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http://jbd.sagepub.com/International Journal of Behavioral Development

http://jbd.sagepub.com/content/32/2/89The online version of this article can be found at:

DOI: 10.1177/0165025407084055

2008 32: 89International Journal of Behavioral DevelopmentKeiko K. Fujisawa, Nobuyuki Kutsukake and Toshikazu Hasegawa

Reciprocity of prosocial behavior in Japanese preschool children

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International Journal of Behavioral Development2008, 32 (2), 8997

http://www.sagepublications.com

2008 The International Society for theStudy of Behavioural Development

DOI: 10.1177/0165025407084055

Analyses of social interactions between peers provide import-

ant insights into childrens social development, as peer inter-

actions are associated with enhanced sociocognitive abilities,

emotional understanding, and social skills (Dunn, 2004;

Dunn & Slomkowski, 1992; Rubin, Bukowski, & Parker,

1998). Analyses of social interactions also provide direct

information about social relationships between peers because

the accumulation of previous social interactions between two

children determines the characteristics of their dyadic

relationship (and conversely, the characteristics of social

relationships are reflected in future interactions between

them; Hinde, 1979).

The exchange of similar prosocial actions between indi-

viduals (hereafter defined as reciprocity; note that this defi-

nition does not include exchanges of negative behavior such as

aggression) has been regarded as having an important role in

childrens social development (Hinde, 1979; Ross, Cheyne, &

Lollis, 1988; Youniss, 1986). Therefore, studies of reciprocity

may provide insight into social development in children for the

following reasons. First, peer interaction involving reciprocity

provides an optimal context for fostering the development of

prosocial behavior (reviewed in Eisenberg & Fabes, 1998).

This is because preschoolers have other-oriented or relational

concerns when responding prosocially toward their peers,

whereas they have authority- or punishment-related motives

when responding to adults requests (Eisenberg, Lundy, Shell,& Roth, 1985). In addition, children are reinforced for being

prosocial by exchanges of positive responses among peers.

Preschool children respond to peers prosocial actions

frequently in a reinforcing manner (e.g., smiles, approving of

the act, showing thanks, and sustaining interaction) compared

with the responses by their teachers in classrooms (Eisenberg,

Cameron, Tryon, & Dodez, 1981). Furthermore, as observed

by Eisenberg et al. (1981), children who reacted positively to

others spontaneous prosocial behaviors frequently received

positive feedback for their own prosocial behaviors.

Second, reciprocity plays an important role in the cultiva-

tion and regulation of social relationships. For example, Ross

and Lollis (1989) reported that reciprocity of positive inter-

actions gradually emerges among toddlers, which suggests the

gradual development of social relationships. Reciprocal inter-

action was also observed in dyads of stable friends (Howes,

1983). Reciprocity is regarded as an important component of

friendship (Rubin et al., 1998) because balanced social contri-

butions are emphasized at all ages when children describe

friendship (Bigelow & LaGaipa, 1975; Goodnow & Burns,

1985; Hartup, 1995; Laursen & Bukowski, 1997; Laursen &

Hartup, 2002).

Finally, studying reciprocity in children contributes to our

understanding of childrens cognitive development because

reciprocity is based on complex sociocognitive abilities such as

detecting anothers cheating behavior, recalling past inter-

actions, and perceiving others needs (Trivers, 1971). The

important role of reciprocity in forming and maintaining social

relations, which maximizes the coordination in social inter-

action, seems to favor cognitive development (Hartup, 1995).As described earlier, compared with other types of social

interaction, reciprocity offers unique perspectives for under-

standing social development because reciprocity inevitably

involves two interactants. As a result, researchers need to

Reciprocity of prosocial behavior in Japanese preschool children

Keiko K. Fujisawa Nobuyuki Kutsukake and Toshikazu HasegawaKeio University, Japan and University of Tokyo, Japan University of Tokyo, Japan

This study investigated the reciprocity of prosocial behavior among 3- and 4-year-old Japanese

preschool children during free-play time. Matrix correlation tests revealed positive correlations

between the frequencies of object offering given and received within dyads and between the frequen-

cies of helping given and received within dyads. These results suggest that young children recipro-

cate prosocial behavior spontaneously. Positive correlations were also found between the frequencies

of object offering and helping behavior exchanged within dyads, suggesting that children exchanged

the two types of prosocial behaviors (i.e., interchanged).The interchange was independent of both

reciprocity within object offering and reciprocity within helping behavior in 4-year-olds. Friends

reciprocated object offerings more frequently than non-friends, suggesting that friendship affects the

quantitative aspect of reciprocity. These data provide refined evidence of reciprocity among children

and also suggest that reciprocity becomes more complicated as children grow older.

Keywords: friendship; naturalistic observation; preschool children; prosocial behavior; reciprocity

The authors would like to thank R. Kohata, Y. Usui, and the teachers

who participated in this study for their extensive cooperation.We also

thank all the children and their parents for their participation. C.

Hemelrijk kindly provided the Matrixtester program, for which we are

grateful. K. Ozaki kindly provided us with statistical comments. This

study was supported by Japan Society for the Promotion of Science

(JSPS) Research Fellowships for Young Scientists which were awarded

to the first and the second authors and by the JSPS 21st century COE

program: Center for Evolutionary Cognitive Sciences at the University

of Tokyo.

Correspondence should be sent to Keiko K. Fujisawa, Dept of

Humanities and Social Science, Faculty of Letters, Keio University,

Mita 21545, Minato-ku, Tokyo 1088345, Japan; e-mail:

[email protected]


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consider the prosocial acts of two children simultaneously,

which is not always required in studies of social behavior

(Hinde & Stevenson-Hinde, 1987).

Many experimental studies (Birch & Billman, 1986;

Dreman & Greenbaum, 1973; Levitt, Weber, Clark, &

McDonnell, 1985; Staub & Sherk, 1970) have revealed the

existence of temporal reciprocity (i.e., an immediate

exchange of similar acts). Reciprocity of prosocial behavior has

been confirmed in children of at least 2 years of age (Levitt et

al., 1985). In addition, it has been reported that even 6-month-

old infants show a prototype of reciprocity (responses to peers

distress, Hay, Nash, & Pedersen, 1981; and responses to peers

touch, Hay, Nash, & Pedersen, 1983), even though these

results did not necessarily suggest that these very young

children were capable of having specific social relations with

peers (Hay et al., 1983).

Ross et al. (1988) proposed that reciprocation in the long-

term reflects the quality of relationships between young

children. Although temporal reciprocity is typically examined

in experimental studies, reciprocity examined in naturalistic

observational studies (Howes, 1983, 1987; Strayer, 1980) can

represent dyadic reciprocity, that is, balanced exchanges of

similar acts between individuals in the long-term. If the dyadmembers have a good relationship, a child does not require an

immediate return of his or her favor because of the expectation

that the partner will respond in the future when needed.

Temporal reciprocity may, therefore, be unrealistic in natural

situations because it is likely that a child who is kind to a peer

does not necessarily need reciprocation at that moment. Based

on this argument, the reciprocity referred to in this article is

dyadic reciprocity, not temporal reciprocity.

Although reciprocity among children was studied intensively

a few decades ago, more recent studies are rare. Also, previous

studies on reciprocity have encountered both theoretical and

statistical problems. For example, Strayer (1980) used natura-

listic observation to investigate reciprocity in groups of

preschool children and reported significant positive associ-

ations between giving and receiving prosocial behaviors within

dyads. However, it is likely that children had particular class-

mates with whom they spent long (or short) periods and with

whom they affiliated frequently (or less frequently). For

example, friends among preschoolers are typically character-

ized as individuals who frequently share positive activities

(Howes, 1983). Because Strayer (1980) did not control for

variations in affiliation frequency with different classmates,

reciprocity might have been statistically detected even if

children did not reciprocate selectively to classmates from

whom they had received prosocial behavior, but simply

directed prosocial behavior toward one with whom they were

frequently affiliated. In other words, it is possible that the reci-procity of prosocial behavior was confounded by the frequency

of affiliative interaction among peers. In addition, previous

studies focused on only one form of prosocial behavior (Birch

& Billman, 1986; Levitt et al., 1985) and did not examine the

possibility that children repaid one form of prosocial behavior

with another form of prosocial behavior (hereafter, inter-

change).This possibility is highly likely because preschool-age

children exhibit various kinds of prosocial behaviors and can

choose behavior appropriate for their partner (Eisenberg &

Fabes, 1998). Finally, a previous approach that used a simple

correlation test to investigate reciprocity (Strayer, 1980) is

problematic from a statistical standpoint because data points

from the same children were not independent.That is, such an

approach violates the statistical assumption that each data

point is independent. The problem is exaggerated when there

are significant individual differences in behavioral capabilities

or tendencies.

In this study, we analyzed reciprocity among 3- and 4-year-

old Japanese children during free-play time. In the first part of

this study, we used an innovative statistical method (the matrix

correlation test or Kr test; Hemelrijk, 1990a, 1990b; see

Methods for details) that overcame the problems in the

previous studies mentioned above. This test has advantages

over simple and ordinary correlation tests. First, this test

includes a random permutation procedure, which resolves the

problem of data dependency within a social interaction matrix

(Hemelrijk, 1990a; Manly, 1997; Sokal & Rohlf, 1995).

Second, the individual differences in behavior and the vari-

ations between behaviors are taken into account in this test,

making the test results robust to the effect of outliers (e.g.,

children who are extremely prosocial or a behavior with low

occurrence compared with other behaviors). We specifically

examined: (a) whether peers reciprocated prosocial behavior,

(b) whether the reciprocity of prosocial behavior was inde-

pendent of the frequency of affiliation in a dyad, and (c)

whether one type of prosocial behavior was interchanged for adifferent type of prosocial behavior. Based on these analyses,

we aimed to provide sophisticated evidence of reciprocity

among preschoolers.

In the second part of this study, we investigated the associ-

ation between reciprocity and friendship. Although reciproc-

ity is assumed to be a common characteristic of friendships

(Bukowski & Sippola, 1996; Rubin et al., 1998), few studies

have empirically examined differences in reciprocity between

friends and non-friends in young children (see Youniss, 1986

for a study of elementary school children), and most experi-

mental studies of prosocial reciprocity have not considered

the effect of friendship itself (Dreman & Greenbaum, 1973;

Leiter, 1977; Levitt et al., 1985). Previous studies have

tended to classify dyadic relationships dichotomously accord-

ing to whether the prosocial behavior was reciprocated

(Dreman & Greenbaum, 1973; Leiter, 1977; Levitt et al.,

1985). This dichotomy, however, may underestimate occur-

rences of reciprocity among non-friends, since it is unlikely

that children are entirely non-reciprocal to their non-friends

prosocial behavior under natural conditions. For example,

observational reports have noted that reciprocity occurred even

in dyads that did not necessarily meet friendship criteria

(Howes, 1983).Thus, the non-friends may reciprocate to some

extent, but the degree of the reciprocation may be less than the

degree of reciprocation between friends.To test this possibility,

a measure that enables us to examine the quantity of reci-

procity is necessary. To use a quantitative proxy measure ofdyadic reciprocity, we improved Silk, Seyfarth, and Cheneys

(1999) Reciprocity Index so that we could examine the balance

in exchanges of social behaviors within dyads, accounting for

the frequency of the social behavior that occurred within the

dyads (see Methods). Using this measure, we investigated

whether friends reciprocated more in quantity than non-

friends.

This study has two broad implications for understanding

social development in preschoolers. First, previous studies

rarely investigated the developmental process of reciprocity in

young children (Strayer, 1980; Strayer, Wareing, & Rushton,

1979; see Youniss, 1986 for developmental changes in

elementary school children). We predicted that reciprocity or

90 FUJISAWA ET AL. / JAPANESE PRESCHOOLERS


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interchange would be more apparent among 4-year-olds than

among 3-year-olds for the following two reasons. First,

sociocognitive abilities increase as young children become

older (Astington, 1993), and these abilities constitute the basis

for reciprocal exchanges. Second, prosocial behavior changes

both qualitatively and quantitatively as children become older

(Eisenberg & Fabes, 1998), with older children engaging in a

greater variety of prosocial behaviors than younger children.

This change enables older children to choose a given type of

prosocial behavior that is appropriate to the social context

when reciprocating or interchanging. We also predicted that

the effects of friendship on the degree of reciprocity would

increase in 4-year-olds relative to 3-year-olds. This is because

reciprocity is assumed to be a common characteristic of friend-

ships (Bukowski & Sippola, 1996; Rubin et al., 1998), and

friendships among 4-year-olds are more stable than those

among 3-year-olds (Guralnick & Groom, 1988; Hymel, 1983;

Uehara, 2004). The second implication relates to cultural

differences. Participants of most previous studies on reciproc-

ity of prosocial behavior have been from western cultures

(Birch & Billman, 1986; Levitt et al., 1985; Staub & Sherk,

1970; Strayer, 1980; Strayer et al., 1979); understanding of

prosocial behavior in eastern cultures is thus limited. Incontrast to western societies in which children are expected to

learn prosocial behavior incidentally, Japanese society encour-

ages children to demonstrate prosocial behavior beginning in

their early years (Stevenson, 1991). For example, although

North American mothers often make their children share with

peers when intervening in object conflicts (Ross, Tesla,

Kenyon, & Lollis, 1990), teachers in America often do not

respond in a reinforcing manner to childrens prosocial behav-

iors (Eisenberg et al., 1981). In contrast, Japanese teachers

create various types of settings that reinforce childrens proso-

cial behavior (Stevenson, 1991). This study was not designed

to test the cultural differences between western and eastern

cultures directly; however, it may help to fill gaps in our knowl-

edge of social development in preschoolers.

Method

Participants

The study was conducted at a public nursery school in Tokyo.

Two classes of 3-year-olds (Class 3A: nine boys and five girls;

mean age = 44.1 months, SD = 3.0; Class 3B: eight boys and

eight girls; mean age = 43.4 months, SD = 3.4) and two classes

of 4-year-olds (Class 4A: nine boys and three girls; mean age =

55.1 months, SD = 2.5; Class 4B: seven boys and nine girls;

mean age = 54.8 months, SD = 3.3) participated in this study.

Class 3A and Class 4A consisted of entirely different children,

whereas Class 3B and Class 4B consisted of mostly the same

children. This means that this study included both cross-

sectional (3A and 4A; 3A and 4B; 3B and 4A) and longitudi-

nal (3B and 4B) designs in terms of age-difference

comparisons. This was because classes marked with a B had

participated in our 2-year longitudinal project. One boy had

left Class 3B, and one girl had joined Class 4B when observa-

tion of the 4B group began. All of the children were Japanese

and spoke Japanese as their first language.

Procedure

Observational data were collected during morning free-play

time for a school year (except for summer and winter holidays).

All observations were conducted in a classroom. During the

study period, one or two teachers were present during class-

room observation. Twenty sessions of 5-minute focal observa-

tions of each child (i.e., 100 minutes per child in total) were

videotaped. Focal observations for each child in each class were

conducted in a random order in each session. It took about2 weeks to observe all children in a class for a session. If a child

to be filmed was absent on the scheduled observation day, he

or she was filmed as soon as possible afterward for an even

accumulation of observational data. Observations were not

made when a focal child was engaging in teacher-structured

activities. Children and teachers were accustomed to having

their activities filmed before this study commenced. One

observer, who had established a good rapport with the children

and teachers before starting this study, moved around freely in

the classroom and filmed all the children with a portable video

camera.

CodingFrequencies of affiliative and prosocial behaviors that occurred

between a focal child and peers were coded. The initiator and

the recipient of the social behavior were also identified.

Affiliative behavior. Six kinds of affiliative behaviors were

coded: hand to body, body to body, talking, show, approach,

and look (see Table 1 for descriptions). These behaviors were

mostly based on Strayers (1980) coding but talking and

show were added.

Prosocial behavior. Two kinds of prosocial behavior were

coded: object offering and helping (see Table 1 for descrip-

tions). These behaviors were chosen for this study because oftheir relatively frequent occurrence during the preschool

period (Eisenberg & Fabes, 1998).

We did not code prosocial behaviors that appeared to benefit

the initiator as well as the recipient, such as behaviors that

occurred as part of a play ritual or as cooperation. Also, we did

not code the behaviors if their initiator acted forcefully or

aggressively toward the recipient or if these behaviors were not

welcomed by the recipient (e.g., an initiator helped to place a

puzzle piece, but the recipient wanted to complete the puzzle

by him- or herself without help).

Reliability

After extensive training, the first author and one research

assistant independently coded 75 randomly selected sessions

(i.e., 75 5 minutes) to assess coding reliabilities. Kappa co-

efficients were as follows: hand to body, .71; body to body,

.70; talking, .81; show, .75; approach, .78; look, .73; object

offering, .84; helping, .75.

We calculated the sum of the frequencies of all six affiliative

behaviors that occurred in dyads and used this sum in further

analyses because internal consistency was moderately good

(Cronbachs alpha = .75 [3A], .73 [3B], .79 [4A], .72 [4B]).

INTERNATIONAL JOURNAL OF BEHAVIORAL DEVELOPMENT, 2008, 32 (2), 8997 91


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Friendship

The head teacher of each class was asked to nominate each

childs friend(s) because sociometric measures are generally

less reliable with children younger than 4 years (Hymel, 1983).

The teacher could nominate multiple numbers of friends and

was allowed to nominate no child when the teacher believed

that a given child did not have any friends. We defined two

children as a friend pair only when each was nominated as

being a friend to the other by the teacher. That is, we did not

define a unidirectional dyad, in which the teacher nominated

child X as a friend of child Y but did not nominate child Y as

a friend of child X, as a friend pair. Based on this definition,a child could be a member of more than one friend pair (range

of the number of friends identified per child: 06 [3A]; 27

[3B]; 15 [4A]; 16 [4B]). Nineteen, 24, 20, and 21 pairs were

reciprocally nominated in Classes 3A, 3B, 4A, and 4B, respec-

tively (16 boyboy pairs and 3 girlgirl pairs [3A]; 10 boyboy

pairs, 9 girlgirl pairs, and 5 boygirl pairs [3B]; 17 boyboy

pairs and 3 girlgirl pairs [4A]; and 3 boyboy pairs, 11

girlgirl pairs, and 7 boygirl pairs [4B]).

Analysis

Descriptive statistics. To investigate the age differences in

frequencies of affiliative and prosocial behaviors that occurred

within dyads, we used a generalized linear mixed model

(GLMM; Schall, 1991). Mixed models allow both fixed and

random terms to be fitted to the model. Fixed terms examine

its effects on the dependent variable. Random terms are used

to represent subject-specific (i.e., a dyad in the present study)

random variation and take into consideration repeated

sampling within the same individuals or groups (Crawley,

2002; Schall, 1991). In the model, we included frequencies of

affiliative or prosocial behaviors that occurred within dyads as

a dependent variable with a Poisson error structure, the age of

dyads as an independent variable, and dyads themselves as a

random term. By fitting the random term to the model, we

could resolve the problems of data dependency caused by the

longitudinal sample of 3B and 4B (i.e., the same dyads were

observed in 3B and in 4B) and the fact that the same child

could be a member of more than one dyad in each class.

Reciprocity and interchange. We used the matrix correlation

test (hereafter, Kr test) to examine reciprocity and interchange.

The Kr test enabled us to analyze whether individuals direct a

given type of behavior relatively more (or less) toward social

partners according to the extent that they receive more (or less)

of that behavior from the partners. The Kr test was developedfrom Kendalls tau approach and was a special version of

Mantels randomization test (Hemelrijk, 1990a). We used

Hemelrijks (1990a) permutation computer program

(MATSQUAR software) for the Kr test. First, we constructed

two actorreceiver matrices of social interactions. The values

of cells in the matrices represent the frequencies of behaviors

from an actor to a receiver. All cells in one matrix corre-

sponded to cells in the other matrix.The Kr test statistic (here-

after, Tau Kr) is calculated from within-row comparisons

between corresponding cells in two matrices (Hemelrijk,

1990a, 1990b). This statistic considers whether the change

between the two cells within one row in one matrix is in the

same direction as the change between the corresponding cells

in the other matrix. Tau Kr is the sum of the number of pairs

of cells whose change is in the same direction in two matrices

minus the number of pairs of cells whose change is in the

opposite direction in two matrices, while taking into account

the pairs of cells in which values neither increased nor

decreased (see Hemelrijk, 1990a, 1990b for details and

example computation). We calculated the Tau Kr between the

two matrices of the original (i.e., observed) data. Next,

MATSQUAR randomly permutated one of the two matrices,

while keeping the other matrix unchanged. The order of the

individuals in the rows was kept identical to that in the columns

to preserve the diagonal. We then calculated Tau Kr from these

two matrices. This permutation procedure was repeated to

produce the distribution of Tau Kr, which enabled reliablejudgment of thep-value of the Tau Kr from the original data.

In this article, we conducted 5000 permutations, which is a

realistic minimum for estimating a significance level of about

.01 (Manly, 1997). Finally, the one-tailed p-value of Tau Krfrom the original data was calculated by computing the

percentage of all permutations that yielded a Tau Kr equal to

or greater than the Tau Kr calculated from the original data.

Based on this percentage, we assessed the significance of the

results; if the percentage of the Tau Kr from the original data

fell within the rightmost 5% of the distribution, we regarded

the association between the two matrices as statistically signifi-

cant. In Kr tests, only the right-sided one-tailed probability

value was used; the left-sidedp-value was meaningless because


Table 1

Descriptions of coded affiliative and prosocial behaviors

Affiliative behaviors

Hand to body

A child spontaneously and gently touched his/her partners body,

including the partners hands, and then released the partner.

Body to body

A child spontaneously and gently clung to his/her partners bodyand then let go of the partners body.

Talking

A child spontaneously talked to his/her partner, excluding verbal

aggression (e.g., insults, derogatory comments). An instance of a

childs talking was considered to end when the child stopped

talking and started doing something else.

Show

A child spontaneously showed an object or his/her actions (e.g., a

toy, a book, or his/her own dancing) to his/her partner.

Approach

A child spontaneously approached within 1 m of a partner,

excluding cases in which the child accidentally approached his/her

partner.

Look

A child looked at his/her partner, excluding staring in an

unfriendly or angry manner.

Prosocial behaviors

Object offering

A child spontaneously gave objects (e.g., a toy) to his/her partner.

Helping

A child spontaneously assisted his/her partner to accomplish the

partners goal (e.g., putting on a smock, doing up buttons, holding

a ramp for another child during a racing car game, or pulling the

partner in a wagon while playing a firefighter game).


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it indicated the opposite of reciprocity/interchange (Hemelrijk,

1990a).

The Kr test has many advantages beyond intracorrelation

tests. First, the Kr test is robust to data in which there are

considerable individual differences in the frequencies of a

behavior or a considerable variation in frequencies between

behaviors (Hemelrijk, 1990a). This is because the Kr test

consists of within-row (i.e., within-individual) comparisons

that consider only the direction of the changes between two

cells in one row in one matrix and the direction change

between its corresponding cells in the other matrix. Because of

this advantage, the Kr test is also robust to a few extreme values

(i.e., outliers), which may have strongly biased the results of

other tests. The Kr test procedure (i.e., randomly permuting

one of the two matrices a considerable number of times and

computing the Tau Kr statistic each time) could resolve the

problem of non-independence of dyads that might arise when

analyzing dyadic interactions within a social interaction matrix

(Hemelrijk, 1990a; Manly, 1997; Sokal & Rohlf, 1995). In

addition, the random permutation procedure in the Kr test

could resolve the problems of unknown sampling distributions

of dyadic values because a sufficiently large number of random

permutations can generate a distribution of Tau Kr with whichthe significance of the Tau Kr from the original observed data

can be assessed (Hemelrijk, 1990a; Manly, 1997).

Using the Kr test, we first examined whether children recip-

rocated and interchanged prosocial behavior.We examined: (a)

the correlation between object offering from child X to child

Y and object offering from child Y to child X; (b) the correla-

tion between helping from child X to child Y and helping from

child Y to child X; (c) the correlation between object offering

from child X to child Y and helping from child Y to child X;

and (d) the correlation between helping from child X to child

Y and object offering from child Y to child X.

MATSQUAR enabled us to examine relationships between

two matrices after controlling for the effect of the third matrix

(Hemelrijk, 1990b). Using this, we examined whether children

reciprocate the partners prosocial behavior regardless of the

frequency of affiliation with the partner. We examined: (a) the

reciprocity of object offering, partialling out the frequency of

the affiliation in a dyad; and (b) the reciprocity of helping,

partialling out the frequency of the affiliation in a dyad.

If we found a significantly positive association between the

frequencies of the two types of prosocial behavior exchanged

within a dyad, this would not necessarily mean that the

children interchanged the different types of prosocial behavior

because it is not clear whether the received prosocial behavior

was reciprocation for the same behavior previously performed

by the recipient (i.e., reciprocity) or reciprocation for a differ-

ent type of prosocial behavior previously performed by therecipient (i.e., interchange), unless the frequency of the same

prosocial behavior by the recipient was controlled for. For

example, child X and child Y could have offered each other

objects with similar frequency, and child X could have helped

child Y with a predominant frequency. In such a case, the

matrix correlation test might detect a positive relationship

between the frequency of helping from child X to child Y and

the frequency of object offering from child Y to child X.

However, this correlation would likely be a by-product of the

reciprocity of the object offering between child X and child Y.

Thus, to investigate the interchanges between different types

of prosocial behavior, it was necessary to partial out the

frequency of one type of prosocial behavior and see whether

interchanges were independent from reciprocity between each

dyad. To do so, we examined: (a) the interchange between

object offering from child X to child Y and helping from child

Y to child X, controlling for helping from child X to child Y;

and (b) the interchange between helping from child X to child

Y and object offering from child Y to child X, controlling for

object offering from child X to child Y. To test whether the

interchanges were independent of the affiliation frequency of

dyads, we ran separate analyses in which the frequency of affili-

ation was partialled out by placing it within a third matrix when

investigating the correlations between object offering and

helping.

Reciprocity between fr iends versus non-friends. The Kr test eval-

uates the existence of reciprocity at classroom level but it does

not investigate the reciprocity at dyadic level (Silk et al., 1999).

To quantify the degree of reciprocity within dyads, we used an

improved version of Silk et al.s (1999) Reciprocity Index.

Consider a dyad of two individuals in which one initiated a

behavior s times and the other d times (s > d). In total, the

behavior within the dyad occurred N times (s + d= N). We

refer to the cumulative binomial probability ofs inNevents as

Sand that for dinNevents as D.Silk et al.s (1999) Reciprocity Index was calculated as D

divided by S. The reciprocity index approached 0 when inter-

actions within a dyad were due primarily to one of the two

individuals; it approached 1 when interactions were due evenly

to the two participants. A weakness of Silk et al.s (1999) Reci-

procity Index is that it may fraudulently detect a high level of

dyadic reciprocity when examining dyads in which very few or

no social exchanges occurred.

Therefore, we modified the Reciprocity Index of Silk et al.

(1999) as follows: (0.5/S 0.5) 2. This formula is based on

the fact that the cumulative binomial probability of one indi-

vidual in a dyad is 0.75 if two children exchange a prosocial

behavior with each other, one time. The cumulative binomial

probability gradually approaches 0.5 if two children exchange

prosocial behaviors with each other exactly the same number

of times which is close to an infinite number. Therefore, we

could incorporate the frequency of prosocial behavior by

dividing 0.5 by S. In addition, we subtracted 0.5 and multi-

plied by 2, so that this value ranges from 0 (unbalanced

exchanges) to 1 (complete reciprocation). The value for a dyad

in which balanced exchanges occurred is higher than for a dyad

in which less balanced exchanges occurred. This value has an

advantage over the Silk et al. (1999) Reciprocity Index because

it reflects the degree of reciprocity taking account of the total

frequency of a behavior that occurred in a dyad. For example,

the value is 0.33 when two individuals in a dyad did a behavior

to each other one time (i.e., the behavior occurred two timesin total); it is 0.52 when two individuals in a dyad did a

behavior to each other three times (i.e., the behavior occurred

six times in total). This indicates that the latter dyad was more

reciprocal than the former dyad. Hereafter, we call this value

the Modified Reciprocity Index (MRI).We excluded MRIs of

dyads in which offering/helping occurred one or less times

from the analyses because it is meaningless to examine the

degree of reciprocity in those dyads.

Means and standard deviations of MRIs of offering and

of helping per dyad in each class were calculated (Table 2).

We used the GLMM to investigate the age differences in

MRIs. As in testing the age differences in frequencies of affilia-

tive or prosocial behaviors, we included MRIs of dyads as a



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dependent variable with a binomial error structure, age of

dyads as an independent variable, and dyads themselves as a

random term. We examined the age difference in MRIs of

offering and of helping in separate analyses.

To examine the hypothesis that preschool children adjust the

quantity of reciprocation toward a partners object offering or

helping behavior according to their friendship, we used a

GLMM that included MRIs of dyads as a dependent variable

with a binomial error structure, friendship status (friend or

non-friend) of dyads as an independent variable, and dyads

themselves as a random term. Children could have had more

than one friend, creating non-independency in the MRI data.

However, as stated earlier, the problems of pseudoreplication

and data dependency were resolved by fitting the dyads them-

selves as a random term in the GLMM.

Results

Descriptive data

Table 2 presents the means and standard deviations of affilia-

tive or prosocial behaviors within dyads by class (the number

of the possible dyads in a class: 3A, n = 91; 3B, n = 120; 4A,

n = 66; 4B, n = 120). GLMM showed no age differences in

the frequencies of affiliative or prosocial behaviors occurring

in dyads (Table 3).

Reciprocity and interchange

Table 4 presents Kr test statistics for the reciprocity of object

offering and reciprocity of helping in all classes. The relative

amounts of object offering were significantly correlated with

the relative amounts of object offering received in all classes.

Similarly, the relative amounts of helping were significantly

correlated with the relative amounts of helping received in all

classes, apart from Class 3A, for which the result approachedsignificance. Moreover, the reciprocity of object offering for all

classes was confirmed when the number of affiliative acts was

partialled out, which suggests that reciprocity of object offering

was independent of the affiliative interactions in a dyad.Reciprocity of helping, with the frequency of the affiliative

interaction in a dyad partialled out, was confirmed in Class 3B

and Class 4B.This trend in Class 4A class approached signifi-

cance, but was not significant in Class 3A (Table 4).

Kr tests demonstrated the interchange between object

offering and helping in all classes (Table 4). Interchange

between object offering and helping was independent of the

reciprocity of each prosocial behavior in 4-year-olds but not in

3-year-olds. The correlation between the relative amounts of


Table 2

Mean and standard deviations for the frequencies of total

affiliative or prosocial behaviors within dyads and Modified

Reciprocity Indexes

3A 3B 4A 4B

Mean Mean Mean Mean

(SD) (SD) (SD) (SD)

Affiliative behaviors 50.55 49.67 53.76 57.31

(43.99) (35.18) (48.38) (63.07)

Prosocial behaviors

Object offering 2.03 3.16 2.55 2.61

(3.40) (3.97) (3.16) (3.82)

Helping 0.73 1.13 0.73 1.54

(1.19) (2.07) (1.38) (3.28)

Modified Reciprocity Index

Object offering 0.12 0.12 0.14 0.13

(0.16) (0.16) (0.14) (0.17)

Helping 0.05 0.08 0.12 0.11

(0.09) (0.12) (0.20) (0.15)

Note. Standard deviations are in parentheses.

Table 3

Results of generalized linear mixed modeling for age comparisons

of the frequencies of affiliative or prosocial behaviors within dyads,

and Modified Reciprocity Indexes

Beta SE df t

Affiliative behaviors

Age (3 years vs. 4 years) 0.02 0.08 395 0.30+

Prosocial behaviors

Object offering


Helping


Modified Reciprocity Index

Object offering


Helping


Note. Separate analyses were conducted.+p < .1; **p < .01; ***p < .001.

Table 4

Results of Kr tests: reciprocity of object offering, reciprocity of

helping, and those with controlling affiliation frequency in a dyad;

interchange between object offering and helping, interchange with

controlling initiations of each prosocial behavior, and interchange

with controlling affiliation frequency in a dyad.The Kr test

statistics (Tau Kr) were reported

3A 3B 4A 4B

Reciprocity

Object offering 0.25*** 0.24*** 0.42*** 0.43***

Affiliation controlled 0.16* 0.14** 0.25** 0.26***

Helping 0.12+ 0.21*** 0.26*** 0.28***

Affiliation controlled 0.03 0.16** 0.16+ 0.15*

Interchangea

Object offering/helping 0.15* 0.14* 0.23** 0.29***

received

Initiation of helping 0.12+ 0.08 0.15* 0.21***

controlled

Affiliation frequency 0.05 0.06 0.08 0.12*

controlled

Helping/object offering 0.16* 0.16** 0.28** 0.27**

received

Initiation of object 0.06 0.09+ 0.15* 0.11*

offering controlled

Affiliation frequency 0.07 0.09 0.16* 0.12*

controlled

Note. +p < .1; *p < .05; **p < .01; ***p < .001.a Initiation of each prosocial behavior and the affiliation frequency

were controlled in separate analyses.


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object offering and the relative amounts of helping received

was significant when the relative amounts of helping were

partialled out in classes of 4-year-olds. This correlation

approached significance in Class 3A, but not in 3B.The corre-

lation between the relative amounts of helping and the relative

amounts of object offering received was significant when the

relative amounts of object offering were partialled out in

classes of 4-year-olds.This correlation approached significance

in Class 3B, but not in 3A.

When affiliation frequency in a dyad was partialled out,

there was a significant correlation between object offering and

helping received in one class of 4-year-olds (4B). Interchange

between helping and object offering received, with affiliation

frequency in a dyad partialled out, was confirmed in two

classes of 4-year-olds but was not in the 3-year-olds (Table 4).

Reciprocity between friends versus non-friends

Table 2 presents means and standard deviations of the MRIs

of dyads for offering and helping by class.The GLMM showed

that MRIs of object offering did not differ according to age,

whereas the MRI of helping in 4-year-olds tended to be higher

than for 3-year-olds (Table 3).The GLMM also indicated that the MRI of offering was

significantly higher for friends, mean (SD) = 0.19 (0.18), than

for non-friends, mean (SD) = 0.10 (0.14). However, the MRI

of helping was not different between friends, mean (SD) =

0.11 (0.14) and non-friends, mean (SD) = 0.08 (0.14)

(Table 5).

Discussion

In this study, we conducted naturalistic observations in same-

age peer groups of 3- and 4-year-olds and found positive corre-

lations between the frequencies of helping given and received

and the frequencies of object-offering given and received

within dyads. This suggests that Japanese preschool children

reciprocate prosocial behavior. This result is consistent with

previous experimental studies reporting that children who

received more prosocial behavior from a partner in previous

sessions directed more prosocial behavior toward that partner

in subsequent sessions, while children who received less from

a partner in previous sessions directed less to their partner in

ongoing sessions (Birch & Billman, 1986; Peterson,

Hartmann, & Gelfand, 1977; Staub & Sherk, 1970). Our

results reinforce the findings from observational studies that

used simple correlation tests (Strayer, 1980). Because the Krtest has several important advantages over ordinary correlation

tests when using dependent data with unknown sampling

distributions and data with variations in individual behavioral

frequency (Hemelrijk, 1990a), our study also provides more

precise evidence of reciprocity among preschoolers.The social

relations model (Kenny, 1994; Kenny & La Voie, 1984),

another statistical method that has been used to examine

dyadic reciprocity (Card, Hodges, Little, & Hawley, 2005;

Cook, 2001; Ross & Lollis, 1989; Ross, Stein, Trabasso,

Woody, & Ross, 2005; Stevenson, Leavitt, Thompson, &

Roach, 1988), also considers the data dependency of social

interaction within dyads and individual differences in behavior.

The Kr test has a compensatory function to the social relations

model as the Kr test allows examination of the association

between two matrices controlling for the effect of the third

matrix (e.g., the frequency of affiliation within dyads; see

Hemelrijk, 1990b).

It is possible that reciprocity of prosocial behavior was

affected by affiliative interaction among peers, a concern that

was not addressed in previous studies. In our study, we found

that reciprocity of object offering was confirmed in all classes,

even after controlling for the frequency of affiliative inter-

action. Reciprocity of helping was also confirmed in all classes

when controlling for affiliation, except in one class of 3-year-olds. These results suggest that preschool-age children do not

simply direct prosocial behavior toward those with whom they

are frequently affiliated, but that they reciprocate selectively to

peers from whom they receive prosocial behavior.

It is known that infants and toddlers show a prototype of

reciprocity. For example, even 6-month-old infants reciprocate

physical contact (Hay et al., 1983), while 2-year-olds show

reciprocity of contributions to positive interactive sequences

(Ross & Lollis, 1989). These findings suggest that even very

young children may socially influence their peers.However, the

age around which young children begin to show spontaneous

reciprocity of prosocial behaviors has remained unknown. For

example, it has been reported that 2-year-old children showed

reciprocity of offering when their mothers requested that they

do so (Levitt et al., 1985). However, it is unknown whether

2-year-olds show this reciprocity without their mothers

encouragement. Naturalistic observations of mixed-age groups

of 3-year-olds have revealed reciprocity in 3- and 4-year-olds

(Strayer, 1980; Strayer et al., 1979). However, it was unclear

whether the 3-year-olds spontaneously reciprocated in those

studies because elder children might have encouraged them to

do so. Because this study focused on natural situations within

same-age classes, it can now be said conclusively that 3-year-old

children show spontaneous reciprocity of prosocial behavior.

This study demonstrates that children interchange different

types of prosocial behavior; the Kr test also revealed a signifi-

cant correlation between object offering and the receipt ofhelping and a correlation between helping and the receipt of

object offering for all classes. This suggests that preschool

children reciprocated their partners prosocial behavior with

not only a similar action, but also by using a different form of

prosocial act. Based on the fact that: (a) the correlation

between object offering from child X to child Y and helping

from child Y to child X was significant after controlling for

helping from child X to child Y, and (b) the correlation

between helping from child X to child Y and object offering

from child Y to child X was also significant when object

offering from child X to child Y was controlled in 4-year-olds,

we can say that the interchange between offering and helping

was independent of the reciprocity within object offering and


Table 5

Results of generalized linear mixed modeling for friendnonfriend

comparisons of the Modified Reciprocity Indexes

Beta SE df t

Object offering

Friend versus non-friend 0.51 0.20 196 2.55*

Helping

Friend versus non-friend 0.28 0.36 87 0.77*

Note. Separate analyses were conducted.

*p < .05; ***p < .001.


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the reciprocity within helping in 4-year-olds. The interchanges

were not confirmed in 3-year-olds after controlling for other

types of prosocial behavior. This suggests that the recipients

reciprocated a partners prosocial behavior regardless of the

type of prosocial behavior in 4-year-olds. The original recipi-

ent of prosocial behavior may not need to return the favor in

the same way as it was received. Rather, they may return

partners favors using different forms of prosocial behavior that

might be more appropriate for their partner in a different situ-

ation (Eisenberg & Fabes, 1998). Gouldner (1960) argued that

individuals do not necessarily reciprocate the favor of the social

partner with a favor of the same form, but may reciprocate with

a favor of a different form that has similar value to the

received favor. Likewise, 4-year-olds may interchange the

partners former favor with a different form of prosocial

behavior regarded as having a similar value. These results

showed more complex types of social exchange occurring than

were previously known because past studies simplified social

exchange among children by pooling all types of prosocial

behavior (Strayer, 1980; Strayer et al., 1979).

Analyses of reciprocity are fundamentally different from

analyses of individual differences in social behavior or on

differential allocation of social behavior according to theidentity of social partners.This is because the former analyses

consider the balance between the frequencies of social

behavior exchanged in a dyad, whereas later analyses do not.

Therefore, studies of reciprocity have the potential to provide

novel knowledge about social relationships in children. For

example, analyses of reciprocity may enable us to distinguish

friendships with mutual preference from those with unilateral

preference (Rubin et al., 1998). The present study quantified

the degree of reciprocation using the MRI based on Silk et al.s

(1999) Reciprocity Index and found that the MRI for object

offering was higher for dyads of friends than for dyads of non-

friends. This result means that preschool children reciprocate

with their friends in a more balanced way than with non-

friends, suggesting that preschool children adjust the degree of

reciprocity according to friendship.This may be one of the

ways in which preschoolers regulate or maintain their relation-

ships (Hartup, 1995). Despite awareness that reciprocity is

central within childrens friendships (Bukowski & Sippola,

1996; Rubin et al., 1998), few studies have investigated the link

empirically (Dreman & Greenbaum, 1973; Leiter, 1977; Levitt

et al., 1985). Our findings empirically support the link between

reciprocity and friendship. In addition, our findings emphasize

the importance of the quantitative analysis of reciprocity, such

as by using the MRI, although previous studies treated reci-

procity dichotomously (i.e., the occurrence of reciprocity vs.

nonoccurrence of reciprocity), which could oversimplify

exchanges of prosocial behavior (Dreman & Greenbaum,1973; Howes, 1983; Leiter, 1977; Levitt et al., 1985).

We did not find a difference between friends and non-friends

in the MRI for helping. This might be due to the fact that

children may sometimes help peers regardless of their friend-

ship (Berndt, 1981). Because children are particularly likely to

assist people who will clearly benefit from their assistance

(Eisenberg & Fabes, 1998), a difference between friends and

non-friends in terms of helping might not be observed.

The present study examined the developmental process of

reciprocity during the preschool period, an area that had not

been thoroughly examined in previous studies (see Youniss,

1986, for the developmental process during the elementary

school period). The 3- and 4-year-olds differed in terms of

interchanges that were independent of reciprocity of the same

behavior. While 4-year-olds interchanged between object

offering and helping independent of the reciprocity of each

prosocial behavior, this was not apparent in 3-year-olds. This

suggests that reciprocity becomes more complicated as

children grow older. In addition to the extent of accumulated

social experiences, it is possible that the age-related differences

in interchange between 3-and 4-year-olds run parallel with the

rapid development of sociocognitive abilities occurring around

this age period (Astington, 1993; Wellman, Cross, & Watson,

2001). That is, interchanges that are independent of reciproc-

ity would require reasoning to judge whether a childs favor to

his or her partner has similar value to the favor received from

the partner (Gouldner, 1960); they would also require the

ability to choose an appropriate behavior from a variety of

prosocial behaviors to satisfy the partners need and the social

context.

We had predicted that the effects of friendship on the degree

of reciprocity would increase in 4-year-olds relative to 3-year-

olds. However, this prediction was unsupported because

neither the MRI of offering nor that of helping was signifi-

cantly affected by age, and friendships affected only the MRI

of offering. This suggests that the adjustment for the degree ofreciprocation according to friendships did not differ between

3-year-olds and 4-year-olds, although studies on relationship

stability among preschoolers have reported that children over

age 4 show stable relationships, but children under this age fail

to show stability (Guralnick & Groom, 1988; Hymel, 1983;

Uehara, 2004). Perhaps the interval between age 3 and age 4

is too small to detect differential reciprocation based on friend-

ships according to age.

Furthermore, although there have been many studies of reci-

procity in western cultures (Birch & Billman, 1986; Levitt et

al., 1985; Staub & Sherk, 1970; Strayer, 1980; Strayer et al.,

1979), few studies have been conducted in eastern cultures.

Although comparing western and eastern reciprocity results is

beyond the scope of this study, our analysis may help to fill the

gap and provide an opportunity to discuss existing cultural

differences. For example, the results of this study may not be

universally found in western cultures. It is known that proso-

cial behavior of children is associated with socializing experi-

ences (Eisenberg & Fabes, 1998; Hay, 1994). Compared with

western cultures, Japanese culture is characterized by extensive

efforts to enhance the development of childrens prosocial

behavior (Stevenson, 1991). As a result, Japanese children are

given many more opportunities to learn prosocial behaviors

than children in western cultures. For example, the presence

of interchanges, which were not investigated in previous

studies from western cultures, may be attributable to cultural

differences. To examine whether there are any cultural influ-ences on prosocial behavior, it would be interesting to

investigate whether similar results would be obtained in

western societies, by using identical methodology and the new

statistical tests.

References

Astington, J.W. (1993). The childs discovery of the mind. Cambridge, MA:

Harvard University Press.

Berndt, T.J. (1981). Effects of friendship on prosocial intentions and behavior.

Child Development, 52, 636643.

Bigelow, B.J., & LaGaipa, J.J. (1975). Childrens written descriptions of friend-

ship: A multidimensional analysis. Developmental Psychology, 11, 857858.



10/10


Birch, L.L., & Billman, J. (1986). Preschool childrens food sharing with friends

and acquaintances. Child Development, 57, 387395.

Bukowski, W.M., & Sippola, L.K. (1996). Friendship and morality: (How) are

they related? In W.M. Bukowski, A.F. Newcomb, & W.W. Hartup (Eds.), The

company they keep. Friendship in childhood and adolescence (pp. 238261).

Cambridge: Cambridge University Press.

Card, N.A., Hodges, E.V.E., Little, T.D., & Hawley, P.H. (2005). Gender effects

in peer nominations for aggression and social status. International Journal of

Behavioral Development, 29, 146155.

Cook, W.L. (2001). Interpersonal influence in family systems: A social relations

model analysis. Child Development, 72, 11791197.Crawley, M.J. (2002). Statistical computing: An introduction to data analysis using

S-Plus. Chichester: Wiley.

Dreman, S.B., & Greenbaum, C.W. (1973). Altruism or reciprocity: Sharing

behavior in Israeli kindergarten children. Child Development, 44, 6168.

Dunn, J. (2004). Childrens friendships.The beginning of intimacy. Oxford: Black-

well.

Dunn, J., & Slomkowski, C. (1992). Conflict and the development of social

understanding. In C.U. Shantz & W.W. Hartup (Eds.), Conflict in child and

adolescent development(pp. 7092). Cambridge: Cambridge University Press.

Eisenberg, N., Cameron, E., Tryon, K., & Dodez, R. (1981). Socialization of

prosocial behavior in the preschool classroom. Developmental Psychology, 17,

773782.

Eisenberg, N., & Fabes, R.A. (1998). Prosocial development. In W. Darmon &

N. Eisenberg (Vol. Eds.), Handbook of child psychology:Vol. 3. Social, emotional,

and personality development(5th ed., pp. 701778). New York: Wiley.

Eisenberg, N., Lundy, T., Shell, R., & Roth, K. (1985). Childrens justifications

for their adult and peer-directed compliant (prosocial and nonprosocial)behaviors. Developmental Psychology, 21, 325331.

Goodnow, J.J., & Burns, A. (1985).A childs eye. Sydney: Alwin.

Gouldner, A.W. (1960). The norm of reciprocity: A preliminary statement.

American Sociological Review, 25, 161178.

Guralnick, M.J., & Groom, J.M. (1988). Friendships of preschool children in

mainstreamed playgroups. Developmental Psychology, 24, 595604.

Hartup, W.W. (1995). Cooperation, close relationships, and cognitive develop-

ment. In W.M. Bukowski, A.F. Newcomb, & W.W. Hartup (Eds.), The

company they keep. Friendship in childhood and adolescence (pp. 213237).

Cambridge: Cambridge University Press.

Hay, D.F. (1994). Prosocial development. Journal of Child Psychology and

Psychiatry, 35, 2971.

Hay, D., Nash, A., & Pederson, J. (1981). Responses of six-month-olds to the

distress of their peers. Child Development, 52, 10711075.

Hay, D., Nash, A., & Pederson, J. (1983). Interaction between six-month-old

peers. Child Development, 54, 557562.Hemelrijk, C. (1990a). Models of, and tests for, reciprocity, unidirectionality,

and other social interaction patterns at group level. Animal Behaviour, 39,

10231029.

Hemelrijk, C. (1990b). Matrix partial correlation test used in investigations of

reciprocity and other social interaction patterns at a group level. Journal of

Theoretical Biology, 143, 405420.

Hinde, R.A. (1979). Towards understanding relationships. London: Academic

Press.

Hinde, R.A., & Stevenson-Hinde, J. (1987). Interpersonal relationships and

child development. Developmental Review, 7, 121.

Howes, C. (1983). Patterns of friendship. Child Development, 54, 10411053.

Howes, C. (1987). Peer interaction of young children.Monographs of the Society

for Research in Child Development, 53 (1, Serial No. 217).

Hymel, S. (1983). Preschool childrens peer relations: Issues in sociometric

assessment.Merr ill-Palmer Quarterly, 29, 237260.

Kenny, D.A. (1994). Interpersonal perception: A social relations analysis. New York:

Guilford Press.Kenny, D.A., & La Voie, L.J. (1984).The social relations model. In L. Berkowitz

(Ed.), Advances in experimental social psychology (Vol. 18, pp. 142182). San

Diego, CA: Academic Press.

Laursen, B., & Bukowski, W.M. (1997). A developmental guide to the organisa-

tion of close relationships. International Journal of Behavioral Development, 21,

747770.

Laursen, B., & Hartup, W.W. (2002). The origins of reciprocity and social

exchange in friendships.New Direc tions for Child and Adolescent Development,

95, 2740.

Leiter, M.P. (1977). A study of reciprocity in preschool play groups. Child

Development, 48, 12881295.

Levitt, M.J., Weber, R.A., Clark, M.C., & McDonnell, P. (1985). Reciprocity of

exchange in toddler sharing behavior.Developmental Psychology, 21, 122123.

Manly, B.F. (1997). Randomization, bootstrap and Monte Carlo methods in biology.Texts in statistical science (2nd ed.). London: Chapman & Hall.

Peterson, L., Hartmann, D.P., & Gelfand, D.M.(1977). Developmental changes

in the effects of dependency and reciprocity cues on childrens moral judg-

ments and donation rates. Child Development, 48, 13311339.

Ross, H.S., Cheyne, A., & Lollis, S.P. (1988). Defining and studying reciproc-

ity in young children. In S.W. Duck (Ed.), Handbook of personal relationships

(pp. 143160). Chichester: Wiley.

Ross, H., & Lollis, S. (1989). A social relations analysis of toddler peer relation-

ships. Child Development, 60, 10821091.

Ross, H., Stein, N., Trabasso, T., Woody, E., & Ross, M. (2005).The quality of

family relationships within and across generations: A social relations analysis.

International Journal of Behavioral Development, 29, 110119.

Ross, H., Tesla, C., Kenyon, B., & Lollis, S. (1990). Maternal intervention in

toddler peer conflict: The socialization of principles of justice. Developmental

Psychology, 26, 9941003.

Rubin, K.H., Bukowski, W., & Parker, J.G. (1998). Peer interactions, relation-

ships, and groups. In W. Darmon & N. Eisenberg (Vol. Eds.), Handbook ofchild psychology:Vol. 3. Social, emotional, and personality development(5th ed.,

pp. 619700). New York: Wiley.

Schall, R. (1991) Estimation in generalized linear models with random effects.

Biometrika, 78, 719727.

Silk, J.B., Seyfarth, R.M., & Cheney, D.L. (1999). The structure of social

relationships among female savanna baboons in Moremi Reserve, Botswana.

Behaviour, 136, 679703.

Sokal, R.R., & Rohlf, F.J. (1995). Biometry:The principles and practice of statistics

in biological research (3rd ed.). New York: Freeman.

Staub, E., & Sherk, L. (1970). Need for approval, childrens sharing behaviors

and reciprocity in sharing. Child Development, 41, 243252.

Stevenson, H.W. (1991).The development of prosocial behaviour in large-scale

collective societies: China and Japan. In R.A. Hinde & J. Groebel (Eds.),

Cooperation and prosocial behaviour (pp. 89105). Cambridge: Cambridge

University Press.

Stevenson, M.B., Leavitt, L.A., Thompson, R.H., & Roach, M.A. (1988). Asocial relations model analysis of parent and child play. Developmental Psychol-

ogy, 24, 101108.

Strayer, F.F. (1980). Child ethology and the study of preschool social relations.

In H.C. Foot, A.J. Chapman, & J.R. Smith (Eds.), Friendship and social

relations in children (pp. 235265). New York: Wiley.

Strayer, F.F., Wareing, S., & Rushton, J.P. (1979). Social constraints on natu-

rally occurring preschool altruism. Ethology and Sociobiology, 1, 311.

Trivers, R.L. (1971). The evolution of reciprocal altruism. Quarterly Review of

Biology, 46, 3557.

Uehara, I. (2004). Developmental changes in consistency of preferential feeling

for peers and objects around age four. Psychological Reports, 94, 335347.

Wellman, H.M., Cross, D., & Watson, J. (2001). Meta-analysis of theory-

of-mind development: The truth about false belief. Child Development, 72,

655684.

Youniss, J. (1986). Development in reciprocity through friendship. In C. Zahn-

Waxler, M. Cummings, & R. Iannotti (Eds.), Altruism and aggression

(pp. 88106). Cambridge: Cambridge University Press.

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