# Offering and showing gestures in 12- to 15-month-old infants in natural contexts: a corpus-based study

Shreejata Gupta, Sofiya Karnovska, Marianne ' Jover, Markus Paulus

► To cite this version:

Shreejata Gupta, Sofiya Karnovska, Marianne ' Jover, Markus Paulus. Offering and showing gestures in 12- to 15-month-old infants in natural contexts: a corpus-based study. European Journal of Developmental Psychology, 2025, A multifaceted Developmental Psychology. The harvest of the 23rd ECDP, 22 (3), pp.395 - 417. 10.1080/17405629.2025.2475993. hal-05469647

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# Offering and showing gestures in 12- to 15-month-old infants in natural contexts: A corpus-based study

Shreejata Gupta<fnref n="1" />,<fnref n="2" />, Sofiya Karnovska<fnref n="3" />, Marianne Jover<fnref n="4" />, Markus Paulus<fnref n="3" />

**Correspondence:**

Shreejata Gupta, CRPN, Aix-Marseille Université, Faculté des Sciences, 3 place Victor Hugo, 13003 Marseille, France

Email: shreejata@gmail.com

## Abstract (150 words)

Developmental theories propose that the ontogeny of sharing behavior builds on earlier emerging social routines of offering objects in caregiver-child-interactions. The current study explored the occurrence of offering and showing behavior in naturalistic contexts, and how caregivers react to these gestures. To this end, we relied on video recordings of spontaneous infant-caregiver interactions from two CHILDES corpora. We analyzed data of six infants from 12 to 15 months comprising 222 tokens of gestures. Across ages, infants showed more offering behavior than showing behavior. Caregivers responded vocally to both types of gestures and showed more object-directed action in the context of the offering gesture. Showing behavior was thus more likely to lead to a unimodal reaction, whereas offering behavior more often led to a bimodal reaction from caregivers. Overall, the study provides evidence for how infant gestures, and the early precursors of sharing behavior, develop in the context of naturalistic caregiver-child-interactions.

**Keywords:** Offering gesture; gesture development; sharing behavior; relational developmental systems; caregiver responsiveness

<footnote n="1">¹Centre de Recherche en Psychologie et Neurosciences (CRPN), CNRS, Aix-Marseille Université, Marseille, France</footnote>

<footnote n="2">²Laboratoire Parole et Langage (LPL), CNRS, Aix-Marseille Université, Aix-en-Provence, France</footnote>

<footnote n="3">³Department Psychology, Ludwig-Maximilians-Universität München, Munich, Germany</footnote>

<footnote n="4">⁴Centre PsyCLE, Aix-Marseille Université, Aix-en-Provence, France</footnote>
**Introduction**

Developmental science has experienced an increasing interest in understanding the early development of prosocial behavior (e.g., Dunfield, 2014; Paulus, 2014; Tomasello, 2008). Behaviors such as helping, sharing, and comforting have been shown to be present in infancy and toddlerhood (e.g., Dahl, 2015; Dunfield & Kuhlmeier, 2013; Paulus et al., 2024). For example, toddlers “help” by returning dropped objects (Warneken & Tomasello, 2006) and share resources when others show interest by reaching for the objects (e.g., Dunfield & Kuhlmeier, 2013), or by vocalizing their interest (Brownell et al., 2009). Recent studies have highlighted early precursors of these behaviors in the first year of life (e.g., Hammond et al., 2017). The early presence of a variety of prosocial behaviors has sparked an intense debate on the developmental origins and emergence of these behaviors (e.g., Paulus, 2014; Tomasello, 2016). How do infants and toddlers come to engage in prosocial behaviors?

Developmental systems theory proposes that early prosocial behavior develops through social interactions, by which infants begin to enjoy interactions with others and progressively develop new strategies to encourage these social exchanges (e.g., Carpendale & Wallbridge, 2023; Dahl & Brownell, 2019; Paulus, 2022). While it recognizes the impact of biological constraints and needs, it focuses on how social abilities and social understanding emerges in the context of social interactions (in which needs are negotiated).

Specifically, what we - as adults and researchers - call prosocial behaviors can also be described as social routines that emerge in the context of regular social exchanges between an infant and its caregiver. For example, give-and-take games, involving the mutual exchange of objects, are a common joyful activity between caregivers and infants. Here, infants acquire routines of how to receive objects from others and how to hand over or offer objects to the other person. Thereby, infants learn about complementary action roles in social exchanges (Mead, 1934). Importantly, infants' object offerings, especially when being prompted by an outstretched hand are often interpreted as sharing behavior in the context of studies on prosocial development (e.g., Dunfield & Kuhlmeier, 2013). Connecting these two research fields, Hay and Murray (1982) demonstrated that engaging 12-month-olds in such games increases subsequent sharing within the same experimental session, in consecutive test trials. This supports the idea that sharing behavior evolves from the social routines of giving and receiving objects (Carpendale et al., 2021; Paulus, 2023). Moreover, it is also evident that this prosocial development is an ontogenetic process, in which the social exchanges reinforce and establish prosocial routines. These routines become more autonomously handled by the infants with increasing age (Dahl & Brownell, 2019; Paulus, 2022).

The current study builds on this theoretical approach. It proposes that offering (or giving, as other scholars label it) behavior emerges from caregiver-infant interactions. Thereby, offering is part of a broader gestural communication context, alongside gestures like pointing (Messinger & Fogel, 1982) and builds on established forms of interpersonal coordination (e.g., Jover & Gratier, 2023). Most interesting is the comparison with showing behavior (that is, the holdout gesture), where infants seek caregiver attention without letting go of the object. In our study, we investigated in greater detail the development of the offering and showing gestures at the beginning of the second year of life (12 to 15 months of age) by means of a longitudinal approach. We explored through analysis of spontaneous infant-caregiver interactions recorded at home. Specifically, we examined how caregivers respond to infants’ offering behavior, based on the idea that infants gradually develop and engage in gestures because they lead to specific reactions of their social environment and, thereby, gain their social and communicative meaning (Carpendale & Carpendale, 2010). In order to better understand the specific responses elicited in the caregivers by the offering behavior, we decided to compare it with caregivers’ reactions to infants’ showing behavior. This
comparison aims to elucidate how infants' understanding of offering behavior compares in relation to their showing behavior within a communicative environment (Paulus, in press).

Typically appearing at 9-10 months (Boundy et al., 2016; Cameron-Faulkner et al., 2015; Choi et al., 2021), giving/offering and showing/holdout gestures are among the earliest forms of gestural communication (Guevara & Rodriguez, 2023), and precursors to index finger pointing (Rodriguez et al., 2015). Evidence suggests a gradual transition from these ostensive gestures to pointing and language acquisition (Choi et al., 2021). Across cultures, contingent caregiver responses to ostensive gestures at 10-12 months and to pointing at 14 months predict expressive language abilities at 18 months (Cameron-Faulkner et al., 2021; Choi et al., 2021). Ostensive gestures often lead to joint engagement and elicit verbal or object-oriented responses, such as object transfer (Cameron-Faulkner et al., 2015). Sharing attention appears to be a key motive, as holdout gestures at 10-11 months elicit more positive responses in joint attention conditions (Boundy et al., 2016). Thus, it has been proposed that the role of caregiver reactions to the ostensive gestures defines the communicative use of the displayed gestures. This study will further investigate how caregivers react to the offering and showing behaviors in infancy.

Despite differences in timing of appearance, affliction in communicative disorders, and caregiver reactions, ostensive gestures are often studied under the broader category of deictic<fnref n="1" /> gestures (for an overview, see Guevara & Rodriguez, 2023). Some studies group giving/offering and showing/holdout gestures together (e.g., Cameron-Faulkner et al., 2015; Choi et al., 2021), while others treat actions like ‘object withdrawal’ as part of offering (e.g., Orr & Rosenbaum, 2023), though it may be a distinct gesture, viz. to show the object. Differentiating between these gestures is crucial, as offering and showing can lead to different social interactions and motives of communication in the pre-speech stage (Boundy et al., 2016). For example, while both gestures serve multiple communicative functions (Moreno-Núñez & Alessandroni, 2021), the offering of objects has previously been ascribed both declarative and imperative functions (i.e. to request for a behavior), and the showing of objects a declarative function (to request the attention of others) (e.g., Beuker et al., 2013). Therefore, while offering involves both sharing attention to an object (declaratively requesting to look at the object) and requests specific behavioral actions (imperatively requesting to take it too) from the caregivers, showing gestures only requires the first step of sharing attention on the same object (Beuker et al., 2013). Understanding these distinctions is key to exploring early intentional communication and prosocial motivations.

This research question is also of particular interest for relational developmental systems (e.g., Racine & Carpendale, 2007; Carpendale et al., 2021) and pragmatic theoretical accounts on communicative development (e.g., Rodriguez, 2009), which stress the importance of infant-caregiver interaction routines for the emergence of communicative actions. From this perspective, infant’s actions, such as object extensions, become ritualized as gestures, having communicative meaning through the caregivers' responses within those interaction contexts (Carpendale et al., 2021). Quantifying markers for the seemingly similar but communicatively distinct gestures of offering and showing in preverbal infants is not only crucial for validating our coding principles; this differentiation helps in understanding the attribution of different communicative intentions behind similar gestures (e.g., by caregivers), which is key to the development of communication and drives subsequent social interactions between infants and adults.

<footnote n="1">¹ Deictic gestures (giving, showing and pointing) are those that are (i) used in communication (at least part of the time), (ii) used to establish reference to external objects or events, and, sometimes, (iii) used to refer to specific individuals or classes of objects or events, and (iv) used at some physical distance from the referent object (Bates et al., 1983).</footnote>
**Current study**

The current study aims to contribute to our understanding of the early longitudinal development of offering and showing behaviors in infancy. It aims at exploring the early precursors of what has been called sharing behavior, building on proposals that gestures gain their meaning because they are embedded in social interactions and receive specific reactions from caregivers (Carpendale & Carpendale, 2010; Paulus et al., 2023). We therefore investigated the extent to which caregivers reacted vocally or with object-directed behaviors to infants’ gestures. We hypothesized that, (i) the offering behavior would elicit more caregiver reactions than the showing behavior, and (ii) *Offer object* gestures will elicit more social interactions expressed as more engagement from the caregivers; while, *Show object* gestures would perhaps elicit reactions enough to validate shared attention on the shown object, thus, richness of reactions is expected to be less in this case. We tested the first hypothesis by directly comparing the proportion of reactions elicited as a function of the frequency of *Offer object* and *Show object* gestures; for the second hypothesis, we conducted exploratory analyses to qualitatively determine the nature of the caregiver reactions and then quantitatively compare the proportions of elicited responses for each gesture type.

Adding to recent experimental and lab-based work, the current study aimed at investigating offering and showing behavior in more naturalistic contexts. It builds on proposals that a full understanding of a phenomenon requires an investigation of how it occurs in naturalistic contexts (Dahl, 2017). For the current study, we made use of corpus data in which French infants were followed longitudinally for several months. We focus on 12- to 15-month-old children as gestural communication increases around the first year of life and thereby provides the opportunity to study the potential age-related changes in offering and showing in greater detail. Following the same infants across several months also allowed for an assessment of developmental trajectories. The current study builds on previous work (in review, Gupta et al., 2024) that identified several gesture types in these children, and expanded it by analyzing the social interactions in which offering and showing gestures appear.

**Methods**

***Data***

For this study, we used video recordings of spontaneous infant-caregiver interactions from two CHILDES corpora: PhonBank French-Paris (Morgenstern & Parisse, 2012) and PhonBank French-Lyon (Demuth & Tremblay, 2008) (available at https://childes.talkbank.org/access/French/). We selected these corpora for two primary reasons: first, the ostensive gestures were already studied longitudinally and their functions identified for these infants in a previous study (Gupta et al., 2024) following already operationalized definitions. Thus, for the current study, this became a template for further annotating the different responses elicited from the adults as a reaction to infants’ ostensive gestures, to further quantify the various factors that might be distinguishing between these two apparently similar looking gestures. This study thus aimed to deepening our knowledge on how the precursors of sharing behavior develop in preverbal infants. Moreover, prior research by colleagues on speech and non-verbal signal development within these corpora offers the potential for detailed cross-study analyses in the future.

The French-Paris corpus includes monthly one-hour recordings, while the French-Lyon corpus consists of bi-weekly one-hour recordings of infants during daily activities. For the sake of uniform sampling from these two corpora, we selected the one-hour videos recorded at 12-, 13-, 14- and 15-months of age for three infants (Antoine, Madeleine,
Theophile) from the French-Paris Corpus; on the other hand, from the French-Lyon corpus, we selected one-hour videos that were recorded at the beginning of 12-, 13-, 14- and 15-months of age for three infants (Anaïs, Marie, Nathan). This was to ensure that we analyze recordings at similar timepoints for the respective infants in the two corpora. Thus, we analyzed 12- to 15-month recordings from a total of six infants, amounting to 25.74 hours of video (58.72 ± SEM 0.27 minutes) per infant. Common contexts included play, social interactions, bathing, feeding, and reading. Gesture production for these infants from 12- to 15-months was previously coded and analyzed in Gupta et al. (2024).

## Coding scheme

We used the ELAN video coding software (Version 6.8 Max Planck Institute for Psycholinguistics, 2024) to code two types of caregiver reactions for our target gestures, that is, showing and offering. Pre-existing codes of offering and showing gestures produced by Antoine, Madeleine, Theophile, Anaïs, Marie and Nathan from a previous study (Gupta et al., 2024) served as the basis for coding the caregivers’ reactions to the infants’ proximal gestures. We coded infant gestures on the basis of the following parameters: we observed the infant’s body postures and/or movements of the hands, legs and head that met the following criteria: (i) the movements are targeted towards specific receivers, (ii) the movements are voluntarily produced by the infant, i.e. they are not based on imitative process (see exclusion criteria) and depend on the attention state of the receiver (iii) the infant waits for the receiver’s response after producing the movement, (iv) in the absence of a response from the receiver, the infant persistently produces the same or different movements until a response is elicited, (v) on elicitation of an ASO from the receiver, the infant stops producing any movement targeted to the receiver (Hobaiter & Byrne, 2014). We coded infants’ actions as potential gestures only if they met all these criteria. These five criteria not only establish that the infants’ gestures can be regarded as being communicative but also that the function of these gestures is derived from their interactive communication with a caregiver. Therefore, we made sure that the communicative motivation behind the gestures was well determined before we ran further analyses (presented in the current manuscript). Those cases where the communicative motivation behind the infants’ gestures were not determined with certainty were not even coded in the original coding scheme. The original coding of these gestures was reliably replicated by a second coder and the agreement between Coder1 and Coder2 was 93% for all gesture forms (including offering and showing gestures).

## Coding Offer object and Show object gestures (Gupta et al., 2024)

*Offer object* and *Show object* are both defined as reaching out one or both hand/s towards the social partner, while holding an object. We differentiated *‘Offer object’* and *‘Show object’* based on the final goal achieved through these gestures. This goal was assessed from the infants' subsequent behaviors after the adult responses were elicited, or after a lack thereof.

The definitions are as follows:

* *Offer object* (henceforth, *Offer*). This behavior was coded when it was clear that the infant wanted to give the object to a social partner, and not just to show it. This was ascertained by a) physical transfer of the object to the social partner at the end of the gesture, b) persistent ‘offer object’ gesturing by the infant in cases where the social partner fails to respond by taking the object, c) eventually dropping of the object in the direction of the social partner in cases where the social partner failed to respond by taking the object, or d) when the child
approached the social partner, while holding the object outstretched in their direction, following initial non-response from the partner (cf. Gupta et al., 2024) **(Supplementary material, S1 & S3)**.

* *Show object* (henceforth, *Show*). This behavior was coded when the child did not let the other person take the object **(Supplementary material, S2 & S4)**.

For instance, an infant extended their hand while holding an object towards an adult and the adult just acknowledged the infant's behavior by uttering a word; the infant kept extending his or her hand toward the adult (thus, persisting with the gesture), or they shook the object while holding it and extending it to the adult (thus, elaborating the gesture). In this case, from the initial reaction of the adult, one might think that it was a showing object gesture, while after considering the infant's subsequent behaviors, one becomes certain that the infant offered the object to the adult and not just to show them. Similarly, in another situation, when the infant extended an object towards an adult and the adult immediately takes it, the infant follows with a head shake gesture, or a scream or pulling the object away from the adult's hand, the gesture rather represents showing the object in this case, and not offering it to the adult. In our coding scheme, this is how we distinguished between offering and showing gestures, even before the nature of the adult responses were taken into account. We thus, did not consider the nature of the adult responses (see below for coding caregivers' reactions) in the definitions of *Offering* and /or *Showing* gestures produced by the infants.

## Coding of caregiver reactions

Gupta et al (2024) focused on the presence or absence of any response from others, including speech, handling of objects, smiles, laughter, gestures, touch, and embraces to identify ‘Offer’ and ‘Show’ without separately classifying these response types. For the present study we focused on two particular response types which were directed towards the infants and actively engaged with the offered objects. We coded caregivers’ vocal reactions and object-actions following offering and showing gestures. For each of the reaction types, we coded if they occurred (‘yes’) or not (‘no’).

* Vocal reactions were defined as the caregiver vocalizing and/or producing a linguistic utterance during or shortly after the production of a gesture. We did not differentiate speech and non-speech vocal reactions. Vocal reactions were coded as having occurred (‘yes’) if the caregiver produced any vocalization (e.g. comment, sound effect) within 3 seconds after the onset of a gesture. Otherwise, they were coded as not having occurred (‘no’). The chosen time interval falls within the response timing range of 2-7s reported on in the literature of infant-caregiver vocal coordination (Jaffe et al., 2001).

* Object-action reaction was defined, following Kosie and Lew-Williams (2024), as the caregiver changing the state, location or spatial orientation (i.e., movement) of an object. Object-action in response to the gesture was coded as having occurred (‘yes’) if the caregiver changed the state, location or spatial orientation of the object used during the gesture within 3 seconds after the onset of a proximal gesture. Changes in the state or spatial orientation of an object could take place while the child was holding onto the object (e.g. the caregiver waving the limb of a stuffed toy), meaning that the child did not have to let go of the object for an object action to occur. If no changes in the state, location or spatial orientation of the object occurred (i.e., no movement of the object), this behavior was coded as ‘no’. Based on this definition, a caregiver merely receiving and passively holding an object without moving it would not count as an object action. This was to ensure that a passive acceptance of the object
followed by the opportunity provided by the offering of the infant was not overestimated as a distinguishing factor in responses elicited in the adults. Rather, an active participation of adults with the object will be an indicator of active social participation, and we wanted to test whether there are any differences between the *Offer* and the *Show* gestures in eliciting active social exchanges between the infant and the adult.

Interestingly, in our dataset, none of the infants in the age group of 12- to 15-months did not produce any words, more specifically, during the production of these *Offer* and *Show* gestures that we studied here. Thus, infants’ offering an object or showing an object was not expressed through language. We determined the type of gesture based on the infants’ behaviors, following a response elicited from the adults, or even a lack thereof. Thus, this study explores how early precursors of sharing behavior in infants become socially reciprocated and perhaps get embedded in social interactions through caregiver responses.

## Analyses

All analyses were carried out in R version 4.2.0 (R Core Team, 2024) using the dplyr (Wickham et al., 2023), lme4 (Bates et al., 2015), car (Fox & Weisberg, 2019), and ggplot (Wickham, 2016) packages. First, we calculated the total number of *Offer* and *Show* gestures produced by the six infants across 12- to 15-months of age and then calculated the frequency of occurrence (total number observed/minutes of video recording for each infant). We also calculated the relative percentage of *Vocal* reactions and *Object-action* reactions from adults, as a function of the number of gestures produced. It is noteworthy that not all six infants produced the *Offer* and *Show* gestures at every age point. This is reflected in the ‘n’ values presented in **Table 1** (*Offer object*: at 12-, 13-, 14-months, n = 5, at 15-months, n = 6; *Show object*: at 12- and 13-months, n = 5, at 14- and 15-months, n = 3). To correct this and to account for potential age effects on gesture and adult reactions, we ran three generalized linear mixed models (GLMM) at the observation level, to test the fixed and random effects of age and individuals on the gesture types produced by the infants, as well as the types of reactions elicited in the adults, respectively. We then present descriptive statistics, comparing the average numbers of each gesture type produced and the average relative percentages of each reaction type elicited as a function of the gesture types. Finally, we compared which gestures elicited a combination of the two responses (bimodal reaction) in contrast to those that elicited only one type of reaction (unimodal reaction) using a GLMM.

## Results

### Descriptive data

In our dataset of six infants aged 12-15 months, we observed a total of 222 tokens of ostensive gestures (of which, *Offer* = 172). We excluded 21 observations from our final analyses due to the lack of both *Vocal* and/or *Object-action* reactions (in 16 instances = 7.2% of observed ostensive gestures), or when the adults were absent in the videos. In these particular cases, the adult reactions, one of our main target measurements for the study to compare between *Offer* and *Show* gestures, were absent or could not be reliably coded due to their unavailability in the recordings. Notably, 68.75% of the no-reaction instances followed *Show* gestures, with 50% occurring during play. Our final analyses were conducted at the level of observations, including 201 tokens of ostensive gestures (of which *Offer* = 164). The age-group-wise distribution of the observed tokens are as follows: 12-months: 36 observations; 13-months: 64 observations; 14-months: 56 observations; 15-months: 44 observations. 91.54% of all ostensive gestures received *Vocal* reactions and 76.62% received *Object-action* reactions. Average (± SEM) proportion of contexts represented in the video
recordings analyzed for this study included 29.25% (± 5.78) of bath-time, 22.50% (± 2.99) of feeding time, 17.14% (± 8.65) of play time, 7.85 (± 1.07) of social interactions and 7.88 (± 0.93) of reading as well as other activities. Ostensive gestures were produced: 58.2% during play, 17.91% during other social interactions, 13.43% during reading, 9.45% during feeding, and 1.49% during bathing.

## Age-effect and individual variations

We conducted three generalized linear mixed models (GLMM) to examine the fixed effect of age on the frequency of production of *Offer* and *Show* gestures and the frequency of *Vocal* and *Object-action* reactions elicited on the level of observations. We assessed fixed effects of age on *Vocal* and *Object-action* reactions using two binomial GLMMs. Gesture type was treated as nested within individuals for these analyses. We also analyzed potential age effects on gesture type using a binomial GLMM with age as a fixed factor and individual ID as a random factor.

For the caregiver reaction types, no significant effects of age were found at the observation level. There was a significant age effect on gesture type at the observation level, that is, at 15 months, *Show* gestures were significantly less likely to occur than *Offer* gestures ($\chi^2[3] = 7.89, p < 0.05$). The log-odds of *Show* gestures occurring at 15 months were -1.89 (SEM = 0.68), corresponding to an odds ratio of 0.15 of *Show* gestures at 15 months (Appendix A).

## Effect of gesture types

The average frequency of *Offer* gestures (0.13, SEM = 0.03) observed in 12- to 15-months old infants is significantly higher than the average frequency of *Show* gestures (0.04, SEM = 0.01) ($t(35) = 2.53, p = 0.01$).

The age-wise distribution of the frequency of *Offer* and *Show* in our dataset is presented in Table 1, Figure 1(a).

## Gesture types and subsequent reactions elicited

The average relative percentage of *Vocal* reactions, across age and individuals is comparable between *Offer* (Mean = 91.6%, SEM = 2.91) and *Show* (Mean = 95.3%, SEM = 3.40) gestures (Figure 1b).

However, the average relative percentage of *Object-action* reactions to *Offer* gestures (86.4%, SEM = 3.83) is significantly higher than those to *Show* gestures (15.2%, SEM = 5.50) ($t(37) = 10.96, p < 0.0001$) (Figure 1b).

We assessed if gesture type was related to the frequency of *Vocal* and *Object action* reactions at the observation level in two subsequent binomial GLMMs with gesture type as a fixed effect, and age nested within participants. In the model concerning vocal reactions, we found that gesture type did not have a significant effect on relative frequency of *Vocal* reactions elicited, indicating that *Vocal* reactions occurred at similar rates for both gesture types. In the model concerning object action reactions, we found that gesture type had a significant effect on relative frequency of *Object-action* reactions elicited ($\chi^2[1] = 38.09, p < 0.001$), with the log-odds for *Object-action* reactions occurring being -3.28 (SEM = 0.53) for *Show* in comparison to *Offer*. That is, the odds ratio of *Object-action* reactions for *Show* gestures was 0.04 that of *Offer* gestures, making *Object-action* reactions less frequent in *Show* gestures than in *Offer* gestures. Therefore, this confirmed our first hypothesis that the offering behavior would elicit more caregiver reactions than the showing behavior.

The age-wise distribution of the average relative percentage of *Vocal* and *Object-action* reactions elicited respectively to *Offer* and *Show* gestures is provided in Table 1.
<figure><img src="image_2.png" /><figcaption>**Figure1:** (a) Average frequency of Offer object and Show object gestures in 12- to 15-month-old infants (n = 6); (b) average percentage of Vocal reactions and Object-action reactions elicited to Offer object and Show object gestures, respectively. Bold lines with SE of mean bars indicate the population level averages across individuals. Shapes refer to average values for individuals as shown in the legend.</figcaption></figure>
<table><caption>**Table 1.** Average frequency (± SEM: Standard Error of Mean) of Offer object and Show object gestures in 12- to 15-months old infants (n = 6), and the average percentage of Vocal reactions and Object-action reactions elicited to Offer object and Show object gestures, respectively</caption><thead><tr><th rowspan="2">age (months)</th><th colspan="2">n</th><th colspan="2">Average frequency of Offer object and Show object gestures (± SEM)</th><th colspan="2">Average percentage of Received Vocal Reaction (± SEM)</th><th colspan="2">Average percentage of Received Object-action Reaction (± SEM)</th></tr><tr><th>Offer</th><th>Show</th><th>Offer</th><th>Show</th><th>Offer</th><th>Show</th><th>Offer</th><th>Show</th></tr></thead><tbody><tr><td>12</td><td>5</td><td>5</td><td>0.08 (0.05)</td><td>0.04 (0.01)</td><td>98.8 (1.25)</td><td>100 (0)</td><td>90 (10)</td><td>12 (12)</td></tr><tr><td>13</td><td>5</td><td>5</td><td>0.18 (0.09)</td><td>0.04 (0.01)</td><td>81.7 (8.73)</td><td>85 (10.0)</td><td>85.1 (9.2)</td><td>15 (10)</td></tr><tr><td>14</td><td>5</td><td>3</td><td>0.16 (0.06)</td><td>0.05 (0.01)</td><td>90.5 (5.86)</td><td>100 (0)</td><td>90.1 (4.28)</td><td>19.4 (10.0)</td></tr><tr><td>15</td><td>6</td><td>3</td><td>0.11 (0.04)</td><td>0.04 (0.12)</td><td>95 (4.08)</td><td>100 (0)</td><td>81.6 (7.80)</td><td>16.7 (16.7)</td></tr></tbody></table>

**Unimodal versus bimodal responses to each gesture type**

Among the 201 instances of observations of *Offer* and *Show* gestures, 67.16% elicited bimodal reactions, i.e. both *Vocal* and *Object-action* reactions. Bimodal responses to ostensive gestures were, thus, significantly higher than unimodal ones, i.e. either *Vocal* or *Object-action* reactions ($\chi^2(1, N = 201) = 23.69, p < 0.0001$).

When considering *Offer* gestures alone, 78% of 164 instances elicited a bimodal response, i.e. both *Vocal* and *Object-action* reactions, while only 19% of the 37 instances of *Show* gestures alone elicited a bimodal response. Thus, bimodal responses elicited to *Offer* gestures were significantly more ($\chi^2(1, N = 135) = 108.45, p < 0.0001$) than those elicited by *Show* gestures.

We assessed the effect of gesture type on the elicitation of bimodal (1) or unimodal (0) response using a binomial GLMM with gesture type as a fixed effect, and age nested within participants. Gesture type had a significant effect on gesture bimodality ($\chi^2[1] = 28.55, p < 0.001$). The log-odds of bimodal responses in instances of *Show* gestures were -3.09 (SEM = 0.57). These results correspond to an odds ratio of 0.05 for bimodal responses in *Show* gestures. The odds ratio indicates that *Show* elicited 0.05 times the number of bimodal responses, in comparison to *Offer* gestures. In other words, bimodal responses occurred less often in instances of *Show* gestures.
Thus, in our exploratory analyses, we identified two different types of caregiver-
reactions, viz., *Vocal* and *Object action* reactions. Further, on comparison between the
proportions of these two reaction types elicited as a function of the frequencies of the gestures
produced by the infant support our second hypothesis that *Offer object* elicited more social
interactions, while *Show object* elicited reactions enough to share attention on the shown
object. This is reflected in our findings that *Show object* only mostly elicited a unimodal
*Vocal* reaction in similar proportions as did *Offer object*; however, *Offer object* elicited
significantly more *Object action* reactions in addition to *Vocal* reactions (bimodal) thus,
facilitating more social interactions with the infants.

Discussion

Transferring objects to each other plays an important role in human social behavior. Most notably, sharing resources with each other is a hallmark of prosocial behavior (Dunfield, 2014; Paulus, 2014) and helps individuals to establish and maintain social bonds (Mauss, 1954). The current study follows proposals that sharing behavior and object transfer is rooted in social routines of offering objects in caregiver-infant-interactions (Carpendale et al., 2021; Paulus, 2022). It explored the occurrence and developmental trajectory of offering and showing gestures in naturalistic contexts by analyzing video recordings of spontaneous child-caregiver interactions of 12- to 15-month-old infants from two CHILDES corpora. Moreover, we explored the modality of caregiver reactions to infant behaviors. Overall, infants showed more offering behavior than showing behavior. Caregivers' reactions differed between the two gestures. Whereas both gestures received vocal responses, the offering gesture received more object-directed and also more bimodal caregiver responses. The current study provides new evidence on the frequent occurrence of offering gestures in infancy and demonstrates how they lead to rich caregiver reactions. We will discuss the findings in greater detail in the subsequent paragraphs.

Differences Between Offer and Show Gestures

We found significant differences between *Offer* and *Show* gestures in both frequency of their occurrences and the types of social responses they elicited. This supported our first hypothesis that the offering behavior would elicit more caregiver reactions than the showing behavior. *Offer* gestures elicited more object-directed and bimodal (*Vocal* and *Object-action* reactions) responses. *Show* gestures mostly received unimodal vocal responses. This in turn supported our second hypothesis and our exploratory analyses established that *Offer object* resulted in more social interactions expressed through bimodal reactions from the caregivers, while, *Show object* elicited less riche unimodal *Vocal* reactions to share attention on the shown object. This could be interpreted as reflecting distinct communicative acts shaped by typical caregiver responses (Carpendale & Wallbridge, 2023).

Specifically, where infants present objects for transfer, the gesture shares the
morphological characteristics and behavioral forms of what has also been called sharing
behavior in other lines of work (e.g., Dunfield et al., 2011). This aligns with proposals that
object-oriented gestures act as early forms of sharing in social exchanges like give-and-take
games (Hay & Murray, 1982; Paulus, 2022). Why do infants engage in these behaviors? Our
finding that caregivers show rich multimodal feedback is in line with the view that infants
engage in this behavior as a kind of invitation for interaction. Indeed, sharing items with
others is a prototypical way of starting an interaction with another person. For example,
sharing toys allows for the pleasure of joint play. In contrast, the showing gesture led to
unimodal vocal responses. We interpret it as an indicator that infants primarily sought to share attention.

Previous studies on ostensive gestures in infants report fewer instances of offering and showing gestures compared to our findings (van der Klis et al., 2023; Orr & Rosenbaum, 2023; Boundy et al., 2016). This discrepancy could stem from those studies being conducted in controlled, task-based settings and organized play sessions (van der Klis et al., 2023; Orr & Rosenbaum, 2023) or focusing solely on play contexts (Donnellan et al., 2020; Boundy et al., 2016). In contrast, our use of pre-recorded videos from naturalistic settings—including play, feeding, reading, and bathing—captured a more diverse range of social contexts that allow for pre-speech communicative gestures. Our findings, thus, add to experimental work and demonstrate the importance of studying infant behavior in naturalistic contexts (Dahl, 2017).

Caregiver Responsiveness and Social Interaction

We examined caregiver responses, building on proposals that social interactions are the basis from which early gesture use emerged (Carpendale & Carpendale, 2010; Paulus et al., 2023). Specifically, we investigated whether caregivers react differently to offer and show gestures since, from a relational developmental systems perspective, caregiver responses shape the social meaning of those gestures (Carpendale et al., 2021). Previous research (e.g., van der Klis et al., 2023) indicates synchrony in caregiver responses during predictable interactions, with multimodal responses more common considering offering and showing gestures as a single category (van der Klis et al., 2024). Donnellan et al. (2020) also reported more direct responses to giving gestures. Our study extends this by showing that caregivers provide more frequent bimodal reactions (*Vocal* and *Object-action*) to *Offer* gestures than to *Show* gestures. Boundy et al. (2016) noted that caregiver feedback often clarifies the ambiguity in early gestures, aligning with our observation that show gestures frequently result in no-reaction instances, while offer gestures elicit structured social interactions. That is, while both gestures overlap in several aspects of their morphology (e.g., the shape of the extended hand), they develop different meanings based on the fact that they are treated differently by infants' social environment.

The higher incidence of bimodal responses to offer gestures indicates a social reinforcement mechanism, which may ritualize these gestures through contingent caregiver feedback (Mead, 1934; Cameron-Faulkner et al., 2015; Liszkowski et al., 2006; Dimitrova et al., 2015). Our findings fit well to relational developmental systems theory, which posits that early gestures gain meaning through interaction routines (Carpendale et al., 2021). Yoder and Munson (1995) highlight the importance of caregiver responsiveness for developing intentional communication and language.

Notably, vocal reactions were consistently present across both gesture types. Our results indicate that if a caregiver does decide to respond to an ostensive gesture at all, vocal reactions may be the preferred channel. Previous research has linked maternal responsiveness to infants' early pre-communicative behaviours to their later language development (Yoder & Munson, 1995; Yoder & Warren, 1999). The fact that all gestures contingently led to vocal responses by caregivers, that in turn will help the infant to acquire language (e.g., Tamis-LeMonda et al., 2014), highlights the developmental path of early language acquisition. It follows that the relationship between ostensive gestures and language development reported in the literature (Cameron-Faulkner et al., 2021; Choi et al., 2021) may be the result of consistent presence of vocal reactions to infants' object extensions.
## Age-related effects and individual variability

Our quantitative analysis did not reveal a significant effect of age or individual variation in the use of *Offer* and *Show* gestures among infants, indicating that these gestures may stabilize early in the second year of life (Guevara & Rodriguez, 2023). However, one should be aware that our sample was very small and that we were likely not able to detect age-differences. Indeed, prior studies have shown age-related changes in gesture frequency; for instance, Carpenter et al. (1998) noted more frequent giving gestures around 12 months, and Liszkowski (2006) observed an increase in showing gestures after 12 months.

Moreover, while not the focus of our study, a qualitative view on the data suggests some individual variability, with infants like Anaïs, Antoine, and Marie showing a greater use of the *Offer* gestures. This aligns with research demonstrating individual differences in gesture use. It has been proposed that this could be explained by temperament and infants’ social environment (Cochet & Vauclair, 2010). From a theoretical point of view, a systems perspective would propose that individual differences in infants’ gesture use might be explained by how the social environment interacts with the infant. Indeed, previous research identified relations between parental pointing and infant pointing gestures (e.g., Rowe & Goldin-Meadow, 2009). However, from our dataset, we could not acquire a comprehensive overview of how interactions between the different infant-caregiver dyads developed over time. Thus, we refrain from speculating on the underlying causes leading to the observed individual differences in the data. Nevertheless, it is to be clarified here that the higher frequencies of offering gesture in case of certain individuals were not a result of overestimation of the gestures during annotation. Our coding scheme takes into account the consequence behaviors from the infants after the response is elicited by the adults, or even in case of an initial absence of response from the social partners. Therefore, the chances of misconstruing a ‘showing’ object action as an ‘offering’ object action is avoided in our coding scheme. Anecdotally speaking, we can talk about only a few instances when the adults misunderstood the infant’s act of showing for offering and tried to take the object; as a consequent reaction, the infant immediately expressed their discontent about this response from the adult and thus we annotated these gestures as ‘showing’, taking into account the behavior of the child.

## Limitations and future directions

The current study adds to the literature on the development of offering and showing gestures by analyzing their occurrence in naturalistic contexts based on previous work with corpus data (Gupta et al., 2024). While this approach has its unique strengths (Dahl, 2017) and allows for a longitudinal view, it also comes with some limitations. The limitations include a small sample size and variability in the social contexts in which the recordings were made. While the study’s strength was to investigate more than 200 tokens of gestures, it was limited in terms of number of participants. The absence of age effects in our study may be due to the limited age range of a few months and the small sample. It would be important to expand on the current study and investigate a greater sample with a more extended age range.

Moreover, we attempted to identify differences between the offering and showing gestures. This attempt was warranted by the idea that the two gestures come to serve different communicative functions in human communication. Although we used very precise descriptions to distinguish between the *Offer* and *Show* gestures, and while these two gestures (based on our initial definition) elicited (on the group level) different responses from the adults, one could wonder whether it is justified to differentiate between these two similar looking gestures. To which extent is there a difference in the morphology and to which extent
is there a difference based on the differential response by caregivers? One proposal for future research would be to further investigate the differences between *Offer* and *Show* gestures by comparing the associated micro-behaviors (Boundy et al., 2016) including the kinematics of these gestures (e.g., handshape, hand movement pattern, laterality; see Cochet et al., 2014, 2015) and other co-occurring behaviors (e.g., eye gaze, vocalizations, smiles) - both from the infant and the caregiver side.

**Conclusion**

This study investigated the occurrence of offering and showing gestures in 12- to 15-month-
old infants in naturalistic contexts. Children engaged in more offering gestures than showing
gestures. Caregivers were more likely to show bimodal responses to children’s offering than
to their showing suggesting that caregivers interpret the communicative function of these
gestures differently. Our findings are in line with proposals that underscore the role of social
context in shaping early communicative behaviors.

**Data availability:** The data that support the findings of this study are available from the corresponding author, [author initials], upon reasonable request.
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