The concept of “self” is regarded as an organizing construct in behavioral sciences, psychology, psychoanalysis, and social sciences [1]. However, the concepts of self, identity, and self-concept have been used indistinctly by various authors. Leary & Tangney [1] reported a list of 67 different terms that refer to constructs, processes, and phenomena related to “self”, “ego”, and “identity”. Moreover, the concept of “self” has been applied in various ways, e.g. as a synonym for the person as a whole, as a synonym for personality, as the subject of experience, as the system of beliefs about ourselves, and as one agent among others.

From a developmental point of view, typical phases and changes e.g. in the ego´s internal structures are described. These are thought to follow a sequential and predictable pattern over time, whereas each structure is regarded to improve the ability of attributing meaning to life´s experiences [2]. However, a broad range of different domains and constituents have been described in the literature which define the construct “identity” and related phases [3]. Moreover, individual development of domains may not occur in parallel. One domain might develop more readily or may be more organized than another. This results in highly individual identity patterns, probably associated with specific strengths, weaknesses, and even psychopathological traits [4]. Therefore, using broad concepts in studying identity with respect to developmental paths and possible changes over time seems to be adequate to promote scientific advancement.

Psychosocial and cultural influences are thought to play a major role in identity development throughout life [5, 6]. In particular, the effects of the society on promoting (or hindering) development of the individual’s identity are of interest [7, 8]. Moreover according to the narrative approach, an individual’s identity is shaped and modified by language and cultural aspects. Consequently, studies of identity should not only focus on absolute constructs but should take into account cultural factors, such as language, mentality, and living conditions.

Identity development is of prominent interest in the context of mental problems. In psychoanalytic and psychodynamic theories, the achievement of an integrated identity is regarded as central for healthy psychological development [9–11] and is viewed as a major task, especially in adolescence [12, 13]. Severe disintegration is linked to the development of personality disorders, especially borderline pathology. In the operationalized psychodynamic diagnostic system (OPD-2)[14], problems related to identity are the central component of axis IV “structure”, extending from identity integration (structured-autonomous self) to disintegration (incoherent self). In the DSM-IV[15], identity disturbance (i.e. “markedly and persistently unstable self-image or sense of self,” p. 654) is included as one of the components of borderline personality disorder. For the new DSM-5[16, 17], “identity” has been discussed extensively to be integrated as a key criterion for diagnosing personality disorders in general, in terms of reflecting one core impairment in self-related personality functioning in a dimensional way (see also Schmeck et al. in this issue).

We have previously described the different concepts of healthy and impaired identity development and presented a model combining psychodynamic, social-cognitive, and clinical psychology aspects [18] and providing an elaborated combination of the central subconstructs discussed in this field. This integrative model formed the basis of the self-report questionnaire AIDA (Assessment of Identity Development in Adolescence) to assess pathology-related identity development in adolescents aged between 12 to 18 years. The questionnaire, prepared by an international expert team, focused on conceptual clarity, the broad capturing of normal and impaired variants of expressing identity, ease of comprehension, and minimal confounding by factors such as culture, socioeconomics, age, and gender by developing appropriate (i.e. “fair”) item formulations (see below).

The items of AIDA are coded for pathology and add up to a total score reflecting the range extending from ”identity integration” to “identity diffusion“. To enable the identification of the scientific and historical rationale of the distinct subconstructs (e.g. compliance with goals, suggestibility, differentiated mental representations) and to promote research concerning possible specific relations to external variables or psychopathological subtypes, the subconstructs are formulated in terms of separated scales and subscales and are used as distinct units, although they are of course regarded as correlated and interacting in complex ways and to jointly form the higher-order phenotype “identity diffusion”.

The distinction of the two main areas (primary scales), i.e. “Discontinuity” and “Incoherence”, is based on social-cognitive psychology (subjective vs. definitory self; see Figure 1) and the OPD-2 definition of a healthy identity as leading to a “subjective feeling of continuity and coherence” [14]. The three subdomains reflect the central psychosocial or functional constituents used in several taxonomies, i.e. “self-related” vs. “social-related” vs. “ability-related”. This leads to a matrix consisting of six areas of pathology-related identity components.

AIDA showed good psychometric properties in a combined sample of German school children (N = 305) and patients of a Swiss clinic (N = 52) with excellent total score (Diffusion: α = .94), scale (Discontinuity: α = .86; Incoherence: α = .92), and subscale (α = .73-.86) reliabilities, justifying the use of theory-based subscales as distinct units [18, 19]. An unrestricted exploratory factor analysis (EFA) on the item level showed a joint higher-order factor “identity integration” explaining 24.3% of variance, while the further 14 components did not match with reasonable units of shared content and only contributed minor explanatory power up to 62.6% in total. This was in line with the expected overall congruence on the phenotype level and was interpreted as an indicator for successful test construction, as all modeled contents/items had been constructed to reflect pathology-related identity development. However, the quality of a theory-based and pathology-oriented inventory, such as AIDA, hinges on the criterion validity, i.e. the potential to clearly differentiate healthy from impaired development. In a study in patients with personality disorder (N = 20) and healthy controls (N = 305), both areas of identity development, i.e. the two AIDA primary scales, demonstrated a remarkable discriminative power [18]. The “Discontinuity” scores differed between the groups with an effect size of d = 2.17 standard deviations and the “Incoherence” scores with d = 1.94 standard deviations (see also Jung et al. in this issue).

In Mexico, the mean age of the current population is 26 years. The population census 2010 revealed a serious problem with school drop-outs among Mexican adolescents and labeled 26% of adolescents aged between 15 and 19 years as “NINIs” (not studying, not working) [20]. As a consequence, adolescent delinquency has increased by 139% in the last six years. Adolescents not attending school or pursuing professional training are particularly at risk of getting involved with drug dealing or organized crime [21].

Mental disorders among adolescents in conflict with the law are common, with prevalences reported to be as high as 60-70% [22] or even 90% [23]. In a large US-American study [24] in 18,607 incarcerated adolescents, 70% of the boys and 81% of the girls showed severe psychiatric symptoms. In countries in which access to mental health services is limited, the prevalence of mental disorders in imprisoned subjects tends to be particularly high [22].

According to Kernberg [25, 26] and Clarkin et al. [27], malignant narcissism and antisocial personality disorder are among the pathologies associated with borderline organization and are often seen in delinquent adolescents. Leichsenring, Kunst & Hoyer [28] found significant correlations between borderline personality organization (including identity diffusion) and antisocial personality disorder traits in violent offenders. Similarly, general behavioral and impulse control problems correlate with borderline personality organization [29].

Our goal was to investigate the relationship between identity development, delinquency, and development of personality disorders in Mexican adolescents. However, validated inventories with specific population norms for studying identity as well as specific pathologies in Mexico are lacking. Therefore, our Mexican team decided to contribute to the development of a Spanish version of the questionnaire AIDA, together with colleagues from Spain and Chile and in cooperation with the original authors. This instrument provides a broad conception, clear links to psychopathological traits, an established reliability and validity, and was constructed with a cross-cultural approach right from the start. Countries participating in the international AIDA study were requested to develop a culture-adapted AIDA version with equivalent content and satisfactory psychometric properties for all items and scales (see below) to enable international pooling of data and permit intercultural conclusions. In the current study, the culture-adapted Spanish translation of AIDA was tested in Mexican school children to evaluate the psychometric properties of items and scales of the questionnaire. The procedures used agreed well with those reported by the original authors for validating AIDA in Germany to provide clear comparability of the results. To evaluate aspects of criterion validity, we assessed a juvenile justice system sample (i.e. “conflict sample”) in which a higher frequency of psychopathological traits and identity diffusion was assumed. Content equivalence and successful test adaption were confirmed if the results obtained were similar those reported in the original study.

Assessment of identity development already in adolescence is important to study developmental paths in general and to enable valid conclusions about specific pathological risks. This is true especially in the light of the new revision of DSM-5, where “identity” has been discussed extensively to be integrated as a core criterion for impaired self-related personality functioning.

The Swiss-German-American questionnaire AIDA provides a reliable and valid assessment of the complex construct “pathology-related identity integration vs. identity diffusion” in adolescents by integrating different theoretical approaches and a reasonable structure of known subconstructs. Valid assessment tools must also meet the requirements of international usability in cross-cultural studies (e.g. as described by the International Test Commission; [35]), to model different phenotypes in different cultures and to enable valid comparisons of identity development in different societies by providing true equivalence in content of the assessment tool.

The Spanish culture-adapted translation of AIDA showed good psychometric properties in the Mexican sample, with similar patterns in results compared to the original version. We conclude that all constructs and subconstructs contained in the AIDA model to constitute “identity development” had been successfully transposed into the “Spanish-speaking culture” with good content equivalence.

However, detailed analysis revealed some problems on the item level in the Mexican sample. In the following, the results are discussed in detail, and suggestions for changes in item formulation with respect to the special need of the Mexican culture are presented. Each class of results is contrasted with the results of the original version to illustrate the special techniques and consequences of cultural test adaption.

Compared to the German items of AIDA, the Spanish items seemed to be “easier to answer in a symptomatic way”, i.e. to say “yes” coded towards identity diffusion in the Mexican school sample. While in the German sample, the mean percentage of symptomatic answers (p_i) was 30% and 20 of the 58 items showed a percentage below 10% [19], in the Mexican sample the mean p_i was 40% and only 3 items showed an extreme value for “difficulty to be answered with yes” with a p_i below 10%. This means that the items were in general more difficult to answer with “yes” in the German version than in the Mexican version of AIDA. Thus, score differences between Mexican and German adolescents cannot be interpreted directly as different levels of identity diffusion because score equivalence cannot be assumed [33]. Therefore, population norms, e.g. T-values extracted from representative populations, have to be used for valid comparisons of samples concerning their “levels of identity development”.

All Spanish AIDA items matched the criterion for item bias and proved to be “age and gender fair” in the Mexican study. This agrees well with the results in the German study. The classical example for explaining “item fairness” is the “soccer item”: it would be unfair to judge the frequency of general physical activity by asking “How often do you play soccer” because girls usually do not like this game as much as boys do. Girls would probably say “never” more often, and therefore would be judged falsely as “physically inactive” in contrast to the boys. As all AIDA items can be regarded as gender and age fair, differences on the score level between gender and age groups can be interpreted as true developmental differences.

Not all Spanish items fully met the criterion for item total correlation (r_it) in the Mexican sample. Four items (items 8, 27, 12, and 20) showed coefficients slightly below the criterion but would be generally acceptable for a translated version, especially taking into account that in all cases the item total correlations were excellent in the delinquent subsample with assumed behavioral problems. As the pooled school sample did not contain any subjects with diagnosed identity diffusion (e.g. a clinical sample with personality disorders), the data variance may not reflect the full range of true variability and relations in total, and the coefficients might be improved when “the pathological side” of the construct could better unfold its effects. Three items showed slightly weak r_it in more than one category or one coefficient far below the preset criterion (items 2, 33, 49). These items should be discussed in detail to detect a possible cultural bias in translation that might be eliminated by improved wording.

Item 2 (“I feel at home in my community, here is where I belong to”) showed the weakest r_it in the delinquent group, and we realized that in Mexico it might be difficult to feel ‘at home’ in a community suffering from a high crime rate. A better wording might be “I am proud of my roots and I feel like belonging to this group” to capture “Discontinuity-relations and roles” in terms of potential identity-giving and stabilizing cultural and/or ethnic roles.

Item 33 (“Just as I was as a child and as I am now, I can imagine how I could be in a few years”) was only slightly below the criterion and might be improved by a simpler wording, i.e. “As time goes by, I can imagine well how I will be in the future.”

Item 49 (“Many people are very "fake" and do not behave the way they really are”) showed a weak item total correlation with r_it = .11 in the subscale-referred analysis and r_it = .18 in the scale-referred analysis in the school sample, implying that this item has too little in common with the variance of the whole scale and the other items. Thus, it is not suitable for the scale “Incoherence-cognitive self-reflection” in terms of having shallow or superficial mental representations. At the same time, the item showed a high r_it = .55 in the delinquent subsample. This can be interpreted as a specific concordance with behavioral problems and may constitute improved quality of the assessment if psychiatric patients are included. Additionally, we realized that calling someone “a fake” is somehow “bad language” in the Mexican society and that students might refuse to respond to such unsuitable questions. To address this, the item should be expressed more politely, e.g. “Many people behave differently from what they really are” to adequately reflect the original wording of “not understanding complexity and variety of others’ behavior”.

Thus, for all “problematic” items, issues with cultural adaption of the contents were considered, and improved formulations were suggested. The high scale reliabilities α, with .94 for the total scale Identity-Diffusion, .85 and .92 for the two primary scales Discontinuity and Incoherence, and .70 to .83 for the subscales, are expected to further improve in the next pilot test with adapted item wording.

As in the German validation sample, the AIDA scores differed with about medium effect size between boys and girls in the Mexican school sample. However, in contrast to the findings in Germany, the Mexican girls showed systematically lower scores than the boys in the AIDA, implying healthier development, i.e. better identity integration. Therefore, differentiated norms for boys and girls should be extracted based on a representative Mexican population sample.

In contrast to the German subjects, Mexican subjects showed systematic differences between the two age groups (12-14 years and 15-19 years) with small to medium effect sizes. Therefore, it can be assumed that in Mexico distinct developmental stages related to age can be found. In line with the general theory of developmental identity, the younger adolescents displayed higher levels of “identity diffusion” without reaching pathological levels. This is viewed as a sign of an expected identity crisis at this age. Given this, differentiated age-specific population norms should be extracted in Mexico.

The socioeconomic background seemed to have no remarkable impact on the adolescents’ identity development in Mexico. Thus, students from different schools can be pooled for statistical analyses without affecting the results.

The EFA on the item level resulted in a very similar factorial structure as the one found in the Swiss-German validation sample. In the Mexican sample, 15 extracted factors explained 66.2% of the total variance with the first component alone explaining already 25.4%, while in the German sample, 15 extracted components explained 62.6% of the variance (first component 24.3%). This clearly documents favorable equivalence and effective culture-specific test adaption for assessing this complex construct in Mexico, as the translated version showed comparable patterns of results in a similar statistical analysis.

The confirmed “i-factor” is in line with the expected overall congruence on phenotype level, as all modeled contents (i.e. items) had been constructed to reflect current pathology-related identity development. The AIDA model combines distinct aspects of healthy identity concerning sources and/or consequences for its development and uses these theory-based distinct units in terms of scales and subscales experimentally to facilitate communication and research. However, empirical confirmation of the assumed structure is needed. As soon as different AIDA versions with convincing basic psychometric properties for item characteristics and scale reliability have been tested in normative samples, the instrument will be tested on the item and subscale level in a multi-sample study with a cross-cultural focus. Optimally, data obtained in various countries and continents should be suitable for pooling to analyze the underlying structure.

Because AIDA is a pathology-oriented inventory, the central quality standard lies in the diagnostic or predictive validity, i.e. the potential to differentiate healthy from impaired development. We evaluated criterion validity of the Spanish AIDA in Mexico by comparing the scores of the school sample to a “clinical sample” recruited from the juvenile justice system sample. The delinquent boys were a highly heterogeneous group with respect to their behavioral problems and comorbidities. The most probable behavioral problem in this subsample, i.e. “externalizing disorder”, is not assumed to be directly associated with severe identity diffusion in terms of “having no inner continuity and subjective self-sameness (Discontinuity)” or “having no consistently defined inner self-picture and autonomy (Incoherence)”. However, we clearly expected relevant consequences for identity development and detectable differences compared to the normal students as identity diffusion can be seen as a basis for several types of psychopathology, and the prevalence of mental disorders has proven to be high in incarcerated adolescents [22–24].

To create a more homogeneous contrast group, we used the Mexican pilot test version of the borderline screening inventory Ab-DIB with Canadian cut-offs. The subgroup of delinquent boys with signs of borderline pathology in this test (N = 14) was compared to the whole school sample on the one hand, and to a school subsample matched for age and gender on the other hand. In both analyses, the delinquent boys showed higher frequencies of identity pathology than the adolescents in the school sample, pointing towards satisfactory criterion validity of AIDA in Mexico. The Discontinuity scores differed with high effect sizes of d = 1.21 and 1.17, and the Incoherence scores with about medium effect sizes d = 0.62 and 0.46 standard deviations between the groups. However, the discriminative power of AIDA in this study was lower than in the original study that contained a true clinical sample of diagnosed PD patients. The strikingly different impact of the AIDA subscales on differentiating between the school and conflict samples implies that it is appropriate to treat the subscales as distinct units in an experimental fashion. Especially the subscales representing the psychosocial function “mental representation”, split into the domains “emotional” (part of Discontinuity; 1.3) and “cognitive” (part of Incoherence; 2.3), showed a different pattern compared to the other subscales. While subscale 1.3 showed a weaker discriminative potential than the other subscales of Discontinuity, 2.3 showed a stronger potential than the other subscales of Incoherence to differ between the school group and the “clinical” group. This may be due to the special characteristics of the delinquent sample with probable current behavioral problems like aggression and externalizing disorders that may be related to specific deficits leading to a special AIDA profile of this group.

The Spanish version of AIDA showed good psychometric properties in Mexico and can be used to assess the construct “pathology-related identity integration vs. diffusion” with reliability, validity, and content equivalence in comparison with the original AIDA questionnaire. This finding supports the cross-cultural generalizability of the underlying concept and confirms the importance of culture-specific test adaption in addition to literal translation of the questionnaire. Nevertheless, some items should be improved. Therefore, the test version of “AIDA Spanish – Mexico” should be further adapted and should be tested in a more heterogeneous population.