Download Individual, dyadic and network effects in friendship

GENUS, LXVII (No. 3), 1-27
GIULIA RIVELLINI* – LAURA TERZERA** – VIVIANA AMATI***
Individual, dyadic and network effects in friendship
relationships among Italian and foreign schoolmates
1. INTRODUCTION
The foreign presence in Italy is by now a well-consolidated and continuously growing phenomenon. Between 1990 and 2008, this presence - both
legal and illegal - has more than tripled. According to estimates, in 1990 there
were 1,144,000 foreigners; in 2008, 4.3 million (Fondazione ISMU, 2010).
More than 95% of them come from countries with high emigration levels
(CHEL1). The presence of foreigners was and still is not uniform throughout
the country. The destination of most migration flows, either directly or as a
result of mobility once in the country, is northern Italy. On January 1st, 2010 as
many as 61.6% of foreigners were living in the North, one quarter in central
Italy and only 13.1% in the South (Istat, 2010).
In addition, migration in Italy is usually definitive, as evidenced by an
increasing presence of families and minors (Terzera, 2010). The latter, for
example, accounted for less than 3% of total resident minors in 2003 and
increased to 9.1% in 20092. Minors who joined their parents already living in
Italy increased from nearly 3,000 in the early 1980s to 40,000 in 2006.
Another example of the transformation of the migrant contingent into a
population is the growing number of children born of at least one foreign parent: if “only” 6,000 children were born to foreign parents in 1992, this number
has risen to more than 77,000 in 2009, accounting for 13.6% of total newborns
in Italy. The growing presence of foreign minors, especially from 2000
onwards, can also be attested to by the increase in foreign pupils attending Italian public schools (Figure 1).
The process of settlement is a fairly recent event in Italy, since the heaviest immigration flows have occurred in the past 20 years. Therefore the immi*Dipartimento di Scienze Statistiche, Università Cattolica del Sacro Cuore, Milano, Italy.
** Dipartimento di Statistica, Università Milano Bicocca, Milano, Italy.
*** Department of Computer and Information Science, University of Konstanz, Konstanz,
Germany.
Corresponding author: Giulia Rivellini; e-mail: [email protected].
1
This definition includes countries which are part of the special aggregate “LDR, Less Developed Regions” used by the UN, as well as East Europe, which is considered part of the MDR –
More Developed Regions (http://esa.un.org/unpd/wpp/Excel-Data/definition-of-regions.htm).
2
All the data presented in this section are official and provided by the National Institute for Statistics (www.demo.istat.it) or by the Minister of Research and Education (www.miur.it).
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GIULIA RIVELLINI – LAURA TERZERA – VIVIANA AMATI
grants’ children3 are the first generation of foreign people, who are partially or
totally growing in Italy. Because of this situation, in Italy at present there is a
near-concurrence between immigrants’ children and minors. Thus we have the
opportunity to study migrant children at ages which are critical for the formation of their personalities.
Figure 1 – Pupils with non-Italian citizenship. 2001/02-2008/09
Source: Miur, several years.
Studying immigrants’ children is important, above all, to understanding the
level of integration of the immigrant population. The experience of those countries with a long history of migratory inflows suggests that, in fact, integration is
possible in the first generation but more likely in the second and in the later generations (Crul et al., 2003; Farina et al., 2007; Thomson et al., 2007).
Several aspects can be taken into account to measure or give an indication of the integration level of the descendants of the immigrants. These
include the construction of identity (affected by regulation regarding citizenship), employment and training opportunities, culture, lifestyle, social settings
and relationships.
This paper has been developed based on the awareness that among all the
factors useful for empirically describing the integration process, the analysis of
peer networks reveals a perspective that has not yet been widely explored in
Italy and is full of interesting implications (Rivellini, 2007; Gilardoni, 2008;
Casacchia et al., 2009; Amati, 2009).
One of the settings where friendship relationships among teenagers develop is undoubtedly the school (compulsory in Italy until the age of 16) which
3
This group includes second generations (i.e. children born in Italy of foreign parents) as well as
the so-called generations 1.25, 1.5 e 1.75 (see Rumbaut, 1994), that is to say those who arrived
in Italy before coming of age, when they were younger than 18.
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INDIVIDUAL, DYADIC AND NETWORK EFFECTS IN FRIENDSHIP RELATIONSHIPS
can also facilitate meeting of classmates outside school. In this age group, the
preferred friends are those with whom you can chat, start going out and confide the first secrets. On the other hand, the communication difficulties (not
only in terms of language) which limit the exchange and the possibility of
meaningful relationships with classmates may sometimes cause discrimination
and exclusion (Caneva, 2011). This might lead pupils to become even more
introverted. Therefore, if we consider the school as a training ground for social
relationships, exploring friendships outside of the school setting may provide
further insights as to children’s social integration level.
Our hypothesis is that the first generation of immigrants’ children finds it
more difficult to fit in because of a discriminatory attitude, generated in most
cases by migration being a relatively novel phenomenon in Italy.
However, as suggested by the literature, individual factors (i.e. migration
history) and/or structural factors, associated with the peer network within the
classroom, may either alleviate or worsen such difficulties.
For instance, relational data revealed the existence of discrimination
between black and white students in the USA and the important role of school
classes in the integration process (Hallinan et al., 1987; Moody, 2001). In the
Netherlands, several studies investigated the existence of ethnic boundaries
between Dutch children and their classmates of ethnic minorities (Lubbers,
2003; Baerveldt et al., 2004; Baerveldt et al., 2007; Lubbers et al., 2007; Vermeij, 2009) in friendship networks.
The opportunity theory4 considers school classes as the privileged place
where both foreign-born5 and Italian pupils get in touch, and foster inter-ethnic relationships.
Using the above-mentioned approaches and theories, in this paper we
want to study friendship networks and thereby highlight the state of segregation and marginalization of immigrant´s children in Italy. The following individual characteristics are considered essential in order to understand processes associated with the migratory phenomenon: gender, as suggested by psychological literature (Confalonieri et al., 2005; Petter, 2007), the area of origin
and socialization6.
4
The opportunity theory states that contacts within people of different ethnicity can reduced prejudices, increasing the chance of inter-ethnic relationships (Hallinan, 1982).
5
The origin of immigrants’ children is defined here as a function of the parents’ birthplace,
because in Italy the principle of ius sanguinis is applied as regards acquiring citizenship. For more
details, see Casacchia et al. 2008.
6
In this area of study, by socialisation we mean the process whereby information regarding the
cultural heritage of a community is passed on and internalized. For the analysis conducted here,
a distinction is made between individuals with complete Italian socialization (born in Italy or who
came here before starting school); partial Italian socialization (those who attended school both
abroad and for at least four years in Italy) and socialized “elsewhere” (i.e. arrived in Italy within
three years before the survey date).
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GIULIA RIVELLINI – LAURA TERZERA – VIVIANA AMATI
If, on the one hand, marginalisation is considered the absence of relationships with others, and segregation the prevalence of intra-ethnic relationships,
then social integration is defined here as the outcome of a behaviour which
places inter-ethnic relationships above intra-ethnic relationships.
Thus, from an analytical perspective, our hypothesis states that it is more
likely to observe a friendship relationship between pupils of foreign origin
than between an Italian and an immigrants’ child. To verify this hypothesis, we
jointly analyse the structural properties of friendship networks of lower secondary school classmates and their individual and migratory characteristics.
Data used were collected in 2006 in Lombardy - a region in the NorthWest of Italy - by Fondazione ISMU7 as part of the national project “ITAGEN2” . This region is interesting because: a) it is the region with the largest
population of foreigners (between one-fifth and one-quarter of the total population of foreigners); b) it is one of the regions in Italy where migration is more
consolidated (for example, with a large presence of immigrant families). The
focus on Lombardy can be illustrative for phenomena which will presumably
spread to the rest of Italy later on.
The paper is organized as follows: section 2 describes the data and
methodology, focusing on the choice of statistical network model; sections 3
and 4 present the descriptive evidence and estimates of the model parameters.
The last section contains some concluding remarks on new elements emerging
in regard of the topic and the methodology that was used.
2. DATA AND METHODS
2.1 Survey sample and friendship measurement
To learn more about immigrants’ children in Italy, a nationwide sample
survey was conducted in 2006 (ITAGEN2) - promoted by eight universities
with the support of local public and private agencies or foundations - on a subgroup of minors (Italian and foreign) in lower secondary school (Casacchia et
al., 2008). The choice of that target population was underpinned by two main
factors: these kids (pre-adolescent) are old enough (>11 years) to be able to
autonomously fill in a structured questionnaire requiring about one hour of
their time; and the chosen grade of the school is compulsory and precedes the
choice of whether to go on to senior high school. This transition point is important because already today there is evidence of significant differences between
Italian kids (many of whom choose to go on to senior high school) and foreignborn kids (who more typically choose a professional training school).
The survey sample of Lombardy consists of 17,277 pupils, both Italian
and children with at least one foreign parent (for more details of the national
7
ISMU, Iniziative e Studi sulla Multietnicità, www.ismu.org.
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INDIVIDUAL, DYADIC AND NETWORK EFFECTS IN FRIENDSHIP RELATIONSHIPS
sample structure see Dalla Zuanna, 2008). In this paper we consider only
pupils attending seventh and eighth grade (11,245 cases), because it is assumed
that friendships among classmates are consolidated by then. The questionnaire
of the national survey was divided into 7 sections, and included questions
about the demographic and social characteristics of the pupils and their relatives, as well as the future expectations and the free time of the children. An
additional part related to the collection of network variables (see below for a
detailed description) was added to the questionnaires handed out in Lombardy
and Lazio.
The information concerning kids´ free time allow us to analyse the existence and strength of the friendships of immigrant´s children (with Italians
and/or foreigners) outside school, and compute an indicator of the ‘friendship
strategy’ (Berry, 2001). The indicator is a combination of the answers to the
following four questions: do you have Italian friends? Do you have non-Italian friends? Do you see your Italian friends outside school? Do you see your
foreign friends outside school? Those who say that they have and see both Italian and foreign friends are defined as “integrated”, those who see only Italian
friends are considered “assimilated”; if the friends they have and see are mainly foreigners they are “segregated” and, finally, those who have neither Italian
nor foreign friends are classified as “marginalized”8.
This preliminary part refers to questions which do not precisely define the
type of tie (e.g. by defining it as a parental bond or one deriving from being
part of the same sports team or association, or chosen friendships), nor allow
us to identify the persons as friends, thus preventing a measurement of the reciprocity, homophily and balance effect in the relationships. For the sake of
clarity, let us consider Figure 2. Reciprocity (Wasserman et al., 1994;
Baerveldt et al., 2004; Scott, 2007) involves pairs of actors and represents the
tendency that both the ties from Ego to Alter and from Alter to Ego are present (Figure 2a9). In terms of friendship, reciprocity suggests that two actors
named each other as a friend. Homophily can be described using the adage
“birds of a feather flock together” and it has been studied across a wide range
of settings, attributes and relationships (Shrum et al., 1988, McPherson et al.,
2001). More specifically, homophily states that actors prefer to be related to
others who show similar characteristics. Looking at Figure 2b, this means that
ties between Ego and Alter which are similar with respect to a certain attribute
(indicated by the same colour of the node) are more probable than those
between actors who differ with respect to it. For instance, many friendship
studies proved that ties between people of the same gender and race are more
probable than those between people of different gender or race. Finally, when
two or more actors show the same pattern of relationships (Figure 2c), that is
8
9
For more details regarding how the indicator was constructed, see Paterno et al., 2008.
For Figure 2, 3, 4 and 5 see Brandes et al., 2004 and the webpage http://visone.info/.
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GIULIA RIVELLINI – LAURA TERZERA – VIVIANA AMATI
considered to be balance (Cartwright et al., 1956; Wasserman et al., 1994). In
terms of friendship, this suggests that Ego and Alter agree in their friendship
choices since they choose the same people as friends.
Figure 2 – Reciprocity, homophily and balance effects.
To disentangle these effects and to investigate the ties connecting the
members of a group or system, a closed network approach is necessary. In our
context, the close network is defined by the classmates and the friendship relationships existing among them.
To collect the relational data, part of the questionnaire in Lombardy was
dedicated to measuring the complete emotional and instrumental network
(McCallister et al., 1978) of children in the classes involved in the analysis,
based on the research experience in the Netherlands (cfr. Baerveldt et al., 2004).
Each child was asked seven questions, constructed according to the name generator method, starting with a list of individuals who answered by indicating one
or more schoolmates belonging to that list and identified by a number. Two of
the questions concern emotional support measured mutually (Which pupils have
you helped in hard times, such as in a conflict with other people, getting a bad
mark or being taken for a ride? Which pupils helped you in hard times, such as
in a conflict with other people, getting a bad mark or being taken for a ride?).One
question measured the emotional support in one direction (Who do you talk to
about personal problems?). Two questions measured the instrumental support
mutually (Which pupils do you help with practical problems such as doing
homework and projects or organizing a party? Which pupils help you with practical problems such as doing homework and projects or organizing a party?).
One question related to a best friendship (Who are your best friends?) and another regarded negative relationships (Who do you avoid to stay with?). In practice,
the case method calls for each student to indicate pupils within the class and this
is why we deal with a complete network and direct graph.
Although the questionnaire provides direct information concerning
friendship through the item “Who are your best friends?”, a previous analysis
revealed that friendship is not uniquely defined and experienced among kids.
More specifically, girls seem to be less involved in friendships with class6
INDIVIDUAL, DYADIC AND NETWORK EFFECTS IN FRIENDSHIP RELATIONSHIPS
mates, in the sense of the number of people indicated as best friend (Rivellini et
al., 2008). Also psychological literature on the topic tells us that, at this age, the
females view friendships more introspectively, intimately and base them on verbal exchanges. As a consequence, friendships between girls are less focused on
quantity and/or action, and more on the intensity and depth of the relationship.
In other words, boys consider friendships in a more general way, while girls
assign it a less generic meaning (Confalonieri et al., 2005; Petter, 2007).
Consequently, it was considered more appropriate to use the question “Who
do you talk to about personal problems?” as a proxy of friendship for the construction of the closed network. This limited the definition of friendship in this
study to the emotional setting of exchange and confidence.
We should also note that at the survey time, some students could be absent.
The kids present in class could mention the missing ones, but clearly the potential reciprocal ties could not be gathered. For this reason the descriptive analysis
was restricted only to a narrow number of classes (n=349) with respect to the
total number of available classes (n=571) according to the percentage of students
present (at least the 80%)10. The estimation of a statistical model (sec. 2.2)
required a further reduction of the analysed data. Due to the rather time-consuming estimation process, only the province of Milan, with a total of 99 classes, was
taken into account. This is not counterproductive for the results interpretation,
since the province of Milan is a metropolitan area which encompasses a higher
portion of foreign residents in Lombardy who attend public schools (the 45% in
2006, Blangiardo, 2007). Restricting the sample to only one province also has
another statistical reason. Adding another source of variability at the provincial
level implies modelling an additional source of variability which requires a complex definition of the model and of the related estimation procedure.
A stochastic model makes it possible to investigate the regular patterns of
complex social behaviours underlying the friendship process, taking into account
random factors which derive from competing unknown explanatory variables. In
addition, which structures play a key role in the global network configuration can
be determined and their precise contributions can be quantified (Robins et al.,
2007). For instance, clustering in networks could arise for two different reasons.
The former depends on a “homophily” effect. The latter involves an endogenous
balance type effect. Just to clarify, let us consider friendships among people. A
subset of actors can be observed because they show the same characteristics,
such as the same gender, ethnicity or status. Thus, friendship can be explained
by a “likeness attraction” stated by the well-known social identity theory (Tajfel
et al., 1979; Stets, 2000). This theory states that people have a spontaneous tendency to form groups since they need to recognize themselves as part of a
group defined by a specific identity. The social identity stresses the differences
10
The classes excluded from the analysis show a slightly higher mean percentage of immigrant’s
children (20.6%, vs. 18.1%) and a wider range ([0; 66.7] vs. [3.6; 66.7]). The percentage of mixed
pupils is nearly equal to that of the classes included in the analysis (4.8% vs. 4.7%).
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GIULIA RIVELLINI – LAURA TERZERA – VIVIANA AMATI
between the membership groups and the others, leading to clusters in the population and limiting the formation of ties among the people of a different
group. If social identity is based on ethnic characteristics, then people will prefer intra-ethnic rather than inter-ethnic relationships. Another possibility to
explain network clustering relies on the structural balance theory (Cartwright
et al., 1956; Davis, 1963). It states that actors prefer to be related to people
who are in turn related to themselves in order to avoid conflicts and tensions.
For instance, this means that a person tends to establish friendships with
friends of his/her friends. Thus, if these friends avoid inter-ethnic relationships,
s/he will avoid them as well. If we want to distinguish between these two
effects and determine their proper role, a stochastic model should be estimated, so that it is possible to evaluate the net contribution of each effect.
2.2 Choice of statistical model
Statistical models analysing relational data aim to explain the presence of
ties between two actors i and j on the basis of covariates measured at the actor
(e.g. gender, ethnicity and so on) or dyadic (e.g. being in the same office, working together) level and the pattern of ties which give rise to the entire network
structure (such as reciprocal dyads and triads).
Although social network models have been proposed in the literature since
1951 (Solomonoff et al., 1951), interest in network modelling has increased
since 1981, when Holland and Leinhardt introduced the well-known p1 model as
a reaction to the “paucity of statistical tools available” for analyzing social network data (Holland et al., 1981). This model describes the presence of ties
between a pair of actors assuming that there is independence among couples of
actors and not taking into account covariates. For this reason in the 1990’s the p2
model was proposed as an extension of the p1 model (Lazega et al., 1997; Duijn
et al., 2004). It allows for the inclusion of covariates but still assumes dyadic
independence. Further steps are the Markov Graph Model (Frank et al., 1986)
and its generalization, the Exponential Random Graph Model (ERGM) which
also overcomes the independence among dyads and introduces the idea of conditional dependence (Wasserman et al., 1996; Wasserman et al., 2005).
All these models analyze one network at a time. Sometimes the same relationship is collected on different sets of actors so that there are several networks
which should be investigated. Two major attempts to deal with multiple networks
have been made in the literature. The former consists of estimating a model for
each network and then applying a meta-analysis on the models coefficients (Lubbers, 2003; Baerveldt et al., 2004; Lubbers et al., 2007). The latter defines a multilevel model which properly takes into account the three-level hierarchical structure that arises in the case of multiple network observations (Zijlstra et al., 2006;
Baerveldt et al., 2007; Vermeij et al., 2009): the ties (first level) which are nested in the actors (second level) who are embedded into the networks (third level).
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INDIVIDUAL, DYADIC AND NETWORK EFFECTS IN FRIENDSHIP RELATIONSHIPS
The first approach can be applied both in the p2 model and the ERGM, while the
second is currently implemented only for the p2 model.
The structure of the available data naturally oriented the choice of the
model towards a multilevel approach. In fact, classes and friendship relationships within students clearly defines multiple network observations. This
means that each class constitutes a network which provides information about
friendship mechanisms.
Both of the methods previously outlined can be applied. On the one
hand, the meta-analysis approach allows us to relax the independence
assumption among dyads through the estimation of ERGMs, one per each network. This implies that more complex dependence structures can be included
in the model specification. Among them, the literature on friendship relationships suggests that transitivity can be really important. This effect can be
described using the well-known phrase “the friend of my friend is also my
friend”. Some network studies proved its significant role in friendship relationships (Moody, 2001; Lubbers, 2003).
On the other hand, the p2 multilevel model does not include complex
dependence structures, but it allows for the analysis of all simultaneous and
available networks, taking into account the variability within the networks,
i.e. the variability between class networks which can be explained through
specific class characteristics, as well as individual and dyadic characteristics.
Thus, the choice between the two approaches relies on the importance given
to the dependence hypothesis and to class traits. Since classes significantly
differ in terms of number of students, gender, and ethnicity composition
(Table 1), the multilevel p2 model seems to be more adequate, based on the
currently available literature.
Table 1 – Classroom composition (n=99). Province of Milan, 2006
Source: Processing of Lombardy ITAGEN2 data
2.2.1 Formulating the model
Let Y be a network defined by a dichotomous directed relationship col9
GIULIA RIVELLINI – LAURA TERZERA – VIVIANA AMATI
lected on a set of g actors. Y can be represented as a g x g adjacency matrix,
whose generic cell yij takes value 1 if there is a tie between actor i and actor
j and 0 otherwise.
The couple of values Dij = (yij,yij) defines a dyad. Four different kinds of
dyads can be identified. If there are no ties between i and j, the dyad is null
(Dij = (0,0)); if there is only a tie between the two actors (from i to j or from
j to i) the dyad is asymmetric (Dij = (1,0) or Dij = (0,1)); finally if both ties
are present the dyad is reciprocal (Dij = (1,1)).
The p2 model11 is a multinomial regression model which expresses the
probability of observing one of the four possible outcomes of a dyad, according to endogenous network characteristics and actors covariates. The endogenous network characteristics include patterns of ties existing in the network.
Examples of these are the number of outgoing ties (outdegree or density) and
the reciprocal dyads. Actors’ covariates refer to individual attributes, such as
gender, ethnicity, etc. This implies that social network models represent the
global network configuration, taking into account both the properties of nodes
and the pattern of ties existing among them. More specifically, the p2 model
explicitly models the sender and receiver propensity according to individual
attributes, as well as the density and the reciprocity effects according to
dyadic explanatory variables. A positive effect of an individual or of a dyadic
covariate can be interpreted as an increased probability that the tie exists.
Let us look at each effect in more detail, describing it and explaining how
to interpret the corresponding parameter.
Sender and receiver effects. The sender effect is related to the wellknown concept of “expansiveness”, which is measured by the number of outgoing ties of a node and expresses the activity of a node in sending ties. This
can be illustrated graphically by the exit lines (a directional line - arrow - for
each classmate cited) sending from the node that represents a generic student.
For instance, Figure 3 shows, how Student A is more expansive (more exit
arrows) than Student B or Student C.
Figure 3 – Three examples of graphical representation of expansiveness.
11
The statistical formulation of the model is described in Zijlstra et al., 2006.
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INDIVIDUAL, DYADIC AND NETWORK EFFECTS IN FRIENDSHIP RELATIONSHIPS
On the other hand, the receiver effect refers to the “popularity” concept
and it is measured by the number of incoming ties of a node. Thus, it interprets how much an actor is likely to be chosen as a termination of a relationship. This concept is illustrated by the arrows pointing to a node and Figure 4
shows that Student A, receiving two ties, is the least popular, while Student B
is the most popular.
Figure 4 – Three examples of graphical representation of popularity.
Density and reciprocity effects. Density is defined as the number of lines
existing in a network or as the ratio of the number of lines and the maximum
number of possible ties which could be present in a network with g actors. For
instance, Figure 5a represents a network which includes 6 nodes and 11 lines
(arrows). There are two different kinds of parameter in the model which help
in modelling the density. They are related to the overall density and dyadic
effects. The parameter corresponding to the overall density effect can be interpreted as the log-odds of the probability of observing a tie. If it is negative,
the probability of a relationship is smaller than 0.5 when all other parameters
and the random effects are equal to zero. This indicates that networks are
rather sparse (i.e. have low density). The presence of ties can also be
explained by actors’ attributes, but since a tie involves a pair of nodes, the
attributes of both actors should be considered. This explains why we have to
use “dyadic-covariates” (instead of the individual covariates) to model the
density. In more detail, dyadic covariates can be collected on pairs of actors
or defined by actor attributes. In this second case, they are usually computed
in terms of difference or absolute difference of actor attributes. A positive
density effect of an absolute difference in gender suggests that a tie between
two girls or two boys is less probable than a tie between a girl and a boy.
Reciprocity is a more complex effect which measures the tendency
towards symmetrical relationships (Figure 5b), as described in the previous
paragraphs. Since it refers to pairs of ties it can be considered a sort of interaction effect. A positive value of the overall reciprocity parameter suggests
that symmetrical dyads are more probable than asymmetrical ones. Reciprocity can also be modelled including dyadic covariates which can be interpreted similarly to those of density, with the only requirement being that dyadiclevel variables are modelled both for density and reciprocity.
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GIULIA RIVELLINI – LAURA TERZERA – VIVIANA AMATI
Figure 5 – Density and reciprocity effects.
Random effects. The multilevel approach also requires the introduction
of random effects on both individual/actor and network levels (Zijlstra et al.,
2006). They take into account and measure possible differences existing within networks or between the networks, respectively. More specifically, the differences within networks are taken into account including random effects at
the sender and receiver level (i.e. at the actor level). If the sender and receiver variances are significant, it means that actors differ in their expansiveness
and popularity tendencies. Regarding the relationship between sending and
receiving ties, if the covariance is positive, then people who are more popular are also more expansive, while if it is negative there is a trade-off between
sending and receiving ties. The differences between networks are modelled
including random effects to density and reciprocity level (i.e. at the network
level). If variances are significant, networks differ in density and reciprocity.
Furthermore, if the covariance is positive it suggests that the denser the network, the higher the presence of reciprocal dyads.
In order to estimate the parameters of the model it is convenient to use
MCMC methods because the maximum likelihood estimation of the random
effects requires the solution of intractable integrals (Zijlstra et al., 2009). The
p2 model and its multilevel extensions are implemented in StOCNET (Boer et
al., 2006).
3. DESCRIPTIVE RESULTS
3.1 Outside school friendship
Before going into the core issues, we shall give a general overview gathered from survey data on pre-adolescent children of immigrants. Only onefifth of these kids were born in Italy, although that number rises to more than
30% if we take into account those who, born in another country, came to Italy
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INDIVIDUAL, DYADIC AND NETWORK EFFECTS IN FRIENDSHIP RELATIONSHIPS
before starting school (i.e. before the age of 6). A slightly smaller percentage
(27%) arrived in Italy less than three years prior to the survey after already
completing part of their schooling in their country of origin. The main nationalities of origin reflect those of the adults, although the prevalence breakdown
is different: Albanians, Moroccans, Chinese and Rumanians. Again, most of
the kids live with their parents, whether Italian or of foreign origin.
Their diversity lies in the size of the family. More often it is the foreigners who live in extended families (for economic reasons in most cases). Likewise, they have multiple siblings (more than 2) (see Casacchia et al., 2008).
One final remark concerns the knowledge of the Italian language which
is an essential tool for forming relationships outside a child’s community of
origin. In this respect, the data samples show that, apart from the key role
played by the length of time spent in Italy, some interesting differences
emerge regarding immigrants’ fair knowledge of Italian. Pre-adolescents of
African origin are those who apparently learn the language better; East Europeans seem to learn it more rapidly; as for Asians, learning is slower but in
any case remarkable; the case of children from Latin America seems more
problematic because, after an initial advantage (due to the similarity between
the languages) they are often involved in forms of ethnic and linguistic resocialisation as a defence mechanism against forms of exclusion (see Gilardoni, 2008).
We now focus on the core of the analysis. Firstly we consider a general
description of the friendships outside school, as related by the kids. The
‘friendship strategy’ indicator shows that about 42% of foreign-origin kids
can be labelled as “integrated”, by which we mean they have both Italian and
foreign friends (whom they also see outside school). On the other hand,
almost one-third see solely Italian friends (assimilation strategy) and, as a
result, more than 70% of the foreign-origin preadolescents say they have good
relationships with the Italians. We then find the less common case of the “segregated” - less than 20% - (i.e. those who say they have and see prevalently
foreign friends) and, ultimately, the more problematic group made up of kids
labelled “marginalised” (about 6%), i.e. those who say they have few or no
friends, either Italian or of foreign origin.
The scenario changes when we add other interpretative factors such as
country of origin, socialization and gender. Looking at gender, Table 2 shows
girls are at a disadvantage. They seem to be more marginalised, segregated
and less integrated in friendships outside school. Regarding the country of
origin, data suggest that kids of Asian origin experience the biggest difficulty
in making friends, especially with Italians (Table 3), while the Africans are
much more integrated or assimilated.
13
GIULIA RIVELLINI – LAURA TERZERA – VIVIANA AMATI
Table 2 – “Friendship strategy” of foreign pupils by gender. Lombardy, 2006
Source: Processing of Lombardy ITAGEN2 data
Incidentally, these differences are also influenced by the key role of socialization (Table 4): friendships grow and are consolidated the longer the kids spend in
the host society. By this, we underscore that we do not mean an exclusion of friendships with the foreigners, but, to the contrary, an intensification of those with Italians. For instance slightly more than 40% of kids born in Italy identified themselves as assimilated, while among the kids socialized elsewhere, only 24% were
assimilated. This, for example, might help explain the stronger assimilation of
North Africans, the community with one of the longest migration traditions in Italy.
On the other hand, if we consider Asian children, their stronger isolation
is not mainly attributable to widespread socialisation having taken place
abroad or even to difficulties caused by the substantial differences between
languages, because these are apparently overcome soon after they have
arrived in Italy. Among these kids other cultural factors (such as habits, traditions, values, belonging to more encapsulated communities) seem to have a
greater impact on their relational behaviour (Dalla Zuanna et al., 2009).
Table 3 – “Friendship strategy” of foreign pupils by origin. Lombardy, 2006
Source: Processing of Lombardy ITAGEN2 data
Table 4 – “Friendship strategy” of foreign pupils by socialization. Lombardy, 2006
Source: Processing of Lombardy ITAGEN2 data
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INDIVIDUAL, DYADIC AND NETWORK EFFECTS IN FRIENDSHIP RELATIONSHIPS
The same analyses, restricted to the classes surveyed in the province of
Milan, were performed. The regional patterns described in the previous paragraphs were observed without any noteworthy differences (provincial results not
shown).
3.2
Inside school friendship
Considering friendships inside classrooms (through the question “Who
do you talk to about personal problems?”, as we discussed in paragraph 2.1),
we can now analyse how expansiveness and popularity change with respect
to preadolescents’ characteristics.
At this point, the Italian consolidated strategy of newcomer integration
in schools plays a key role (see Mussino et al., 2012). Usually, a new foreign
pupil is placed in one or more grades below his/her age group, assuming that
this will give him/her more time to learn and will reduce the number of future
exam failures. However, that proved to be an unsuccessful strategy, especially at the adolescent age (our case) and for establishing friendship ties within
the class/grade. The diffusion of that strategy also emerges from the entire
survey: among the foreign-origin kids attending lower secondary school at
least half of them were one year behind, a fact that can be attributed not so
much to failing their exams but more to the choice of which grade they are
placed in upon arrival in Italy (see Casacchia et al., 2008). In addition, the
data shows that the percentage of pupils who are at least two school years
behind is definitely not marginal. In fact, in a class made up of 12-13 year
olds, just under one-third of the foreign-origin pupils were aged about 15, an
age at which it is consequently hard to forge ties and which carries a high risk
of isolation. Moreover, we can observe that the more the pupil falls behind in
school, the less importance they give to making friends with their classmates.
Table 5 – Expansiveness and popularity by gender. Lombardy, 2006
Source: Processing of Lombardy ITAGEN2 data
15
GIULIA RIVELLINI – LAURA TERZERA – VIVIANA AMATI
The analysis of expansiveness and popularity reveals that both gender
and area of origin are discriminating factors. Table 5 shows that girls are more
popular and more expansive with respect to boys, indicating that they express
their personal problems more often than boys within the classroom setting.
Similarly, Table 6 suggests that the Italians are more expansive, but, above
all, more popular than the foreign kids. Among Italians less than one third
showed low levels of expansiveness and popularity. Among children of foreign
origin, there is a higher concentration in the lower levels (more than 40% show
low expansiveness and almost the 50% also rates a low level of popularity).
Kids of Eastern European and sub-Saharan African origin are the most
expansive, scoring similarly to the Italians. Vice-versa, the less expansive peers
are the Asian (already noted as those also experiencing greater relational difficulties outside school) and the students from Latin America. We need to remember that the arrivals just before the survey date (2006) are largely made up of
these latter, triggering adaptation difficulties. In terms of popularity (mainly
lower than the levels of expansiveness regardless of origin), the kids of Eastern
Europe and sub-Sahara origin are more successful in becoming popular among
their classmates. On the other hand, the lowest levels of popularity were scored
not only by Latin Americans and Asians (mainly due to the reasons indicated earlier), but also by the African-origin pupils. The fall in this latter group compared
with expansiveness can possibly be explained by the diffusion of negative
stereotypes in Italian society about people from Islamic countries.
In an “intermediate” position regarding friendship relationships in the classroom, there are students of mixed origin (i.e. with one Italian and one foreign
parent). These kids are not as unpopular as the foreigners, although they are less
sought after than Italians; on the other hand their activism in friendship is comparable to that of the most active foreigners in the classroom.
Table 6 – Expansiveness and popularity by origin. Lombardy, 2006
EE = Eastern Europe, A = Asia, NA= North Africa, SSA = Sub-Saharan Africa, LA = Latin
America, M = Mixed, I = Italian
Source: Processing of Lombardy ITAGEN2 data
16
INDIVIDUAL, DYADIC AND NETWORK EFFECTS IN FRIENDSHIP RELATIONSHIPS
Finally, the role played by socialization is pointed out again (Table 7).
Kids who fully socialize in Italy score similarly in the popularity and expansiveness to the Italian pupils. Therefore, the more time a person spent in the
growth and training phase outside Italy, the less likely they are open up to others or chosen as a friend by other classmates. For example, those who were
socialized “elsewhere” in most cases score low on expansiveness (52.8%),
but even more remarkably low on popularity (62%).
Table 7 – Expansiveness and popularity by socialization. Lombardy, 2006
Source: Processing of Lombardy ITAGEN2 data
We conclude the descriptive part with some useful considerations about
the concept of homogeneity, trying to identify who chooses whom and if similar pupils attract or reject each other. Here, we focus on two aspects: the ties
of gender; and the ties of origin. In terms of gender, it is clear that at this age
friendships develop mainly between individuals of the same gender: boys say
they have prevalently other boys as friends and, likewise, girls say they have
mainly other girls as friends, revealing closure with respect to gender.
Table 8 – Homogeneity by gender. Lombardy, 2006
Source: Processing of Lombardy ITAGEN2 data
Regardless of their area of origin, the children clearly show a predominance of friendship relationships with Italians. This tendency can be justified
mainly by the natural prevalence of Italian kids in the classes (see Table 1).
Another interesting result is that Italians are more involved in mixed friend17
GIULIA RIVELLINI – LAURA TERZERA – VIVIANA AMATI
ship relationships with sub-Saharan Africans and less with Asians. The friendship relationships between foreigners with the same origin are not frequent
(the highest score, 15.5%, is registered among Asians who, as already noted,
tend to interact with peers of the same origin more than with other foreigners)
due to the low percentage of foreigners in the classes, in particular of the same
nationality. Similarly, Italian kids are less involved in inter-ethnic ties.
Table 9 – Homogeneity by area of origin. Lombardy, 2006
EE = Eastern Europe, A = Asia, NA= North Africa, SSA = Sub-Saharan Africa, LA = Latin
America, M = Mixed, I = Italian
Source: Processing of Lombardy ITAGEN2 data
In this case, the analyses performed on the province of Milan reveal
some differences. It is noteworthy that the distribution of expansiveness both
for boys and girls is slightly more concentrated on low and medium values,
while for popularity no clear differences appear between province and region
(provincial results not shown). Furthermore, the homogeneity analysis by
area of origin underlines a higher preference of East-European children in
making friendship with classmates of the same origin. Such differences are
mainly attributable to a more diverse composition by area of origin of the
respondents at regional level, compared to the provincial area. This is due to
the difference in the size of the groups in the two territorial areas. This is the
reason for introducing the area of origin covariate as part of the model illustrated in the following section.
4. RESULTS OF NETWORK MODEL ESTIMATION
To validate the results deriving from the descriptive analysis, a p2 multilevel model was estimated from the 99 classes (networks) surveyed in the
province of Milan. There were 1,961 children considered in the analysis.
Among them, 49.8% are boys, 20.5 % are children of immigrants and 5.5% are
mixed pupils.
The model includes the overall network parameter related to density and
reciprocity, as well as dyadic and individual effects. At the dyadic level, covariates connected to gender and area of origin were considered in order to test the
existence of homophily with respect to these attributes. Given the variety of geo-
18
INDIVIDUAL, DYADIC AND NETWORK EFFECTS IN FRIENDSHIP RELATIONSHIPS
graphic regions from which the students stemmed, the area of origin was codified into three categories, distinguishing among Italians, foreigners (both parents
born in CHEL) and mixed-origin pupils. The codification prevents the introduction of too many dummy variables and also solves the problem related to the ethnic composition of the classes. Given the variety of migrants’ citizenships on
Italian soil, it was unlikely that two or more children of migrants coming from
the same country or national area attended the same classes.
At the actor level, some variables were considered to investigate the
sender and receiver attitudes. Previous descriptive analysis showed that gender
and socialization can be potential explanatory variables for expansiveness and
popularity. To test if boys and girls really adopt different strategies in making
friends and if the time of arrival in Italy influences friendship relationships,
gender and socialization were included in the model12. Finally we checked the
importance of school friends. It is well-known that building and maintaining a
relationship involves both costs and benefits. We can assume that higher the
importance given to friendship with classmates, the higher the perceived benefit. Thus, we expect that kids who believe in the relevance of having friends
at school are more encouraged to both make (sending) and be (receiving) in
friendship relationships. Nevertheless, without longitudinal data, we cannot
investigate any causal relationship between being active and popular and the
importance of having friends in school.
Finally, the random effects were included in the model both at the actor
and network level. The estimates of the p2 model are contained in Table 10.
The negative value of the density parameter (-3.673, p-value < 0.01) shows
that the probability of the existence of a confidential friendship relationship
between peers is less than 0.5, when all the other effects (random and not random) are equal to zero. This finding is consistent with the very low values of
network density (density values vary between 0.0254 and 0.6176 with a positive skewed distribution). There is a high tendency towards reciprocal choice
among the few existing ties, as suggested by the positive estimate of the reciprocity parameter (3.026, p-value < 0.01). In other words, there are few confidential friendship relationships but they tend to be symmetrical defining an
out-and-out relationship of blind trust.
The estimates associated with the dyadic covariates support the thesis that
gender and ethnicity (area of origin) are associated with homophily, as
revealed by the descriptive analysis. More specifically, the negative effect of
12
According to the Italian strategy of newcomer integration, described in the previous paragraph,
we should include in the model also the age gap in those pupils who are placed in classes that do
not correspond to their age. In fact, different ages mean different needs and this could obstruct
the arising of friendship relations. Since the variable related to the delay in age is highly associated to the socialization (x2=491.94, df=4, p-value < 0.001), this variable was omitted.
19
GIULIA RIVELLINI – LAURA TERZERA – VIVIANA AMATI
the absolute difference in gender (-1.780, p-value < 0.01) indicates that the
probability of observing a dyad decreases as the difference between the two
actors increases. This effect is also reinforced by the positive value of the gender reciprocity parameter (1.047, p-value < 0.01). Regarding ethnicity, a different pattern is observed. The density coefficient is negative for the foreign
pupils, but positive for the mixed (-0.402 vs. 0.235, p-value < 0.01), suggesting that the former are less involved in friendship relationships than the latter.
The reciprocity coefficient is significant only for the mixed peers (-0.545, pvalue < 0.01) who prefer children/pupils of mixed couples.
At the actor level, gender, socialization and importance of friends at
school only play a partial role. Regarding gender, girls are more popular than
boys (0.437, p-value < 0.01) and entrust more personal matters in their friendships, while no gender difference arises according to the sender attitude. The
same pattern is observed with regard to socialization. In this case, pupils that
arrived after their tenth birthday are less popular then children who came to
Italy in pre-school ages, as pointed out by the negative coefficient associated
to socialization (-0.628, p-value < 0.01).
The high importance given to the schoolmates as friends is significant
both for the sender and for the receiver (0.584 and 0.414 respectively, p-value
< 0.01). In particular the positive association between the high importance
and the expansiveness/popularity indicates that pupils who considered classmates very important are more involved in confidential relationships.
Finally, the model provides random effects. The three actor-level effects
are statistically significant indicating that actors differ both in popularity and
the expansiveness attitude. Furthermore, the negative value (-0.472, p-value
< 0.01) of the covariance between these two tendencies shows that the more
popular a pupil is, the less expansive he/she is. Thus, the less expansive peers
are seen as perfect secret keepers and, for this reason, they are chosen by a
higher number of people as confidant.
At the network-level, the parameter estimates suggest that networks differ in the presence of ties (the density variance is significantly different from
zero), while no differences related to reciprocity are observed. The covariance
between these two structural properties is positive (0.202), revealing that networks with low density are characterized by a higher tendency towards reciprocal ties. In other words, one can say that a lower number of relationships
means more consolidated ties.
20
INDIVIDUAL, DYADIC AND NETWORK EFFECTS IN FRIENDSHIP RELATIONSHIPS
Table 10 – Coefficients and standard errors of p2 multilevel model.
Province of Milan, 2006.
* p<0.05; ** p<0.01
Source: Processing of Lombardy ITAGEN2 data
21
GIULIA RIVELLINI – LAURA TERZERA – VIVIANA AMATI
5. CONCLUSIONS
The analysis of friendships inside and outside the classroom proved useful in order to study the social integration of immigrants’ teenage children. It
was observed that immigrants’ children are often less popular or more isolated within an important reference group, such as the class they attend. On the
other hand, some individual characteristics, such as their migration history,
may affect their relational situations. For example, greater difficulties in being
integrated among children of the same age are more often due to cultural factors among Asians, to a longer socialization outside of Italy, as in the case of
Latin Americans, or to a more discriminatory attitude towards people from
North Africa, as shown by the more limited likelihood of being chosen as confidant among classmates.
Other individual and relational characteristics affect the pupils’ way of
interacting. Descriptive analysis shows that girls and boys clearly differ in the
friendship formation. The relational approach (more or less expansive/more or
less popular) varies depending on the friendship definition underlying the
question posed. The more one focuses on the confidential/intimate dimension
of the relationship (friends regarded as persons with whom you can talk), the
more girls stand out. On the other hand, the more generic the definition of
friendship (friends seen as playmates, for example), the more boys are indicated as friends. Subsequently regarding the question analysed in this paper, it
appears that while boys are less expansive and popular, girls are more active
in making close and intimate friendship relationships among classmates. This
difference, however, should not be entirely interpreted as a male disadvantage
or shortcoming. On the one hand, it is necessary to explore more specifically
the different dimensions of friendship (frequency of meetings, intimacy
achieved and mutual exchange of material and psychological support). On the
other hand, it would be important to consider the individual view of friendship.
Nevertheless, the network analysis highlighted that the existence of a
friendship tie is explained not only by the individual characteristics of the kids
observed as independent entities. One should also consider the features associated with the pair of actors and the overall structure of the network which can
influence a friendship relationship (endogenous feedback). For example, considering homophily with respect to gender and area of origin, intra-gender and
intra-ethnic tendencies clearly emerge, confirming the identity theory.
In general, descriptive results are confirmed by the model estimation: the
intimate friendship relationships mainly consist of pairs or components which
are not numerous, but they are characterized by a higher tendency towards
reciprocity. In the case of a relationship between two individuals, the model
highlights the closure with respect to gender (reinforced also by the reciprocity effect) and the inter-ethnic traits. Friendship relationships are more likely
among those of similar origin than between foreign and mixed pupils. In par22
INDIVIDUAL, DYADIC AND NETWORK EFFECTS IN FRIENDSHIP RELATIONSHIPS
ticular, homophily characterizes the relationships among the former but not
the ties among the latter.
No difference in the sender attitude (expansiveness) is related to gender
and socialization, while they are statistically significant in explaining popularity. There are no differences in the tendency to look for friends, but there are
differences in being chosen as a close friend. Furthermore, there is a negative
trend between expansiveness and popularity as stated by the actor-level random effects. This suggests that pupils who declare that they have a lot of
friends are less frequently chosen by others as friends. Thus, someone who
talks about personal problems with a lot of other classmates is considered not
a good confidant, since s/he can reveal to other classmates, who trust and are
close to him/her, the confidential conversation that s/he had with others.
The confidential friendship relationships examined here are, therefore,
rare but deep, consolidated and mutual. This means that with this kind of question the balance theory can not be supported because intimate relationships by
their own nature prefer smaller groups. In this age group, children prefer to
establish ties with those who can keep a secret and will not betray the trust of
the confidant; these are characteristics more frequently associated with girls.
The social network perspective revealed interesting results and also suggested the need for more in depth exploration. In particular, it was observed
that one question is not enough to discover and describe real friendship. Therefore, a step forward would require the use of other network questions about the
sphere of emotional support. With this addition, a multi-relational analysis
would provide a solution to jointly analyze more than one concurrent relationship and a key for studying integration among peers. Having more than one
network calls for an extension of the multilevel model to a multi-relational
approach. This extension still requires work in theoretical and computational
settings, since the hierarchical structure of the data should be taken into
account for each relationship, making the model more complex. For this reason, a multilevel approach has yet not been extended to multi-relational data.
As suggested by the opportunity theory, the school can be a privileged
place where friendships are created and reinforced. This may help immigrants’
children feel less marginalized. It is therefore important to guarantee easy
access and high quality at all educational institutions open to a diverse (in
terms of origin and migration history) student body. It is also important to foster schools as venues where teachers, cultural mediators and families can work
together in order to enhance inter-ethnic socialisation among children as well
as adults because the latter will have a positive spill over effect on the pupils.
The context of potential social integration for preadolescents, however,
can be wider than just the scholastic environment. We should take into account
the relevance of other environments, such as sports, in which preadolescents
often stay together in a group, and exhibit attitudes and conduct themselves
differently from the school environment.
23
GIULIA RIVELLINI – LAURA TERZERA – VIVIANA AMATI
Finally, social integration is - by its very nature - a process which might
take a very long time to complete and which is affected in different ways by
individual characteristics. Only longitudinal data, therefore, make it possible
to observe the dynamics of this process. However, it is necessary to bear in
mind that the process can be accelerated with a positive effect by actions targeted to specific groups of children of different origins, taking into account
their migratory histories and cultural backgrounds.
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