directly facilitates an immediate increase in
responsiveness to infant cues, independent of maternal beliefs. To test this possibility, Study 3
manipulated mother-infant physical contact in the lab to measure the immediate effect of physical
Study 3
Longitudinal studies have shown a long-term effect of infant carrying and direct skin-to-
skin contact on maternal responsiveness (e.g., Anisfeld et al., 1990), yet the length of these
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experimentally test whether immediate physical contact facilitated increased maternal
responsiveness. Mothers were asked to play naturally with their infant in two conditions
(physical contact, no physical contact) that were designed to manipulate amount of mother-infant
physical contact. In one condition, the infant was positioned in an infant carrier strapped to the
mother face-in (physical contact) and in the other condition the infant was positioned face-to-face
sitting in a high chair (no physical contact). As mothers and infants were in face-to-face contact
for both conditions, amount of visual contact was held constant to isolate the potential effect of
The first objective was to test the immediate effect of mother-infant physical contact on
maternal vocalizations occurring within one second of an infant’s vocalization (Broesch et al.,
2016). Because infants being strapped to the mother’s chest in a carrier made it difficult to measure
facial expressions in the physical contact condition, vocalization was a more viable measure of
responsiveness in this study. We predicted that mothers would be more vocally responsive to
their infant when in immediate physical contact in comparison to when not in physical contact.
Our second objective was to measure differences in maternal and infant behavior between
the two conditions. To examine the broader context of mother-infant interaction, we also
measured differences in maternal and infant vocalizations, touch, and object contact between the
physical contact condition and the no physical contact condition. Most previous work suggesting
has been done across cultures, consistently showing that mother-infant physical contact is
associated with increased interaction in the tactile modality (e.g., Little, Carver & Legare, 2016)
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and decreased vocal and object-based interaction (e.g., Keller et al., 2004). We predicted that
mothers would be more likely to interact with infants using touch (tactile interaction) in the
physical contact condition and would be more likely to interact using vocal communication and
Method
All procedures and recruitment methods were approved by the Institutional Review
study (M = 5.62 months, 2.6-8.6 months, 11 female). Mothers had completed an average of 17.25
years of education (SD = 1.39 years, 15- 20 years). Mothers were White (84.21%) or
Hispanic/Latina (15.79%). Mothers were recruited from online social media postings to U.S.
parenting groups. During this single session study, mothers interacted with their infants in two
different conditions (physical contact, no physical contact), the order of which was
Setup. Two FlipCam video cameras were setup with flexible GorillaPod tripods in the
experimental room to record the mother-infant interaction. One camera was positioned across
from the infant, to record the infant’s facial expressions, while the second camera was positioned
across from the mother’s face. For the physical contact condition, infants were strapped to their
mother’s chest with a soft structured infant carrier. Mothers who had their own babywearing
carrier were permitted to use their own if they wanted (for comfort) as long as the carrier kept
the infant in a face-to-face, tummy-to-tummy position. For the no physical contact condition, the
infant was positioned in a plastic play chair with a plastic tray. There was a rubber play mat on
22
the floor, and mothers were instructed to sit on the floor across from the infant. Figure 1 shows
the position of the mother and baby for both conditions. For both conditions, there were simple
toys available to use in the room (squishy ball and stacking cups).
Procedure. After obtaining informed consent, the procedure was explained and mothers
were asked to provide information about the demographics of their household and infant
carrying and feeding practices. For both of the two within-subject conditions (physical contact,
no physical contact) mothers were told to play with their infant however they normally do while
they were videotaped for two minutes in a playroom alone. For the additional condition
(babywearing face-out), mothers were given the same instructions. The mother was not given
specific instructions as to whether or not she should use the toys that were provided.
vocalizations. Mothers and infants were also measured on their interaction behavior, scored for
the duration of vocalization, touch, and object contact during the play session. Coding was
completed by two independent coders – blind to the hypotheses of the study – through the use
of ELAN video annotation software developed by the Max Planck Institute for Psycholinguistics
(Lausberg & Sloetjes, 2009). The coding software allowed for the documentation of the exact start
time and end time of each behavior, providing a measure of total frequency and duration of each
behavior. Coders first documented the total duration of each infant and maternal behavior
(vocalization, touch, object contact), spending one pass through the video for each behavior.
Maternal responsiveness was coded by going back through the video and for each instance of
infant vocalization, determining whether the mother vocalized during the one-second window
following the infant’s vocalization. The coders completed the first 20% of the participant videos
23
together and any discrepancies were discussed until coders achieved frame-by-frame agreement.
Maternal and infant characteristics. We solicited information about infant age, maternal
age, maternal education, race/ethnicity, and income from all mothers to examine any associations
with maternal or infant behavior. We also asked mothers about current use of babywearing as
their primary transport method (versus strollers or car seats) and about current breastfeeding
status to assess whether the potential physiological bonding facilitated by breastfeeding may
have been underlying any differences in maternal or infant behavior. Maternal responsiveness.
Maternal responsiveness was coded as the number of occurrences of the mother vocalizing in
response to an infant vocalization (i.e., within a one-second window). This temporal window is
consistent (e.g., Broesch et al., 2016) or even more conservative (e.g., Anisfeld et al., 1990) than
Maternal vocalization. Vocalization was coded whenever the mother vocalized – either
verbal or non-verbal. All voluntary utterances were counted as vocalizations, while all sneezes,
burps, or other involuntary noises were not coded as vocalization. Each mother was scored on
the duration of time of vocalization during the play session of each condition.
Maternal touch. Maternal touch was coded whenever the mother touched the infant. All
voluntary physical contact was counted as tactile interaction, while all passive physical contact
(i.e., the inevitable physical contact of having the infant strapped to the mother in the physical
contact condition) were not coded as touch. Each mother was scored for duration of time touching
24
Maternal object contact. Any contact by the caregiver with one of the play objects – in the
context of the mother-infant interaction – was coded as object contact. Any contact by the mother
with an object that was out of sight of the infant (or unable to be felt by the infant) was not
included. Each mother was scored for duration of time in object contact during each condition.
Infant vocalization. Infant vocalization was coded whenever the infant vocalized. All
voluntary utterances were counted as vocalizations, while all sneezes, burps, or other involuntary
noises were not coded as vocalization. Each infant was scored on the duration of time spent
Infant touch. Infant touch was coded whenever the infant touched the mother (coding
separately for mother-initiated versus infant-initiated, depending on who initiated the touch). All
voluntary physical contact initiated by the infant and directed toward the mother was counted as
infant touch, while all passive physical contact (i.e., the inevitable physical contact of having the
infant strapped to the mother in the physical contact condition) were not coded as touch. Each
infant was scored on duration of time touching the mother during each condition.
Infant object contact. Infant object contact was coded as any contact with an object
initiated by the infant. Each infant was scored separately for duration of time in object contact
Results
Out of the twenty mothers that participated, twelve of the mothers were exclusively
breastfeeding, two were formula feeding and breastfeeding, five were breastfeeding and
complementary feeding (solids), and one was feeding with only formula. Though all mothers had
been recruited from a babywearing-specific social media group, five of the mothers reported that
25
they no longer used babywearing as their primary means of transporting their infant despite
maternal responsiveness and maternal and infant interaction behavior, we performed repeated
measures ANOVAs for each maternal and infant behavior of interest with condition (physical
Maternal and infant characteristics. In the no physical contact condition, infant age was
negatively associated with duration of infant touch, b = -.49, t = -2.36, p = .03, and positively
associated with duration of object contact, b = 15.51, t = 5.91, p = .02. Infant age was not predictive
of duration of infant vocalization in the no physical contact condition, b = .72, t = 2.06, p = .05.
Infant age was not associated with infant or maternal behavior in the physical contact condition
In the physical contact condition, maternal age was negatively associated with duration
of object contact, b = -3.34, t = -2.55, p = .02. Maternal age, maternal education, and ethnicity were
not associated with any other maternal or infant behaviors in the physical contact condition or
Breastfeeding status was not associated with any maternal or infant behaviors in the
physical contact condition or the no physical contact condition (all ps > .1).
maternal responsiveness, F (1, 19) = 5.37, p = .03, h2 = .67, such that mothers were more responsive
26
.76 vocalizations) than in the no physical contact condition contact (M = 2.15 contingent
the physical contact condition (M = 38.24 seconds, SE = 3.89) in comparison with the no physical
contact condition (M = 38.81 seconds, SE = 3.90), F (1, 19) = 0.01, p = .92, h2 = -0.07.
Maternal touch. There was a difference between conditions in duration of maternal touch,
F (1, 19) = 11.06, p = .004, h2 = .52, such that mothers touched their infants for longer in the physical
contact condition (M = 31.71 seconds, SE = 6.31) than in the no physical contact condition (M =
Maternal object contact. There was not a significant difference between the physical
contact condition (M = 24.39 seconds, SE = 6.69) and the no physical contact condition (M = 41.98
seconds, SE = 6.69) with regard to duration of maternal object contact, F (1, 19) = 3.74, p = .068, h2
= .21.
the physical contact condition (M = 3.62 seconds, SE = .73) in comparison with the no physical
contact condition (M = 2.32 seconds, SE = .73), F (1, 19) = 2.29, p = .15, h2 = .49.
Infant touch. There was no difference in duration of infant touch in the physical contact
condition (M = .63 seconds, SE = .41) in comparison with the no physical contact condition (M =
Infant object contact. There was a significant difference in duration of infant object
contact, F (1, 19) = 9.68, p = .006, h2 = .56, such that infants were in contact with objects for less time
27
in the physical contact condition (M = 25.44 seconds, SE = 9.28) than in the no physical contact
Discussion
measured the duration of maternal and infant vocalization, touch, and object contact when the
infant was being worn in a carrier versus sitting face-to-face with no physical contact. Consistent
with our predictions, maternal responsiveness increased when mothers and infants were in
physical contact in comparison when they were sitting across from each other. There was no effect
of physical contact on overall duration of maternal or infant vocalizations, confirming that the
increase in responsive maternal vocalizations in the physical contact condition was specific to
responsiveness rather than reflective of an overall increase in vocalizations. This result is aligned
with past work comparing triadic mother-infant interactions with objects in proximal care versus
distal care communities that found differences in mother-infant physical contact were not
associated with variation in vocalization (e.g., Little, Carver, & Legare, 2016). Though we can only
speak to one type of contingent maternal responsiveness from the results of Study 3 (i.e., maternal
language acquisition (Goldstein, Schwade, & Bornstein, 2009; Goldstein & Schwade, 2008; Gros-
Louis, West, & King, 2016; Tamis-LeMonda, Kuchirko, & Song, 2014).
modality of mother-infant interaction across the two conditions that warrant further attention.
28
Mothers engaged in more touch when in physical contact with their infant. This finding has
clinical significance. Not only are infants potentially benefitting from the long-term benefits of
sustained physical contact from being in a carrier that is suggested by past studies (e.g., Anisfeld
et al., 1990), but they are actually being exposed to a qualitatively different type of interaction
from mothers as soon as they are put in a babywearing carrier versus being put in a seat. There
was a difference in infant object contact across the two conditions, such that infants spent more
time in object contact when not in physical contact with their caregiver. This relative difference
in emphasis on object play aligns with observations of object contact in proximal care versus distal
care communities (Keller, 2002). Though most developmental research focuses on face-to-face
interaction and object play as central social environments for learning and development (Akhtar
& Gernsbacher, 2008), increasingly more research shows the benefits of physical contact and
tactile communication as being critical for developmental and physiological processes (e.g.,
Charpak et al., 2001; Chwo et al., 2002; Feldman, Eidelman, Sirota, & Weller, 2002; Ferber et al.,
2002). More research is needed to understand the developmental implications of these different
General Discussion
Mother-infant physical contact is the natural postnatal condition for primates (Bard, 2002)
and is associated with a range of benefits for both mother and offspring (e.g., Charpak et al., 2001;
Chwo et al., 2002; Feldman, Eidelman, Sirota, & Weller, 2002; Ferber et al., 2002). Yet the effects
of this physical contact on maternal behavior and beliefs are not well understood. Here, we tested
the prediction that mother-infant physical contact increases maternal responsiveness in U.S.
babywearing mothers. Below, we discuss the novelty of our findings and potential explanations,
29
limitations and recommendations for future research, and broader implications of this research
Explanations
sensitivity and responsiveness (Bigelow et al., 2014; Bigelow, Littlejohn, Bergman, & McDonald,
2010; Bystrova et al., 2009). Yet effects of physical contact via carrying without direct skin-to-skin
have been relatively neglected in the literature. We found that mothers who reported more
experience with mother-infant physical contact through babywearing were more likely to
respond contingently to infant cues than mothers with less experience with long-term physical
contact during a face-to-face in-lab play paradigm (Study 1). Babywearing mothers were more
likely to report agreement with parenting beliefs characteristic of proximal care cultures (Study
2). When testing the immediate effect of mother-infant physical contact, babywearing facilitated
increased maternal tactile interaction, decreased maternal and infant object contact, and increased
Proximal care has been primarily used to describe the parenting behavior of small-scale,
indigenous communities. However, a movement within many Western countries has led some
parents to choose to adopt a proximal care parenting style, despite infant care in Western
cultures having historically been characterized as distal care. Proximal care practices and beliefs
have many potential implications for infant health and development, yet until now have not
There are several explanations as to why physical contact facilitates increased maternal
responsiveness. One explanation is that the long-term experience with physical contact promotes
30
mother-infant bonding over time, increasing maternal motivation to attend to and respond to
infant cues. This explanation is supported by the findings of Study 1 showing that mothers with
more long term experience with physical contact were more likely to be responsive to infant cues
even when not in direct physical contact. This is also supported by the results of Study 2 showing
that mothers who practice babywearing are more likely to prioritize maternal responsiveness and
other goals of proximal care culture. One limitation of these two studies is that because they were
observational, we are unable to conclude whether physical contact changes maternal beliefs or
whether maternal beliefs motivate mothers to practice increased physical contact with infants.
Study 3 suggest that in addition to increasing maternal motivation to respond to infants, physical
contact also has a direct, immediate effect on responsiveness. This is potentially explained by the
closeness of the infants’ body allowing the mother to attend to cues that normally would have
Limitations
These studies had several limitations. In Study 1, the self-selection of mothers into the
babywearing group versus the non-babywearing group was problematic because it is very likely
that mothers who are more responsive in general would be more likely to seek out practices like
babywearing. Though the observed differences across the two groups in maternal responsiveness
are interesting and warrant future research, the small sample sizes and lack of random
assignment limit our ability to draw conclusions about the association of one parenting practice
(babywearing) with the observed differences in behavior. It is also difficult to generalize our
31
findings about mother-infant interaction, given that maternal and infant behavior was observed
for such a short time and under an artificial in-lab play environment. In Study 1 and Study 3,
more specific information about babywearing should have been solicited, including infant age at
babywearing onset, frequency of babywearing throughout the day, and position of babywearing.
Study 2 solicited more specific information about duration and motivation for babywearing, yet
There were also some broader limitations across all three studies, including a very small
sample size in Studies 1 and 3, as well as variation in infant age, both within and across studies.
Babywearing is also just one of many practices that facilitates physical contact between infants
and caregivers. Though we intentionally chose babywearing as a proxy for long-term physical
contact, many other forms of mother-infant physical contact (e.g., cosleeping, infant massage)
exist and may provide even more physical contact between infants and caregivers. In future
studies, if the effect of physical contact is the primary effect of interest, more comprehensive
information should be collected about all forms of physical contact. Another broad limitation of
this work is that only mother-infant interaction was examined, and only across a specific
population. In future work, it will be important to assess how physical contact relates to infant-
caregiver interaction more broadly as there are documented implications of father-infant physical
contact as well (e.g., Gettler, 2010; Gettler, Augustin, McDade, & Kuzawa, 2012).
Implications
32
facilitating word comprehension (Tamis-LeMonda, Kuchirko, & Song, 2014), which is
manipulations of maternal responsiveness in the lab show that infants produce more
sophisticated pre-linguistic sounds when mothers are more responsive to their vocalizations
(Goldstein, Schwade, & Bornstein, 2009; Goldstein & Schwade, 2008; Gros-Louis, West, & King,
2016) and the way parents respond to infant attention during object play is related to word
production (Stevens, Blake, Vitale, & MacDonald, 1998). In one study, contingent reactions (i.e.,
King, & West, 2003). All of these studies describe the behavior of mothers in Western, educated,
industrialized, rich, and democratic (“WEIRD”) societies (Arnett, 2008; Henrich, Heine, &
Norenzayan, 2010; Nielsen et al., 2017). Many factors including maternal education level
(Richman et al., 1992) and culture (Bornstein, Cote, & Venuti, 2001; Bornstein et al., 1992; Broesch
et al., 2016; Kärtner, Keller, & Yovsi, 2010) predict variation in maternal responsiveness.
transport method. Babywearing is a socialization tool, and the infant-caregiver physical contact
that this practice facilitates is equally as important as the visual cues (i.e., gaze) and auditory cues
(i.e., vocalizations) that are emphasized to a much greater degree in the developmental literature
(Akhtar & Gernsbacher, 2008). Our data demonstrate that babywearing is associated with
increased maternal responsiveness and beliefs associated with proximal care cultures. We also
show that physical contact facilitates immediate changes in maternal responsiveness and mother-
33
infant interaction. Given that the modality of interaction can have an influence on developmental
trajectories (e.g., Kärtner, Keller, & Yovsi, 2010), understanding the differences in the modality of
suggests mother-infant physical contact predicts high levels of maternal responsiveness to infant
cues, yet this had not previously been investigated within Western populations. Our data suggest
that babywearing among U.S. mothers may play a role in maternal responsiveness, an important
component of the infant’s early social environment. We hope these studies motivate further
research on the short- and long-term effects of infant carrying practices on social interaction and
infant development.
34
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Table 1: Proximal Care Beliefs Questionnaire. To assess maternal beliefs about infant care,
mothers responded to the following ten statements regarding the care of a 3-month-old infant on
a scale from 1 (completely disagree) to 5 (completely agree). The proximal care beliefs score was
calculated by summing responses to statements in the left column (i.e., proximal care) and
subtracting the sum of responses to statements in the right column (i.e., distal care). This
questionnaire was developed by Keller (2002) and has been used in diverse countries around the
world to assess cultural models of parenting.
It is important to rock a crying baby in the Sleeping through the night should be
arms in order to console him/her trained as early as possible
1----------2---------3----------4------------5 1----------2---------3----------4------------5
(completely disagree) (completely agree) (completely disagree) (completely agree)
Gymnastics/motor stimulation makes a You cannot start early enough to direct the
baby strong infant’s attention towards objects and toys
1----------2---------3----------4------------5 1----------2---------3----------4------------5
(completely disagree) (completely agree) (completely disagree) (completely agree)
When a baby cries, he/she should be nursed It is not necessary to react immediately to a
immediately crying baby
1----------2---------3----------4------------5 1----------2---------3----------4------------5
(completely disagree) (completely agree) (completely disagree) (completely agree)
If a baby is fussy, he/she should be It is good for the baby to sleep alone
immediately picked up
1----------2---------3----------4------------5
1----------2---------3----------4------------5 (completely disagree) (completely agree)
(completely disagree) (completely agree)
A baby should be always in close proximity Babies should be left crying for a moment
with his/her mother, so that she can react in order to see whether they console
immediately to his/her signals themselves
1----------2---------3----------4------------5 1----------2---------3----------4------------5
(completely disagree) (completely agree) (completely disagree) (completely agree)
(completely agree)
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(A)
(B)) (C)
Figure 1: Experimental setup in Study 1 for both babywearers and non-babywearers (A), as well
as the physical condition (B) and visual condition (C) in Study 3.
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Less physical contact More physical contact
Figure 2: Mean difference in overall maternal responsiveness between mothers with less
experience with physical contact and more experience with physical contact in Study 1. Error bars
represent standard error of the mean.
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Figure 3: Mean difference in proximal care belief score associated with infant transport method
in Study 2. Error bars represent standard error of the mean.
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Figure 4: Difference in maternal responses to infants’ vocalizations when not in physical contact
with their infant and when in physical contact (within-subjects) in Study 3. Error bars represent
standard error of the mean.
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